car won't 60 foot video

https://www.youtube.com/watch?v=b2gEtOJ4Qdo

472, powerglide, ladder bars,tryed a 5000 stall convertor and 5800. Tire pressure is 7psi. Tryed leavin at 3000, 4000, 4800 and 5000 with very little change. Once the car is in high gear its on. Looking for suggestions. Thanks. Birdtracker

What rpm r u leaving off the t-brake. Seems flat.

What shocks... it does seem very flat like the
power isnt there.. whats your timing at

timing is 36, distrubutor is locked. I tryed leaving from an idle, 3000, 4000, 4,800 and 5000. something is amiss thanks. Birdtracker

Looks to me like it's dead hooking and bogging it down.

It just looks like the motor is numb at the hit.
What are the 60' times anyway?
ET & speed?

Timing, jetting, float level, cam size, low gear ratio, etc...... Could be any of those things or more.

Converter way too tight

I had a 5,000 stall convertor in it, and put a 5800 and the 60 foot didn't change. 1.65. Will run very consistant 6.55s in the 1/8 at 119. Plan on going to Norwalk just to experiment. Birdtracker

What motor/cam/carb?

472, 690 Comp roller, and 1050 Dominator. I started with 92 squared jets and went to 97. Back to 93 front and 94 rears. I have not tryed a different carb. It starts great when cold, 2 pumps and fires right up, when hot it takes awhile of cranking but starts. Birdtracker

Mph looks high for the time. Looks like the cam is retarded. Converter to tight. What gear? How tall a tire? When does it go into high? 472, wedge or Hemi? 3.90 or 4.15 crank? If Hemi that could be your problem, needs more gear. All a guess until more info.

wedge 3.92, 14X32 and 4:10s. Birdtracker

It looks to me like the sprag in the converter may be wounded, no torque multiplication.
Doug

4.10 is a low gear to work with a glide. 4.56 would be much better for a mid to high 9 second car.

could trans low gear clutches gone away,,

Needs 4.88s

Minimum, could go 5.12 if just running eights. You don't have the hp to run 4.10s

Two things come to mind on this, is the shifter adjusted so it is in first only? The second thing is the reaction shaft is loose in the converter from the front pump. My car had that happen last year and again this weekend, I think The car lost a bunch of ET and MPH all of a sudden after stumbling on the line and looseing a bunch of 60 ft
Let us know what you find, I've seen several cars leave like that when the shifter cable wasn't adjusted so the pin on the cable would slide in and out of the shifter arm in first gear, the shifter arm would move a little bit when you pulled the cable end pin out of the arm I've seen the same thing on torqueflytes, there leaving in two gears, not worth a hoot

Needs 4.88's and a custom converter. Ever dynoed the engine and optimized the tune?

32" tire, powerglide...that thing needs a lot more gear than 4.10. We've run up to a 5.43 gear in the Camaro w/ a 29.5x10.5 tire and a 1.76 glide. Just running 1/8 mile though.
I agree w/ the others and use a 4.88.

Yup, not enough gear for starters.

IMO, unless the motor is at least an honest 13.5:1cr, both the comp .690 and .692 rollers have too much duration for that combo.
And even at 13.5:1, I think for 1/8 mile racing especially, something shorter would be quicker.

The other thought I had was to try and verify you're getting a good clean release in the trans when you let go of the button.
If the 60' times are about the same when footbraking it, that would tell you the brake is releasing fully.

X2 on that cam, when I had a 3.9 stroke combo I switched from that comp .690 which is 287 @ .050 to a custom comp which was 276 @ .050 and picked up 2 tenths. I ran a 31" tire with 4.56's also.

The 119 mph shows your making power. The converter might be the issue but you said you have try'd two. That MPH should be in the 1.20s sixty foot. The 1.76 glide is killing your sixty.

Yep, needs a little wheel speed.

What's the weight? First off I would lay off the burnout. Mickey's don't need it. I'm not convinced you need that much more gear. I wouldn't go more than .88's personally. I still don't think the gear is your issue. I would take the timing to 38 and see if there is any change.

