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Would the XE256 cause an E58 to have low vacuum? UPDATE #427763 08/03/09 08:39 PM 08/03/09 08:39 PM
Joined: Apr 2007 Posts: 2,327 Glendale, AZ 6 69L78Nova OP Banned. Forever.
69L78Nova OP Banned. Forever. 6 Joined: Apr 2007 Posts: 2,327 Glendale, AZ	I just rebuilt the 360 in my 78 Fury. It is a totally stock rebuild (rings, bearings) with the exception of an XE256 cam. I know the E58s had an actual 7.something to 1 compression ratio, but this cam was suggested by many people, including people on Moparts. My dilemma is, this thing is absolutely gutlass off idle, and is very lazy. The converter is the stock piece and will stall at about 1600. It wont even turn the tires doing a brake torque! The timing is set at 12* initial, and the idle is set at 1100 in park/neutral, but it drops down to about 550 in gear. Vacuum in park is about 16-17, and in gear drops down to about 11-12. Ive tried the timing everywhere from 8* to 15* initial, but fuel economy and performance seems to be best at 12*. Im running a "pre-emissions" Thermoquad, and a standard electronic distributor with an orange box. It pulls like a bat outta hell for what it is once ya get into the secondaries. Is this just not a torquey cam or what? The RPM range for the cam is listed from 1000-5200. Any ideas? This baby is my daily, and Id like to get it running right. Thanks in advance 1969 Nova 454/M21/3.31 Mild mid-11 second weekend cruiser 1994 F150 XLT Super Cab 2WD 5.0/4R70W/3.55 (Daily driver)

Re: Would the XE256 cause an E58 to have low vacuum? [Re: 69L78Nova] #427764 08/03/09 09:07 PM 08/03/09 09:07 PM
Joined: Sep 2007 Posts: 14,889 up yours Supercuda About to go away
Supercuda About to go away Joined: Sep 2007 Posts: 14,889 up yours	Did you degree in the cam? Almost sounds retarded. They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.

Re: Would the XE256 cause an E58 to have low vacuum? [Re: Supercuda] #427765 08/03/09 09:15 PM 08/03/09 09:15 PM
Joined: Apr 2007 Posts: 2,327 Glendale, AZ 6 69L78Nova OP Banned. Forever.
69L78Nova OP Banned. Forever. 6 Joined: Apr 2007 Posts: 2,327 Glendale, AZ	Yeah, sure did 1969 Nova 454/M21/3.31 Mild mid-11 second weekend cruiser 1994 F150 XLT Super Cab 2WD 5.0/4R70W/3.55 (Daily driver)

Re: Would the XE256 cause an E58 to have low vacuum? [Re: 69L78Nova] #427766 08/03/09 09:57 PM 08/03/09 09:57 PM
Joined: Apr 2005 Posts: 1,489 west kentucky G gomangoRTSE pro stock
gomangoRTSE pro stock G Joined: Apr 2005 Posts: 1,489 west kentucky	A cam of this size should NOT cause your engine to have low vacuum. Again as stated your timing is off somewhere.

Re: Would the XE256 cause an E58 to have low vacuum? [Re: gomangoRTSE] #427767 08/03/09 11:09 PM 08/03/09 11:09 PM
Joined: Apr 2007 Posts: 2,327 Glendale, AZ 6 69L78Nova OP Banned. Forever.
69L78Nova OP Banned. Forever. 6 Joined: Apr 2007 Posts: 2,327 Glendale, AZ	Thats what I was thinking. The balancer ring has quite a wobble as well. How likely is it the balancer ring could have spun? This thing has a ton of mid-range and top end, considering Im still running the small stock manifolds and exhaust for the time being. If I bring the stall up and hit it from a stop, it takes off like a 2bbl 318 until it hits around 2000rpm. Granted, I still have yet to adjust the air door and such, but the low idle in gear is whats puzzling. And forget turning the A/C on. Gotta "2 foot" it at idle to do that. 1969 Nova 454/M21/3.31 Mild mid-11 second weekend cruiser 1994 F150 XLT Super Cab 2WD 5.0/4R70W/3.55 (Daily driver)

Re: Would the XE256 cause an E58 to have low vacuum? [Re: 69L78Nova] #427768 08/04/09 12:49 AM 08/04/09 12:49 AM
Joined: Apr 2007 Posts: 2,327 Glendale, AZ 6 69L78Nova OP Banned. Forever.
69L78Nova OP Banned. Forever. 6 Joined: Apr 2007 Posts: 2,327 Glendale, AZ	Also, with the timing set at 12*, it is kicking against the starter when the engine is at operating temperature. That doesnt sound right for an 8.0:1 360 1969 Nova 454/M21/3.31 Mild mid-11 second weekend cruiser 1994 F150 XLT Super Cab 2WD 5.0/4R70W/3.55 (Daily driver)