I tryed a 4:86 gear at the beginning of last year. It was screaming before the 1/8 mile. I do run some 1/4 mile such as Norwalk this weekend. I degreed the cam in and know its in at 106 unless something moved when I slide the gear drive cover on. I can check that. I was going to try timing this weekend and maybe a different carb. Thanks for all the suggestions. Birdtracker

What size dominator is it............My bad just saw 1050......

Screaming? Mine was going 125 mph at 6100 with a 4.56 and 33 " tire, driveshaft speed, 5800. 60 was 1.2. Something might be amiss in the trans or converter.

1/8 mile

I agree, that thing should be able to pull a 4.88 in the 1/4 with 32" tires no problem.

9.97 @ 135 mph. 6,500 trap speed. 14 x 32 4.56 gears.

I guess maybe we need to backtrack a bit......
What is the motor build like? Compression, heads, intake, headers, etc?
What does the car weigh?
What do you expect it to run in the 1/8 and 1/4?

Heck I ran 5.13's for a while with that cam....7400 thru the traps......1/4 mile also.

https://www.youtube.com/watch?v=H7NWfO---hE
here is a video that shows the tach over on the left. Leaving at 5,000. It doesn't rpm like I would expect. Birdtracker

What was that 60 cos it seems to lay down then pick up...........

https://www.youtube.com/watch?v=G-tCIRJH9p0

From the last video I'd recommend trying different gear ratio.

Post the timeslip let us look at the increments

Must be the motor build and car weight are top secret.

If that mph is right the car has decent power. Big block A-body..........so what? 3000lbs. If that is accurate, for that mph, 700ish horsepower. HP based on the ET and weight would be 150 or so less. So the car is WAY down on power early. General consensus here is add gear and while that may help, the problem appears that the converter is way wrong or broken. 4.10 is enough gear. May not be optimal, but it's enough for this car to 60 way better than it does

Must be rather lite, all that aluminum inside, did you see the in car video?

I have only ever run 727 boxes so not familiar with powerglides. What is the ratio of 1st gear in powerglide compared to 727 ???

Its not top secret. I have been out loading for Norwalk. The car is 2550 with me in it. I named it Anorexic. I thought the 4:10 should pull it with the 1.76 first gear.If you watch the first video once it gets to the 1/8 and gets in high gear it flys. I have tryed 2 brand new convertors. One was 5,000 the other 5,800. The 5,800 is whats in it for this weekend. It has 6 passes on it.For this weekeng I am going to look at timing and carb. If I don't find anything then a gear change will happen. I will post some time slips from Norwalk. I am predicting 6.55 in the 1/8. It is very consistant. Birdtracker

Have you confirmed these converters... have you run them up
on the trans brake with no chip in it

What's your valve lash set at?

valve lash is .022 cold. Both convertors flash what they should.I also had the trans out this spring and had it gone thru at a trans shop. New transmission lines and cooler. Birdtracker

Still no motor info.

For a comparison......a friends S/G Cuda from about 10-12 years ago.
2700lbs, 4.88's, 15x33's, glide, 1.76 low, 451 low deck, std port stage 6 heads, tg4500 intake, 1200 carb, 2 1/8 x 4 headers, UD 280/685 roller....... Motor dynoed 650hp.
Went 9.30's at 143. My recollection is that the 60' times were in the high 1.20's.

So I ASSume it around a .028 hot cam? I run mine at .014 cold and end up around .020........this is about WAY more than lash cos something is amiss here big time...........

Cam too much duration for cubes and not enough gear...a 470 cube big block with a 287 @ .050 cam, you better have good heads and spin it to 7500 plus.. I think the 119 was a typo....

Why? We used to run 452 inches with unported heads and the old .750 roller and didn't have to spin them 7500 to make power. But I doubt the motor is the issue with this car.

If and I repeat IF the 119 is not a typo, at 2550 pounds, this thing makes 650ish on HP, which is not tough for an alum headed 470 if it has decent parts. That said, you should be able to kick it off the line and make it 60ft harder than it is, even with 4.10s and a 1.76 glide. I think the converter is way out in left field

I agree Monte, he's using converters for heavy cars (3000-3400 lbs) not the light car he has because it looks like it locking up right off the line. usally what works for a heavy car won't work for a lite car, especially a glide.

Two brand new converters, one 5000 and the other 5800, has tried leaving at numerous different RPM's........ While it certainly could be a converter issue, it would seem as though this has been ruled out.
I still say a footbrake launch might prove interesting...... Besides being easy and basically free.

A tale of two cars, 68 dart 440-727-9" vert, 3200 lb loaded, car left good, wheels in the air ran 6.80 in the eight. 86 Daytona 2500 lb loaded same engine-trans combo out of Dart. Best was 6.55, left like a turtle. Had converter made (same flash) for car then ran 6.08 best.

It really acts like the cam timing is retarted... soft
on the bottom end then starts to turn on up in the revs

The op can confirm or deny this, but here's how I see it played out;
Build car/motor, buy a new 5000 stall converter for the combination, go to the track, car won't leave. Calls a few people, a few people see the car run..... the consencus is the converter is wrong for the combo.
Get new 5800 stall converter built, car runs the same.

Since he says the car pulls hard after shifting into high, my feeling is the trans is bound up in low gear.

I had a trans brake solinoid quit working. I rolled in deep staged and foot braked it, Average 60 foots are 1.65. It was 1.74 on that pass. That was at Nationl Trail at this years spring race. With average 60 fts of 1.65 if it would go 1.30 or 1.20 or 1.18 I would know I solved my problem.
So if I pulled all the plugs out of it so it would roll over, Take the lash out of the #1 intake, put a degree wheel back on the front of the motor, and check .050 before and after with a dial indicator that would tell me cam degrees. I did this with the heads off when I put the motor together. Also I think it would start hard with the cam retarded. Thanks for the suggestions. Birdtracker

How about a compression test just to see what kind of cranking pressure it has.

Is the assumption correct that both of these converters were built for this specific combination?
If so, I don't see how they could get it so wrong....... Twice.

At 119 mph in the 1/8th, leaving like a pooch that tells me this car is making a lot of power, just not much till the Rs get up over 6500 with that cam? My guess is the REAL 1/8th mile per hour would be 121 if it got moving better early. That would be about a 5.75 in the 1/8th, or 9.0 in the 1/4. The 4.10 gear gives you a SLR of 7.40, and I would think it needs more like 9 or higher for decent results. However, it sounds like it is all three issues pointed out. Not enough gear, wrong converter, and a very big cam for that motor and trans combo.
If it were my car, I would borrow a much shorter cam, somewhere around 280/288/110 like my Isky RR735, get a converter built to stall 6500, and put a 4.88 gear in it.

"Very big cam"............Really Greg, cmon now. That's not a big cam at all for a nearly 500 inch motor that apparently makes decent power

There is no motor into other than the cubes and the cam.
It could be a 10.5:1 motor with unported 516 heads, or a 15:1 B1 motor.
Without knowing what the build is, it's certainly possible the cam is too big, which is why I suggested a compression test. If it pumps 125-150, the cam is too big. If it's 190-220, it's not the problem.

Essentially no useful motor info has been provided, nor has it been confirmed whether or not the two new converters were actually built for this particular combo, or if they were simply "new".

IMO, not enough pertinent info has been provided about the overall combo to make a real recommendation.

In any case, he said he was going to Norwalk this weekend, so I'm sure he'll get plenty of suggestions there.

I am only going by the fact he says it goes 119. Even at the light weight, 119 in the 1/8 with a horrible 60ft means it makes some steam

Yep, and they would go 6.50's....

Check the video where he's starting it, a Lot of drag at first, timing, compression or bad starter? Never could see the tach during first gear. He needs to put in low, engage trans brake then floor it to see how high that converter goes.
At 119 mph with that tire and 4.10 gear he's only turning 5040 rpm, drive shaft speed, who knows what the engines turning.

Something is goofy and that didn't look like no 119 run to me and when I paused the vid I thought I saw a faint 105-109 mph.........

So that would mean even less rpm at the stripe.

Watch the vid and freeze it at the end then you tell me..........Birdcatcher needs to fill in the blanks like requested ie; Comp, cam, heads etc............

Time slip people should be posting Time Slips if there isn't a time slip it didn't happen.. the increments are very important

I agree and it seems odd he wouldn't want to help figure out what's REALLY happening so I`m done here.............

We might not be telling him what he wants to hear.
Birdcatcher, there are some very smart guys on here, only trying to help you. No one is trying to put you down, they want to see this car run good, just like you do.