Re: Would the XE256 cause an E58 to have low vacuum? [Re: 69L78Nova] #427769 08/04/09 09:21 AM 08/04/09 09:21 AM
Joined: Jan 2003 Posts: 16,123 Grand Haven, MI patrick I Live Here
patrick I Live Here Joined: Jan 2003 Posts: 16,123 Grand Haven, MI	Quote: I just rebuilt the 360 in my 78 Fury. It is a totally stock rebuild (rings, bearings) with the exception of an XE256 cam. I know the E58s had an actual 7.something to 1 compression ratio, but this cam was suggested by many people, including people on Moparts. My dilemma is, this thing is absolutely gutlass off idle, and is very lazy. The converter is the stock piece and will stall at about 1600. It wont even turn the tires doing a brake torque! The timing is set at 12* initial, and the idle is set at 1100 in park/neutral, but it drops down to about 550 in gear. Vacuum in park is about 16-17, and in gear drops down to about 11-12. Ive tried the timing everywhere from 8* to 15* initial, but fuel economy and performance seems to be best at 12. Im running a "pre-emissions" Thermoquad, and a standard electronic distributor with an orange box. It pulls like a bat outta hell for what it is once ya get into the secondaries. Is this just not a torquey cam or what? The RPM range for the cam is listed from 1000-5200. Any ideas? This baby is my daily, and Id like to get it running right. Thanks in advance you might have a balancer issue, I don't know. when assembling an engine I usually toss the balancer on with the heads off to check the TDC mark with actual TDC of the #1 piston, just to verify. anyway, I was running a comp XE262 in a stock long block 360 that was rerung, and used the standard .054" gaskets that come supplied in the fel-pro tear down kit, so my actual compression was in the 7.8:1 range. my car had lots of low end with this cam. the key is setting up the distributor correctly. your issues tell me that it is the mechanical advance that needs to be tuned. the 500+ RPM drop when putting it in drive tells me that. what's happening is you're already up on the mechanical advance at 1100 RPM. when you put it in gear, the idle drops, pulling out timing, which drops the RPMs further, which pulls out more timing, until you get to the true base timing and the idle stabilizes (in this case, ~550 RPM). check the timing in gear, I'm guessing it'll be significantly less than your 12 degrees at 1100 RPM. my 360 is a '79. the dizzy that came with it had 30 degrees of mechanical advance, and it started advancing at about 650 RPM. there were 2 springs in it, a very light, and a very heavy spring, so it advanced ~20 degrees very quickly, before 2000 RPM, and the last 10 degrees very slowly, so it wasn't all in until over 4k RPM. I used a dial back timing light on the engine to determine the total amount of mechanical advance the dizzy had by disconnecting the vaccuum advance, and running the RPMS up until it didn't advance the timing any more. then I pulled the distributor out, and disassembled it. I measured the length of the slots in the mechanical advance plate & the diameter of the pin that rides in the slot. I subtracted the two numbers to get the total travel in the slot, and divided it by 30 to get the travel per degree advance. my car idled best with no starter kickback with ~18 degrees base timing, so I wanted 18 degrees mechanical advance, and I needed to remove 12 degrees. so I took my travel per degree calculation, multiplied by 12, and that was how much I had to shorten the slots up. I welded up the slot from the INSIDE some, and then used a small file to fine tune the slot length. welding up the inside of the slot will increase the preload on the advance springs, raising up the RPM they start allowing advance. I played around with a advance spring kit I got from a friend, who ended up locking out the mechanical advance in his MSD distributor (for an EFI app) and the stock light spring from my dizzy to come up with a spring combo (I think it's got the light stock spring, and one of the lightest MSD springs in it) that gives me an advance curve that starts advancing at 1200 RPM, and was all in by 2500 RPM. I have 18 degrees initial, 36 total, and with the 600 eddie carb, I was idling in park at 950 RPM with 17" vaccuum, in gear at 800 RPM with 13" vaccuum, and about 700-750RPM in gear with the AC on and 11-12" vaccuum. you may have other issues (vaccuum leaks, balancer thats off, etc), but you'll never get it to run right without setting up the dizzy for that cam. I'd probably look at as much initial as you can get without starter kickback (I'd expect to get at least 16 with that cam), and 36-38 degrees total mechanical advance, all in by 2500 RPM or so. 1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod SOLD!** 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)

Re: Would the XE256 cause an E58 to have low vacuum? [Re: patrick] #427770 08/04/09 10:58 AM 08/04/09 10:58 AM
Joined: Oct 2003 Posts: 7,506 Az Crizila master
Crizila master Joined: Oct 2003 Posts: 7,506 Az	Agree with patrick in that it's a timing issue ( although I have never seen 30 degrees of mechanical advance in a distributor before ). It sounds as though you have too much timing coming in too soon ( curve is too fast at the bottom end ). You can try replacing the light spring with a heavier one, or to verify that's the case, set the initial timing @ tdc or even a little on the retard side and see if that perks up the low end. It will obviuosly kill the top end ( and the vacuum )but it's just a test to see if the initial curve is too fast. For your set up, I would run about 12 mechanical degrees in the distributor ( 24 degrees @ the crank ) with initial timing at 12 degrees for a total mechanical of 36 dgerees - Curve to start around 1200rpm and all in around 2800 rpm. I'd run about 14 degrees of vacuum advance. This would give you a total of 50 degrees at cruise - 2800 rpm or above. Very common set up for a streeter. Fastest 300

Re: Would the XE256 cause an E58 to have low vacuum? [Re: Crizila] #427771 08/04/09 11:17 AM 08/04/09 11:17 AM
Joined: Jan 2003 Posts: 16,123 Grand Haven, MI patrick I Live Here
patrick I Live Here Joined: Jan 2003 Posts: 16,123 Grand Haven, MI	Quote: Agree with patrick in that it's a timing issue ( although I have never seen 30 degrees of mechanical advance in a distributor before ). It sounds as though you have too much timing coming in too soon ( curve is too fast at the bottom end ). You can try replacing the light spring with a heavier one, or to verify that's the case, set the initial timing @ tdc or even a little on the retard side and see if that perks up the low end. It will obviuosly kill the top end ( and the vacuum )but it's just a test to see if the initial curve is too fast. For your set up, I would run about 12 mechanical degrees in the distributor ( 24 degrees @ the crank ) with initial timing at 12 degrees for a total mechanical of 36 dgerees - Curve to start around 1200rpm and all in around 2800 rpm. I'd run about 14 degrees of vacuum advance. This would give you a total of 50 degrees at cruise - 2800 rpm or above. Very common set up for a streeter. all my degrees I mentioned were in crank degrees off of the damper, so the advance plate actually had 15 degrees in cam degrees, or 30 in crank. degrees. you have it backwards. retarding the distributor will hurt low end, and move the powerband higher in the rev range, because at low RPM's the peak cyl pressure will occur after TDC with it retarded. 1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod SOLD!* 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)

Re: Would the XE256 cause an E58 to have low vacuum? [Re: patrick] #427772 08/04/09 01:09 PM 08/04/09 01:09 PM
Joined: Oct 2003 Posts: 7,506 Az Crizila master
Crizila master Joined: Oct 2003 Posts: 7,506 Az	Quote: Quote: Agree with patrick in that it's a timing issue ( although I have never seen 30 degrees of mechanical advance in a distributor before ). It sounds as though you have too much timing coming in too soon ( curve is too fast at the bottom end ). You can try replacing the light spring with a heavier one, or to verify that's the case, set the initial timing @ tdc or even a little on the retard side and see if that perks up the low end. It will obviuosly kill the top end ( and the vacuum )but it's just a test to see if the initial curve is too fast. For your set up, I would run about 12 mechanical degrees in the distributor ( 24 degrees @ the crank ) with initial timing at 12 degrees for a total mechanical of 36 dgerees - Curve to start around 1200rpm and all in around 2800 rpm. I'd run about 14 degrees of vacuum advance. This would give you a total of 50 degrees at cruise - 2800 rpm or above. Very common set up for a streeter. all my degrees I mentioned were in crank degrees off of the damper, so the advance plate actually had 15 degrees in cam degrees, or 30 in crank. degrees. you have it backwards. retarding the distributor will hurt low end, and move the powerband higher in the rev range, because at low RPM's the peak cyl pressure will occur after TDC with it retarded. 10-4 on the degrees patrick. Peak cylinder pressure ( flame front at its peak )in normally asperated engines should occur around 12 degrees ATDC ( best angle of attack between the piston / rod / crank). If you light the fire too early, this peak flame front pressure will occur too early ( before the 12 degree crank angle ) in the cycle and torque will drop off. If you are lighting the mix too earily ( especially at low rpm's, the motor will be flat. An easy test to verify this is to just retard the distributor ( sets the hole curve back ) and see if it feels better a low speeds. Again, you could also install heavier advance springs - or switch the heavy and light springs - temporarily. Fastest 300

Re: Would the XE256 cause an E58 to have low vacuum? [Re: Crizila] #427773 08/04/09 02:59 PM 08/04/09 02:59 PM
Joined: Apr 2007 Posts: 2,327 Glendale, AZ 6 69L78Nova OP Banned. Forever.
69L78Nova OP Banned. Forever. 6 Joined: Apr 2007 Posts: 2,327 Glendale, AZ	Hey thanks chums. Ill go out there in a little bit and try it. It is at all accurate to get the timing in the ballpark with a vacuum gauge? At any rate, you all offered up some good ideas and hopefully one of them will work 1969 Nova 454/M21/3.31 Mild mid-11 second weekend cruiser 1994 F150 XLT Super Cab 2WD 5.0/4R70W/3.55 (Daily driver)

Re: Would the XE256 cause an E58 to have low vacuum? [Re: 69L78Nova] #427774 08/04/09 04:01 PM 08/04/09 04:01 PM
Joined: Jan 2003 Posts: 2,931 P Paul_Fancsali master
Paul_Fancsali master P Joined: Jan 2003 Posts: 2,931	Forget the 36 degree timing with low comp. I'm running a E-58 360 with 46 total timing all in by 2000. I don't worry about turnig the tires even with TQ like you have I ran upper 14s. With a 750 dbl pumper it has gone 14.30 You are moving 2 tons with that Fury. gear the car at least 3.90s and that car will be fast enough for you. If gas mileage is a real concern consider this my combo gets 12 mpg with 4.56 gears now in a 4300 lb car running at 65 at 4 grand. Keep in mind Mopar bible does not consider engines with 7.5 comp

Re: Would the XE256 cause an E58 to have low vacuum? [Re: Paul_Fancsali] #427775 08/04/09 04:07 PM 08/04/09 04:07 PM
Joined: Oct 2003 Posts: 7,506 Az Crizila master
Crizila master Joined: Oct 2003 Posts: 7,506 Az	Quote: Forget the 36 degree timing with low comp. I'm running a E-58 360 with 46 total timing all in by 2000. I don't worry about turnig the tires even with TQ like you have I ran upper 14s. With a 750 dbl pumper it has gone 14.30 You are moving 2 tons with that Fury. gear the car at least 3.90s and that car will be fast enough for you. If gas mileage is a real concern consider this my combo gets 12 mpg with 4.56 gears now in a 4300 lb car running at 65 at 4 grand. Keep in mind Mopar bible does not consider engines with 7.5 comp With a CR of 8:1 or there abouts you can make lots of mistakes and get away with it. Fastest 300