My guess is he's just doing the Norwalk thing right now.
In an earlier post he said he'd post some slips from there, so we'll just wait and see what they look like.

I have had dealings with him in the past and he is a straight shooter.. but Time Slips and engine combination.. all that stuff is very very important I run a Glide behind a small block leaves like a rape ape so if it will run 119 it's got the ability to leave real hard

I watched it run at
Norwalk today. Bogged and ran 125 mph in the 1/4.

What was the et

I wonder if any updates from the Norwalk outing will be forthcoming.......

Lets see if this works.


Birdtracker

I'm not qualified as an expert by no means but my 3000lbs Duster w/small block has gone 1.40 60ft @ 4000DA. I vote convertor.

so here is my weekend in a nutshell. I got there friday at 10:00 a.m and missed #1 qualifying pass. I seen a good racer friend who loaned me a 1150 dominator to try. So on my first pass friday afternoon it went 10.66 but still bogged real bad. So I put my 1050 carb back on Saturday morning and it went 10.41. We only got 1 time run. Went up for round one and went to leave, the car bogged and died without moving out of the beams. Other guy redlighted so I won that round. Went back up for round two and went red. I hesitated at first about running it out thats why it went a 10.50. I ran a qualifying pass on sunday and went .004 red in round one. I put it away and brought it home in one piece. So now I have a cracked header tube and also a small stress crack near the shock tower.

That's not a bad weekend. It's still running and looked pretty consistent for as wide a weather swing as it saw.

I had a really long weekend. I helped 2 other people run their cars also, towing up to the lanes, cooling down, getting the dew off the windows. We got done with saturday night race at 1:00 a.m sunday morning. Birdtracker

so first things first, I am going back to square one. Compression test, then recheck cam timing. I am going after why it has a bog. I will let you know what I find. Birdtracker

Jet extensions?

absolutely. Birdtracker

I'm going to have to say the converter is too tight or broken... you are over 2 tenths off in the 60-foot.. your mph is on par with my old smb it would run 10 flat. With a 1.33 60ft. .it would stall to 6700.and I would shift at about 7700 rpm

since I have had this issue I have 2nd guessed everything and double and even triple check stuff. Then recheck what I checked. I pitted at the end of the track and after slowing would shut the car off and coast to my pit. I took all the plugs out and looked at the color to make sure it wasn't lean which it is not. I put a compression gauge in 5 different cylinders there. 3 on one side and 2 on the other.70 psi was the highest. So I just went out tonight and did a compression test with the carb wide open using 3 different gauges that I checked to my air compressor which shuts off at 120.
#1-50 #2-40
#3-70 #4-70
#5-65 #6-50
#7-40 #8-70

I am depressed. Birdtracker

Motor is 14.8-1 and I run it on C-16. It had 235 passes on it when it was torn down and new aluminum rods installed. So tomorrow night its either leakdown test or cam timing. I am now suprised it ran with that low of compression Birdtracker

Wow, are there rings on those Pistons? Seriously, check the cam again, I was 2 1/2 times that with a 7.90 lift cam and 15.19 cp. Do the leak down first. What type rings.

I thought it should be around 180. The rings are Childs and Albert Moly file fit. I did them. I did look around my garage to see if I forgot!!! So on leakdowns that I have done it takes the piston to be at the top to have both valves closed. I may have to ensure valves are closed and piston maybe not all the way up? Birdtracker

Piston all the way up and locked so it won't move with the air pressure, on the firing stroke, no valve should be open at that point. Listen to where the air goes, intake, exhaust or crankcase. You don't want to hear it come out the in-ex, bad, bad.

Is your dampener marked every ninety degrees? If so bring #1 on the firing stroke at TDC and check it, move the crank 90 degrees clockwise and check #8 and then work your way down the rest of the firing order Let us know what you find
Some of these dang motor gremlins can drive us absolutely nuts If you never make a mistake racing you ain't doing enough

Is there a lot of blowby? If not I don't think a leak down test will tell you anything. Those compression readings can't be right. I don't know of any engines that will even fire at 40-70 psi. It would have to sound like its just spinning with the plugs out. Too consistent for there to be any single cylinder issue, which means there has to be something common among all cylinders. Camshaft installed wrong is most likely suspect. Or all of the pistons are way below deck.

X2

Double check CP test again I don't see how it could have ran that MPH with no compression

its the cam...seen compression like that many times. there isn't enough swept vol. for a 3.90 stroke to have those duration numbers unless he has a 48-52cc chamber. When I ran that cam with a 3.90 stroke I had 58cc heads and ran 110 Torco. Happens when you choose way too big of a cam. The combo here would probably run ok on 86 octane an 40 degrees of timing. What cylinder head cc are we looking at here? If its in the 70's you need some thing with 258-264 @ .050 intake to get going...especially with a 4.10 gear and big tires.

I'm gonna say if the compression tester gauge has been confirmed to be (at least reasonably) accurate, it's likely got bent valves.

Just remembered reading this...235 runs then new rods. Where they the same size? Anything else changed? What where the times before these changes? Did you run this engine before the changes? Did you just buy it ?

[quote=birdtracker]Motor is 14.8-1 and I run it on C-16. It had 235 passes on it when it was torn down and new aluminum rods installed. So tomorrow night its either leakdown test or cam timing. I am now suprised it ran with that low of compression Birdtracker [/quote

235 passes, what did it used to run in the beginning? Was is quicker, actual 119 1/8? That low compression it appears the cam is in way late.
Doug

One of my lawn tractors has about 60psi of cranking compression. It starts just fine. You need a surprisingly little amount of compression to get an engine to run.

As others have mentioned, check valve timing, that the valves themselves aren't slightly bent, etc.

so I just came in from the garage. I went ahead and pulled the radiator, fan, alternator and lower crank pulley. I installed the degree wheel so 0 lined up with the TDC pointer. I pulled the drivers side valve cover off and went to put my dial indicator on and the clamp that adjusts broken in 5 pieces. So I will need to pick up new dial indicator base and need to put my hands on a leakdown tester. Thanks for getting me headed in the right direction. Birdtracker

One more thing, make sure the tdc pointer is on true top center first. I made a stop to go in the spark plug hole and touch the piston, rotate both ways and mark, split the difference and bingo, right on.

Birdtrack, could you answer a few of the questions put to you ? See DVW's last post.

x2, too much dwell at tdc, and not enough known accuracy in pointer to be trusted.

The cam would have to be a few teeth off for the comp test to go from what it should be, down to 70-80psi. It's down 100psi for what it should be.

^^^^^^^^^This right here. Even if you did NOT degree cam and just lined the dots up, it would NOT be down 100lbs. If you missed it a tooth it would NOT be down 100lbs. So the cam is either WAY off, or it has bent valves. If it had this much blowby, it would smoke.

If you look back on the first page, he says a couple things of merit. Says he has a gear drive and that he did degree it in on 106. Now some gear drives can be a little tricky if you are not positive of what all the numbers mean, but he says he DID degree it and it was right, so it seems he knows how to read a degree wheel. Second thing he says is that it is hard to start when hot. Has to wind a lot. Low pumping pounds would definitely do this. He has stated valve lash, so it would not seem valve lash is tight, plus he says it starts better cold. Tight lash would be opposite..............

so the magic number is 122 and 1/2. So now I got to figure how to get it back in. Guess I am taking the rocker arms off and the access cover on the gear drive.Rocker arms are piece of cake but to get to the gear drive the motor plates and water pump have to come off. Should the cam need rotated clockwise or counterclockwise? Like I said thanks for the direction. Birdtracker

I am thinking one tooth and turn it clockwise.What a pain. Birdtracker

2nd lobe back is intake.

I degree'd in the exhaust once lol.

I'm not sure what the tooth count is on a gear drive, but on a normal double roller set up 1 tooth is 14deg.
Going from 122 to 106 isn't going to pick up 100psi cranking pressure.

Of the timing sets I've come across in the last 30 years, I have encountered 3 where the dot on the upper gear was on the wrong tooth.
These were all found on customers motors that were already running, that the owners had installed cams in, lined up the dots, and the motors seemed to be down on power.
All 3 had the cam retarded a tooth because of the mis-stamped upper gear.
All of these motors ran well, but had cranking pressures lower than expected.
They were all like 10:1 street/strip deals and instead of having the expected 150-160psi on the gauge they were more like 120.