Re: Would the XE256 cause an E58 to have low vacuum? [Re: Crizila] #427776 08/04/09 04:33 PM 08/04/09 04:33 PM
Joined: Feb 2008 Posts: 992 Simi Valley, CA MoparJ super stock
MoparJ super stock Joined: Feb 2008 Posts: 992 Simi Valley, CA	Hell, my stock internal rebuilt 73 318 with a XE268, headers, along with 600 cfm Edde carb on a performer intake runs great for what it is. I have a 904 with a TF2 kit and a Hughes 2500 TC, with 3.23 gears. The dizzy is a MP piece with a MSD blaster coil. I have as much timing as it will take before it pings somewhat under load, but I have never encountered starter kickback yet. I think my balancer and tape is off, so I may have to just move up and run 89 fuel (as I am running 87) and see how it runs again by advancing the timing. It has run anywhere from 14.6 to 15.2 in the quarter, depending on day and gets 16-19 mpg on the hwy. 2016 Ram 1500 Crew Cab: 5.7, 65RFE, 4.56 gears with locker, Hemifever tuned, AFE intake, 87mm throttle body, JBA headers, 3" Flowmaster exhaust, split to dual 2.5" exits. 13.57 best ET so far. Searching for new A or B Body Project!

Re: Would the XE256 cause an E58 to have low vacuum? [Re: Paul_Fancsali] #427777 08/04/09 05:36 PM 08/04/09 05:36 PM
Joined: Apr 2007 Posts: 2,327 Glendale, AZ 6 69L78Nova OP Banned. Forever.
69L78Nova OP Banned. Forever. 6 Joined: Apr 2007 Posts: 2,327 Glendale, AZ	Quote: gear the car at least 3.90s and that car will be fast enough for you. Im not trying to make the car as fast as I can. Thats what I have my Barracuda for. Im just trying to get this car to run as good as I can, and have it set up properly since I drive it every day. Just to let everybody know, Im not a burnout crazed teenager...just found it odd that it wouldnt break the tires loose. Im going to examine my ignition timing, and possible slippage of the harmonic balancer ring, and go from there. When I put the motor together, I double and triple checked the cam timing this time. Crizila can vouch for my past cam problems. He was a great help the last time. Anyway, Ill try some things and see what happens. Thanks for all of the replies so far 1969 Nova 454/M21/3.31 Mild mid-11 second weekend cruiser 1994 F150 XLT Super Cab 2WD 5.0/4R70W/3.55 (Daily driver)

Re: Would the XE256 cause an E58 to have low vacuum? [Re: 69L78Nova] #427778 08/04/09 10:58 PM 08/04/09 10:58 PM
Joined: Apr 2007 Posts: 2,327 Glendale, AZ 6 69L78Nova OP Banned. Forever.
69L78Nova OP Banned. Forever. 6 Joined: Apr 2007 Posts: 2,327 Glendale, AZ	Well, I just got done messing with it. I tried the timing everywhere from TDC to 25* initial. The engine vacuum went up the farther I advanced the timing, but couldnt get any more than 17.5* or so at 1000rpm. I cheched the timing in gear as suggested and it is the same as it is at 1100rpm. I sprayed around the perimeter of the manifold, carb base and all of the vacuum fittings and plugs on the intake. When the timing is up around 20* base, the engine is very snappy and responsive at both idle and in gear, but it drags the starter when at operating temperature. The stall of the converter seems to vary as well. This is a reman unit that went in with the rebuilt engine, and sometimes it will stall at 1600 or so, and other times 1200-1300. Im thinking the starter is not the culprit either, as I had this starter on my Barracuda at one time and it is running 11.2 to 1, and turned it over just fine. What else should I check? I really cant think of anything else. When the timing is at the 12* I had it at, driveability was good, and MPG was good...but off the primaries, it was just lazy. Taking off semi-hard off of a stoplight, it would almost stumble. The carb had been completely rebuilt right before the engine rebuild and ran like a top. Could it be maybe a little lean now with the addition of the cam? Other than adjusting the metering rods 1 turn up to eliminate part throttle miss at cruising speed, it is as it was with the old motor. Im not sure what else to check without going back into the motor. 1969 Nova 454/M21/3.31 Mild mid-11 second weekend cruiser 1994 F150 XLT Super Cab 2WD 5.0/4R70W/3.55 (Daily driver)

Re: Would the XE256 cause an E58 to have low vacuum? [Re: 69L78Nova] #427779 08/05/09 07:05 AM 08/05/09 07:05 AM
Joined: Jan 2003 Posts: 16,123 Grand Haven, MI patrick I Live Here
patrick I Live Here Joined: Jan 2003 Posts: 16,123 Grand Haven, MI	the only additional info I can add, is when I initially put together my 360 with the comp XE262, I had an eddy performer 750. it ran like a scalded cat above 3k RPM, but I could never quite tune the low RPM bog out of it, and my car felt kinda soft on the low end, it wouldn't light the tires up romping on it, you'd have to deliberately powerbrake it. I switched to an eddie performer 600, and I gained a ton of low RPM responsiveness, as well as 2" idle vaccuum. stomp on the gas and the rear would light up and start to walk out on you, and if I did lose any high RPM performance, it wasn't noticable. the huge neutral-drive RPM drop you mentioned initially makes me think there's still something wrong with the timing, or possibly with the torque converter, but I suppose it could be carb tuning. when you were messing with and checking the timing, you did have the vaccuum advance disconnected and plugged, right? Last edited by patrick; 08/05/09 07:06 AM. 1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod SOLD!* 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)