I don't feel a 14.6:1 motor is going to lose 100psi on a compression test by advancing the cam 16deg...... But I guess we'll see.

How did the cam to from being degreed in at 106 to now being in at 122?

I think when I stuck the cover on the intermediate gear, it spun the cam. Thats the only thing that makes since. So I got all the front torn down. If I take the intake off and pull the valley tray, I can check all my lifters, plus pull the cam straight out and turn and go back in. My cam gear has 52 teeth. Got to be an equasion to figure out if its one or two teeth.All the valves open and close as they should. I also thought if a valve was bent I think there would be 0 compression on that cylinder. But I have had bad experiences when I think! Birdtracker

I dynoed a SBC dirt modified motor for a customer a few years ago.
They had been running the car for several events but it just wasnt competitive, so they brought it in to have it tested to see how it stacked up.
It ran beautifully, sounded real good, and had pretty good throttle response...... But it was way way down on power...... Like 100hp or so.
These are pretty bread and butter combinations. If you use A,B,C, and put it together right they all make about the same power. Something has to be pretty screwed up to be off 100hp.
I suspected the cam was in wrong, but the builder(whom I'd worked with quite a bit over the years) assured it was degreed in properly.
"Normal" cranking pressure for these is over 200psi.
I tested one cylinder quick and it was only like 150-160.
After some discussion and exchange of ideas, I tested a few more cyls.
The pressures were all over the place. A couple close to 200, a few down near 100.
I leaked it down........ It had a bunch of bent valves.

Took the motor off the dyno and they took it home. They pulled it apart, and after disassembling the heads found almost all the valves were bent. Some a little, some a bit more.

They can run just fine with bent valves....... But they won't make any power with bent valves.

I will say this, If I hadn't tested that motor myself and saw how good it ran, I never would have believed it could have run so good with the valves so screwed up.

Depending on how tight the piston to valve is on this motor, the cam being off 14* could cause it to kiss some valves.

We broke a pushrod on the 738 once in the burnout and it killed the motor. Went back to pits, fixed the pushrod, fired the motor, it ran like ass and couldn't figure out why. As Fast described, we did a compression check and they were everywhere. Pulled the heads and all the valves were bent slightly......but why? When it broke the pushrod, it caught under a rocker, stopped the cam and jumped the belt drive a tooth. Took the gear off, lined cam back up, touched up the valves and were racing in a few hours. Did all this at the track

On all my gear drives and even chain stuff I set the
TDC first and put on the pointer and wheel... then set
the crank at 106(where it says intake C/L) then roll the
#1 INTAKE lifter at peak lift.. then see if the gear will
slide on EASY... then do the .050 before and after to check...
I havent looked at dots in years after I had a MP one 23* off

360 degrees divided by 52 is 6.923. So each tooth is almost 7 degrees. Advancing it 2 teeth should put it at 108.5. Then leak it.
Doug

Thanks Doug. I need to take the intake off tonight. Birdtracker

That would be 6.9 at the cam right? The crank spins twice as fast so it would be 13.8 at the crank per tooth on the cam gear would it not?

Yep

I was thinking the same thing.
I wouldn't think it's all that easy to get 14:1+ compression out of a 470 without some head milling, and with that Comp .690 cam I can't imagine there was a big surplus of piston to valve clearance on the exhaust side, even with the cam installed at the correct c/l.
With it in at 122, i would think some contact could easily happen.

so I pulled my intake, valley cover, rockers, push rods, and all the roller lifters. The good news all the pushrods are straight and all the lifters are as should be. I paint marked the cam gear and pulled the cam completely out of the engine. All the lobes look good so I reinstalled it one tooth. Will recheck cam centerline tomorrow. So I looked at all the valves and springs. They are all the same height. After degreeing its getting a leakdown this weekend. I am down to the heads any ways so if I gotta take them off now is the time. Birdtracker

Don't need a cam in it to leak it down.

For what you're looking to determine....if the valves are tweaked or not......it doesn't even need to be at tdc. Just hook up the tester and pump some air in and see what the leak % is. If it's pretty high, see of it's blowing by the valves.
The air will push the pistons down if you're not at tdc, but it won't really matter for this test(with the valvetrain not functioning).