Re: Would the XE256 cause an E58 to have low vacuum? UP [Re: 69L78Nova] #427780 08/05/09 07:24 AM 08/05/09 07:24 AM
Joined: Jan 2003 Posts: 5,443 Indiana Y YO7_A66 master
YO7_A66 master Y Joined: Jan 2003 Posts: 5,443 Indiana	""The timing is set at 12* initial, and the idle is set at 1100 in park/neutral, but it drops down to about 550 in gear. Vacuum in park is about 16-17, and in gear drops down to about 11-12"" Since your timing at 1100 N is 12 degrees is the same as the timing in gear, then this might be a carb idle circuit problem which might indicate that the carb is lean in D. (I wonder if your springs are fluttering in D which would make it rich?) Try tuning the carb once you have the motor up to running temp and since it is an auto, then tune the car with the tranny in D and the emergency brake applied. Then you can readjust the carb for the highest vacuum while in D at the desired rpm. Tuning an auto car for best vacuum while in N is fine to get you close, but an auto street driven car needs to have the final tuning done while in D with the brake applied to simulate actual driving conditions. Note: I have had 6 carbs on my 340 and the worse performing carb by far was the Edy Performer 750. The Edy Performer 600 was a much better idler/performer carb. 1970 YO7 A66 [Canadian Export] F8 Challenger 340 (Currently in shop for stroker assy.)

Would the XE256 cause an E58 to have low vacuum? update [Re: YO7_A66] #427781 10/23/09 09:27 PM 10/23/09 09:27 PM
Joined: Apr 2007 Posts: 2,327 Glendale, AZ 6 69L78Nova OP Banned. Forever.
69L78Nova OP Banned. Forever. 6 Joined: Apr 2007 Posts: 2,327 Glendale, AZ	I know Im bringing this thread back from the dead, but I have been messing with this car off and on for a while now. I have done a compression test, and all cylinders are averaging 135 across all eight. Squirting oil in the cylinders doesnt make any difference at all. I also swapped intake manifolds from the stock cast iron TQ manifold to a Performer for testing purposes. The vacuum is still what I consider low, but rock steady (16-17 in park at 1000rpm, and 12-13 in gear at 600rpm) I degreed the cam and it is in at 106*, which is what Comp says. I changed the converter and now its stalling at 1600 all the time. This motor has all of about 4000 miles on it, and has never smoked or had one bit of blowby. I cant understand why the compression test would turn up such low numbers. The only thing I can think is the cam. Ive been looking at some of Summits cam and lifter kits. I have heard many good things about them for the price. I am not looking to build a racecar out of this boat, but I would like to have some low end torque since 99% of the driving I do is city. I dont want to start throwing parts at it, but since the Summit cams have a fairly good reputation for what they are...would the K6900 or K6901 be a better choice for a heavy car like this? 1969 Nova 454/M21/3.31 Mild mid-11 second weekend cruiser 1994 F150 XLT Super Cab 2WD 5.0/4R70W/3.55 (Daily driver)

Re: Would the XE256 cause an E58 to have low vacuum? update [Re: 69L78Nova] #427782 10/23/09 09:37 PM 10/23/09 09:37 PM
Joined: Mar 2005 Posts: 3,138 Central NC gch master
gch master Joined: Mar 2005 Posts: 3,138 Central NC	Have you tried another carb? My only other suggestion would be to advance the cam 2-4 degrees and see if it likes it.

Re: Would the XE256 cause an E58 to have low vacuum? update [Re: gch] #427783 10/23/09 09:45 PM 10/23/09 09:45 PM
Joined: Apr 2007 Posts: 2,327 Glendale, AZ 6 69L78Nova OP Banned. Forever.
69L78Nova OP Banned. Forever. 6 Joined: Apr 2007 Posts: 2,327 Glendale, AZ	Ive had 3 different carbs on it. 2 Thermoquads, and one 600 Edelbrock. The Edelbrock did have a bit more low end and pulled maybe 1" of vacuum more than the Thermoquads. Also, I forgot to add...I did advance the cam 2* to 104 and the only thing it did was kill my gas mileage. Im drawing a blank here 1969 Nova 454/M21/3.31 Mild mid-11 second weekend cruiser 1994 F150 XLT Super Cab 2WD 5.0/4R70W/3.55 (Daily driver)

Re: Would the XE256 cause an E58 to have low vacuum? update [Re: gch] #427784 10/23/09 09:47 PM 10/23/09 09:47 PM
Joined: Apr 2005 Posts: 12,271 Overpriced Housing Central RobX4406 I Live Here
RobX4406 I Live Here Joined: Apr 2005 Posts: 12,271 Overpriced Housing Central	Something is VERY wrong. Did you fix or check the balancer issue? There is NO REASON that camshaft shouldn't idle at 750-850 rpm with a 50-75 rpm drop in gear. If the timing is correct, I bet there's a vacuum leak somewhere.

Re: Would the XE256 cause an E58 to have low vacuum? update [Re: RobX4406] #427785 10/23/09 09:59 PM 10/23/09 09:59 PM
Joined: Apr 2007 Posts: 2,327 Glendale, AZ 6 69L78Nova OP Banned. Forever.
69L78Nova OP Banned. Forever. 6 Joined: Apr 2007 Posts: 2,327 Glendale, AZ	Where could a vacuum leak be though? I changed the carb, the manifold, and it dies when you choke it. Im not sure how a vacuum leak would cause such low numbers on a compression test either. Unless thats all a sub-8.0:1 with this cam will do. Could this cam bleed off enough cylinder pressure to do that based on the specs of the cam? 1969 Nova 454/M21/3.31 Mild mid-11 second weekend cruiser 1994 F150 XLT Super Cab 2WD 5.0/4R70W/3.55 (Daily driver)

Re: Would the XE256 cause an E58 to have low vacuum? update [Re: 69L78Nova] #427786 10/24/09 12:37 AM 10/24/09 12:37 AM
Joined: Jan 2005 Posts: 12,419 Kalispell Mt. H HotRodDave I Live Here
HotRodDave I Live Here H Joined: Jan 2005 Posts: 12,419 Kalispell Mt.	Your compression does not sound bad, your motor is very low compression ratio and will not pump up big numbers unless you put something with VERY short .050 duratio in it. I had a stock cam from a 273 2bbl in my 318 with 10.0 compression and it pulled 20 inches vaccume so your vaccume is not the end of the world. I think your carb or ignition is the problem I am not causing global warming, I am just trying to hold off a impending Ice Age!

Re: Would the XE256 cause an E58 to have low vacuum? update [Re: HotRodDave] #427787 10/24/09 12:55 AM 10/24/09 12:55 AM
Joined: Jan 2005 Posts: 12,419 Kalispell Mt. H HotRodDave I Live Here
HotRodDave I Live Here H Joined: Jan 2005 Posts: 12,419 Kalispell Mt.	Reading back over every thing it looks like your distributer is advancing too fast anmd probably too much. That motor will want a lot of initial advance like 18 degrees minimum, of course now it will run like crap if you do that because it is advancing it too much too early. You need to take apart the distributer and put stiffer springs in it. Also can probably put in a shorter advance plate so you get less total witch since you are advancing the initial will really keep the total about the same. Your motor will want a lot of initial but not too much total like mabey 36-38 total. If you do tha math you start with 38 and subtract 18 for the initial you have 20 left you need to get mechanically so you plate should say 10 degrees on it witch will give you 20 degrees at the crank. You need tight springs so it don't start advancing until 1000 and max out at about 2000-2200. You need to put the distributer to rest once and for all and eliminate it as the problem. After that you can move on to a carb problem. Your motor will probably end up makeing more vacume than any of those carbs were desighned to handle so the idle circuits will need some modifying. I noticed my motor always wanted more fuel at idle than the carter carbs both TQs and AFBs would give it. Don't give up though they can be fixed but eliminate the distributers timing curve first. I am not causing global warming, I am just trying to hold off a impending Ice Age!

Re: Would the XE256 cause an E58 to have low vacuum? update [Re: 69L78Nova] #427788 10/24/09 08:09 AM 10/24/09 08:09 AM
Joined: Dec 2004 Posts: 1,061 New Mexico D dmerc super stock
dmerc super stock D Joined: Dec 2004 Posts: 1,061 New Mexico	Why not leave the timing where it ran best (advanced) and put in a good strong mini starter to get it started?? I had a stock starter on my 408 and it just wouldn't start. Put a mini starter in and voila! no problem!

Re: Would the XE256 cause an E58 to have low vacuum? update [Re: dmerc] #427789 10/24/09 09:10 AM 10/24/09 09:10 AM
Joined: Feb 2003 Posts: 12,675 Columbia, CT M moper I Live Here
moper I Live Here M Joined: Feb 2003 Posts: 12,675 Columbia, CT	Low compression readings can also come from a weak starting system. Are the cables new? Battery the biggest you can fit? I havent used a factory old-type starter in 10 years. The remans are terrible in most cases so I either get a used factory Magnum one or buy the brand new MP unit. You will not have to buy another one once you do that. I also think you need to verify TDC because it sounds like the balancer is junk. At least make a single mark over the inner ring, rubber, and outer ring and see if it's moving around at all after driving it hard. That cam should have another 5-8� at idle and idle speed should be down near 650. I think perhaps the lean burn Thermoquad carb needs some work too to run properly. Well, art is art, isn't it? Still, on the other hand, water is water! And east is east and west is west and if you take cranberries and stew them like applesauce they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know.

Re: Would the XE256 cause an E58 to have low vacuum? update [Re: moper] #427790 10/24/09 11:16 AM 10/24/09 11:16 AM
Joined: Apr 2007 Posts: 2,327 Glendale, AZ 6 69L78Nova OP Banned. Forever.
69L78Nova OP Banned. Forever. 6 Joined: Apr 2007 Posts: 2,327 Glendale, AZ	Wow, thanks for all of the replies! It looks like I have some tuning to do. I called Comp, and they also said this cam should have way more vacuum than this. So the plate in the distributor will actually have a number on it as stated above? I have a box of distributors up in the crawlspace that I can search through. Can I use two factory stiff springs, or are those too strong? As far as the battery goes, it is a 6 month old group 27, and the starter is the longer factory style starter that was in my 11.2:1 360 in my Barracuda for a while. Im gonna go out and mess with that ignition timing and see what I can come up with 1969 Nova 454/M21/3.31 Mild mid-11 second weekend cruiser 1994 F150 XLT Super Cab 2WD 5.0/4R70W/3.55 (Daily driver)