I looked up the specs for the .690 cam lobes.
Looks like they move the lifters about .004"/degree at around the tdc mark.
I would have installed that cam at 104 and checked my p/v clearance there, and possibly made a slight adjustment to the installed position if it would have solved a p/v clearance issue.

The cam was supposedly in at 122 now, which is 18deg retarded from where I would consider the "normal" installed position. .004 x 18 = .072, x 1.5 rockers = .108.
So, you lost roughly .100" p/v clearance on the exhaust by having the cam in at 122.
I hope you had a lot to spare.

Fast 68: we are going to find out. The car is pretty light so 106 0r 108 would make me happy. Birdtracker

I guess my point was, I would have figured in a fairly normal build, that cam installed at a pretty normal installed c/l would have only had about .150" or so exhaust p/v clearance.
If you back the cam up 14-18 deg from there you lose .80-.100" of that clearance..... And that's when valves start tagging pistons.
Everyone has their own process of working things out, but IMO, a leak down test should be close to the top of the list of the next steps taken.

I would at least put compressed air in each cylinder and listen/look for leaks at the header. If it bent any of the valves (which I have a hard time thinking 18 degrees retarded couldn't, and which brings up other thoughts if it didn't) it would be the exhaust.

I would say it's pretty much a sure thing the valves are bent. Because as already discussed, 14* of cam timing will not have the pumping pounds down 100psi from where it should be

Monte, that's my feeling as well..... But "never say never"

"If" the ex valves aren't tweaked(and that's a big if), then moving the cam a tooth with get the intake c/l close to where it should be...... And then the cranking pressure would be whatever it is.
It's not going to gain 100psi, but at least you'd know what that number was.
That being said, as I mentioned before ....... I feel you'd need at least 180psi cranking pressure to really make good use of that cam. If it's only 140-160 or so(without bent valves), then I'd probably look at installing something a little shorter.

But, I think the results of a leak down test would point the direction on what to do next.

Edit: I just used the Wallace cranking compression calculator.
A 14:1 470 with a 287@ .050 cam in at 108 should pump 181psi at sea level.
Move the cam to 122 and it drops to 126psi, so a 55psi difference.

What #`s do you come up w/Fast on my 12.1.1 470 w/276-281@ .050 in at 105 at 2500-3000 ft elevation.............thankxxx..........

Or not............. I`ll figure it out.........

It's one of the Wallace on line calculators........punch in the numbers..... See the results.

I found it but need my cam card for opening/closing events so I`ll dig it up later just got a grip of carbs...........

so one tooth brought it in to 108. Thats the only good news. I installed 100 psi on the leak down and it only has 80 on the other side. Pretty much all the valves are bent. Thanks for all the help. Birdtracker

Honestly....... That's 20% leakage....... I would have thought it would be worse than that.

Did it seem like there was a lot of air going by the exhaust valves?

Sorry to hear this man but maybe you can get some better valves w/a nice back cut and rock n roll unless you already have good ones............

I agree if you have bent valves it would be pouring out the exhaust...I my experiences highly audible/noticeable.

Many times when there is light contact between the valves and pistons, with the valves hitting the pockets nice and square, it will barely tweak them..... To the point where you can't even see it, but they leak. When you reface them you notice they have been tweaked.

Apparently there was quite a bit of p/v clearance, otherwise it should have tagged them harder, which would mean a higher leakage %.

Just cuz I'm curious, I would have stuck a pair of lifters and rockers back on it and done a compression test on a couple cyls........ Just to see.

Take heads off, poor gas in chamber. If it leaks past valves you have trouble, if not then your ok

Rubbing Alcohol is better, with some red food coloring.

Setting the input pressure at 100 and getting 80 lbs on the outlet calculates to be 20 % leakage, not good but not horible either Where the pistons at TDC? If not redo them with the pistons at TDC and see what you get I have seen over 6% differences on the same cylinder when leaking them cold by slightlly rocking the crank 1 to 3 degrees either way Another way to verify the sealing on the valves is to pop the top of the valves so they open a little bit under pressure with a soft blow hammer when the air is in the cylinder I've seen a gain on the readings that way also Same thing on a cold leakdown and then retesting it with the motor warmed up If you get it to test better than 12% I would run it until you can get the motor out and check the ringlands to ring side clearances and see if the ring ends show signs of butting