No low end torque [Re: patrick] #427791 02/24/10 10:06 PM 02/24/10 10:06 PM
Joined: Aug 2008 Posts: 25 TX 6 68 Dart GTS member
68 Dart GTS member 6 Joined: Aug 2008 Posts: 25 TX	Patrick and Mopart guys, i'm having the same no low end torque problem also. I have a 68 dart 383. It is pretty much stock but bored 30 over, schumacher headers, 383 torker mainifold with a new holley 770 avenger carb, new Comp. XE274 cam and lifters, stock heads ported and polished with HD springs, new pushrods, rebuilt 727 trans, 323 sure grip and 3000 hughes stall converter, stock elct. ignition with orange ECU box. Everything is pretty much new in the motor compressions good, vac.is good but it's totally a dog on the low end out of the hole. the motor runs great and it seems to make good power but it just seems like its not getting the power to the rear wheels at launch. I'm starting to think the new in the box stall converter which i bought from a friend may be clogged or have trash in it. Any suggestions would greatly be appreciated. I have gotten pretty frustrated and don't want to just throw more money at it and hope the problem gets solved. Thanks.

Re: Would the XE256 cause an E58 to have low vacuum? [Re: patrick] #427792 02/24/10 10:18 PM 02/24/10 10:18 PM
Joined: Aug 2008 Posts: 25 TX 6 68 Dart GTS member
68 Dart GTS member 6 Joined: Aug 2008 Posts: 25 TX	Patrick and Mopart guys, i'm having the same no low end torque problem also. I have a 68 dart 383. It is pretty much stock but bored 30 over, schumacher headers, 383 torker mainifold with a new holley 770 avenger carb, new Comp. XE274 cam and lifters, stock heads ported and polished with HD springs, new pushrods, rebuilt 727 trans, 323 sure grip and 3000 hughes stall converter, stock elct. ignition with orange ECU box. Everything is pretty much new in the motor compressions good, vac.is good but it's totally a dog on the low end out of the hole. the motor runs great and it seems to make good power but it just seems like its not getting the power to the rear wheels at launch. I'm starting to think the new in the box stall converter which i bought from a friend may be clogged or have trash in it. Any suggestions would greatly be appreciated. I have gotten pretty frustrated and don't want to just throw more money at it and hope the problem gets solved. Thanks.

Re: No low end torque [Re: 68 Dart GTS] #427793 02/24/10 10:19 PM 02/24/10 10:19 PM
Joined: Apr 2007 Posts: 2,327 Glendale, AZ 6 69L78Nova OP Banned. Forever.
69L78Nova OP Banned. Forever. 6 Joined: Apr 2007 Posts: 2,327 Glendale, AZ	Mine ended up being the carb 1969 Nova 454/M21/3.31 Mild mid-11 second weekend cruiser 1994 F150 XLT Super Cab 2WD 5.0/4R70W/3.55 (Daily driver)

Re: Would the XE256 cause an E58 to have low vacuum? update [Re: 69L78Nova] #427794 02/24/10 10:22 PM 02/24/10 10:22 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Quote: So the plate in the distributor will actually have a number on it as stated above? Can I use two factory stiff springs, or are those too strong? (1) yes (in dist degrees) (2) yes too strong, the stiff factory spring w the long loop, toss it & keep the light oe spring and add another one (not sure what is available) 5828479-distslot002.jpg (99 downloads) live every 24 hour block of time like it's your last day on earth

Re: Would the XE256 cause an E58 to have low vacuum? update [Re: RapidRobert] #427795 02/24/10 10:26 PM 02/24/10 10:26 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Here's a chart 5828485-dirstspringcurves.jpg (132 downloads) live every 24 hour block of time like it's your last day on earth

Re: No low end torque [Re: 69L78Nova] #427796 02/24/10 10:28 PM 02/24/10 10:28 PM
Joined: Aug 2008 Posts: 25 TX 6 68 Dart GTS member
68 Dart GTS member 6 Joined: Aug 2008 Posts: 25 TX	yea i pulled the edelbrock perf. carb. 650 off my brothers 68 cuda and it made minimal difference. I have a new aveng. 770 holley on it now with hardly any changes in the low end.

Re: Would the XE256 cause an E58 to have low vacuum? [Re: 68 Dart GTS] #427797 02/24/10 10:37 PM 02/24/10 10:37 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Quote: Patrick and Mopart guys, i'm having the same no low end torque problem also. what is your compression/vacuum and initial live every 24 hour block of time like it's your last day on earth

Re: Would the XE256 cause an E58 to have low vacuum? [Re: RapidRobert] #427798 02/24/10 11:17 PM 02/24/10 11:17 PM
Joined: Aug 2008 Posts: 25 TX 6 68 Dart GTS member
68 Dart GTS member 6 Joined: Aug 2008 Posts: 25 TX	approx. 9.5-1 to 10-1 comp. 12 degrees intl. and 14 vac.

Re: Would the XE256 cause an E58 to have low vacuum? [Re: 68 Dart GTS] #427799 02/24/10 11:24 PM 02/24/10 11:24 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	the initial & vac sound good. Do you know what your cranking compression is? EDIT Probably more inportant than the CC, I missed the 3.23's which are hurting you and what is your curve Last edited by RapidRobert; 02/24/10 11:27 PM. live every 24 hour block of time like it's your last day on earth

Re: Would the XE256 cause an E58 to have low vacuum? [Re: RapidRobert] #427800 02/25/10 12:12 AM 02/25/10 12:12 AM
Joined: Aug 2008 Posts: 25 TX 6 68 Dart GTS member
68 Dart GTS member 6 Joined: Aug 2008 Posts: 25 TX	yea i know the 323 gears are hurting some, but this little A-body should still be launching pretty hard. Got buddys with 383 roadrunners with 323 gears and there launches are very stout compared to this A-body.

Re: Would the XE256 cause an E58 to have low vacuum? [Re: 68 Dart GTS] #427801 02/25/10 12:22 AM 02/25/10 12:22 AM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Quote: Got buddys with 383 roadrunners with 323 gears and there launches are very stout compared to this A-body. Point taken. Alright I'd do a compression test (I believe in the basics) and post your curve (total/all in @what rpm) what do the plugs show? EDIT I reread your post and I'm thinking more initial and shorten the slots to maintain 36-38 total (checked w vac adv disconnected/hose plugged)& what springs are in there(if a stock heavy one w the long loop is, it needs to go) Last edited by RapidRobert; 02/25/10 12:46 AM. live every 24 hour block of time like it's your last day on earth

No low end Torque on 383 Dart [Re: RapidRobert] #427802 02/25/10 12:37 AM 02/25/10 12:37 AM
Joined: Aug 2008 Posts: 25 TX 6 68 Dart GTS member
68 Dart GTS member 6 Joined: Aug 2008 Posts: 25 TX	Thanks for you help, We have gone through alot of things on this with alot of hard work and no results, i have a lokar cable system for the throttle and kick down and have looked at that also due to kick down issues. I'll just keep plugging away on this, i really thinks it's something real simple that i;m overlooking. thanks again.

Re: No low end Torque on 383 Dart [Re: 68 Dart GTS] #427803 02/25/10 12:50 AM 02/25/10 12:50 AM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	It's a good thing the chebby/furd guys dont have our dedication and support system . when you find it be sure and post it live every 24 hour block of time like it's your last day on earth

Re: Would the XE256 cause an E58 to have low vacuum? [Re: 68 Dart GTS] #427804 02/25/10 11:16 AM 02/25/10 11:16 AM
Joined: Jan 2003 Posts: 16,123 Grand Haven, MI patrick I Live Here
patrick I Live Here Joined: Jan 2003 Posts: 16,123 Grand Haven, MI	Quote: approx. 9.5-1 to 10-1 comp. 12 degrees intl. and 14 vac. is that verified or what the pistons are supposed to give? KB flat tops at 0 deck, steel shim head gasket, and OEM 906 heads usually only yields 9:1....if they are stock type replacement pistons in the hole, you're probably in the low-mid 8's at best. what's your cranking compression in PSI? initial with that cam, assuming actual compression is in the 8's, I'd run about 18-20. if your cranking compression comes in low (under 150), I'd seriously consider dropping in cam size a bit (lunati voodoo 60302 is what I'd pick), or opening up the motor and advancing installed centerline of the cam 4-6 degrees to close the intake valve sooner to gain cranking compression. the torker is also a mediocre intake...especially if you're looking for "street" performance... http://hotrod.automotive.com/62106/hrdp-0712-mopar-intake-manifold-comparo/edelbrock-383.html check out the torque figures at 3000 RPM...it's down 25 lb-ft from a weiand action plus, or eddie performer, and most likely a stock intake. 1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod SOLD!* 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)

Re: Would the XE256 cause an E58 to have low vacuum? [Re: patrick] #427805 02/25/10 12:10 PM 02/25/10 12:10 PM
Joined: Jan 2003 Posts: 2,931 P Paul_Fancsali master
Paul_Fancsali master P Joined: Jan 2003 Posts: 2,931	The comp you have is fine with that motor its actually pretty good. The problem is not initial its total get tha low comp up timing wise and and forget the 36 total crap Mopar preaches,The 36 toatl is for 9-10-11 one comp not some lean burn cast off 360. Try to find a Accell dual point dist put it in stock and set the total starting at 44 degree's, and try it you will love the way it performs provided everything else is up to snuff/ put a 650 dbl pumper on it and go have fun. Insist on TQ then tighten up the air valve so that it will not just flop open like the factory settings with the old weak sec springs that it probably has in it. By the way oif this combo is wrong then guess what I'd rather be wrong and fast then right and slow

Re: Would the XE256 cause an E58 to have low vacuum? update [Re: RobX4406] #427806 02/25/10 04:53 PM 02/25/10 04:53 PM
Joined: Jan 2003 Posts: 6,840 The Swamp S Sixpak master
Sixpak master S Joined: Jan 2003 Posts: 6,840 The Swamp	Quote: Something is VERY wrong. Did you fix or check the balancer issue? There is NO REASON that camshaft shouldn't idle at 750-850 rpm with a 50-75 rpm drop in gear. If the timing is correct, I bet there's a vacuum leak somewhere. Start with the BASICS - make sure the timing mark on the balancer is not off. Do you know how to use a positive stop tool against the piston to determine if the timing marks are off? If the balancer mark is on, is the oil pump drive properly indexed to the # 1 cylinder when the motor is at TDC? Where is the cam installed - straight up, advanced, or retarded? Do you have adjustable rockers - if so, are they adjusted properly? Can you block off all other vacuum hoses and outlets on the manifold except for the vacuum gauge and the vacuum advance for the car, to eliminate all other sources of vacuum leaks? Can you borrow a known good working carb from someone to test with? Has anyone fooled with the advance curve or changed the springs or weights in the distributor? Does the vac advance unit have a leak? Does it hold a vacuum?

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