another 3.79 vs 4.00 vs 4.125 sb stroke comparisons

Posted By: 1967dartgt

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/07/13 10:10 PM

How long is the GV unit? Would you get in to driveshaft angle problems on a A body .

Posted By: MR_P_BODY

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/07/13 10:17 PM

Quote:

How long is the GV unit? Would you get in to driveshaft angle problems on a A body .

Its only like 6" long and the angle hasnt been a issue...
plenty of the DW guys run the GV... my 518 is probably
a bit longer than the 727 and GV... but when I set
up the engine and trans in the Rampage I set it so
it was pointed straight at the pinion then rolled
in the pinion angle

Posted By: mopar dave

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/07/13 10:58 PM

4.100 might be pushing it on the bore with that stroke. I was thinking 4.040 bore for strength and .060 over would be max. i'd like to get some input on this topic from someone who has tried these different crank combos on a dyno or at the track to get some more real world info. don't want to spend a bunch of money on extra machine work to only find out it runs no better than my currnet 408. Andy, you out there? any other engine builders that can add to this?

Posted By: B3422W5

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/08/13 12:54 AM

Personally, with the heads you have, or W5 heads like I ran, I think the 4 inch crank is plenty, and well suited to both making power, torque, and longetivity, and reliability.
Bigger the bore the better. I also like the longer rod, ran a 6.300 rod.
At 4.100 bore the CP domes were only a hair over 400 grams.
Bumping your compression up like you are talking about with a 4 inch stroke and correct matching components will make more than plenty of torque to make your car 60 foot plenty good.
I know it can be done. I would strongly suggest a better block than you are using so you can reliably run a bigger bore, sticking with your current stroke,and calling Dwayne Porter and having him spec you out the proper roller cam once you get a good shortblock put together.

Posted By: 1967dartgt

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/08/13 05:49 AM

I used to run a 4.09 bore and a 4 in crank in a stock block with a .620 roller and 12 to 1 compression with Indy 245 heads. It went 9.90s on motor and lived many years.

Posted By: mopster

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/08/13 08:59 AM

With 3.79" stroke your rpm range will be about 350 higher, and with 4.125" stroke 200 lower. What is best for you depends what rpm range works best with the rest of the combination. Your chassis and the track you race has also a great meaning to this. If you can handle more torque without hooking issues you will most likely be faster with more sroke, assuming the rest of the combination is optimized for that stroke. However, the difference might not be much, and your money could be better invested in somewhere else.

Posted By: Raymond

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/08/13 02:07 PM

I have the 3.79 with the 6.4 rods in a w5
motor. N/A the motor made about 700 h.p.
Now with a single turbo it dynoed at 1027 rwhp.
If you are interested i have two sets of mahle
power pack flat top piston for this combo.

Posted By: DJVCuda

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/08/13 02:12 PM

While I was building my 4.125 striker a guy copied my recipe of one of the milder versions and we compared dyno sheets. This was same top end and cam but 4" vs 4.125

Bottom line the 4.125 made more hp & tq and it made it earlier, longer and seemed to win all around.

If I remember correct as I don't have the info available right now it was about 20 & 20 hp& tq difference.

544 & 566 are coming to mind on the hp levels but that's about all I can recall at this point.

Posted By: mopar dave

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/08/13 04:20 PM

that sounds like a good combo with 700hp using the 3.79 crank n/a. whats your bore size and what block?
it would take aleast 20hp/tq to make me move away from my current 4" crank.
peak hp is now at 6600, so another 350 wouldn't be a problem.
i'm not a racer, just go to the track a few times per year to play and see what i'v accomplished. get about 100 street miles per year lately.

Posted By: mopster

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/08/13 04:56 PM

Going for shorter stroke is a wrong move unless you race in a bad track and you have trouble hooking. If you are looking for more power, playing with different strokes and rod ratios isn�t going to do the trick. Keep the 4" stroke and use the money to increase the airflow and you will be much happier.

Posted By: mshred

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/08/13 05:00 PM

Quote:

Going for shorter stroke is a wrong move unless you race in a bad track and you have trouble hooking. If you are looking for more power, playing with different strokes and rod ratios isn�t going to do the trick. Keep the 4" stroke and use the money to increase the airflow and you will be much happier.

I don't know alot, but I would have to agree with this. In fact, I would be more inclined to go up in stroke instead of down if for nothing other then the extra torque it would create and at less rpm (better longevity of valvetrain parts), but the rest of the setup would have to be optimized.

I think a compression bump with what you already have would work out well

Posted By: mopar dave

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/08/13 05:04 PM

I think the car hooks great. could use a double adjustable on the rear to improve 60' abit. It seems the 408 isn't making enough power to move the car for better ET's. car weights 3300 and runs 10.35@130. I estimate 580-600hp off motor.
one reason I believe this is just by changing ignition box from a Mallory hifire6 to an Ice 7amp box and coil, 60' went from a 1.52 to mid 1.4's.

Posted By: MR_P_BODY

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/08/13 05:26 PM

Quote:

I think the car hooks great. could use a double adjustable on the rear to improve 60' abit. It seems the 408 isn't making enough power to move the car for better ET's. car weights 3300 and runs [Email]10.35@130.[/Email] I estimate 580-600hp off motor.
one reason I believe this is just by changing ignition box from a Mallory hifire6 to an Ice 7amp box and coil, 60' went from a 1.52 to mid 1.4's.

If you change just the ignition box and you picked
up that much you had a major problem in the ignition
but your 60' is still off(slow) based on the ET & MPH

Posted By: mopar dave

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/08/13 05:39 PM

yeah, that's why I believe it could use some better shocks. i'v got a ton of vids and the tire is not spinning. the vert works good, it falls back about 700rpm on the shift. sometimes I wonder if something is binding or rubbing together in the trans. been temped to call up john cope and get a brand new 727 from him.
anyway, I do believe the Ice ignitions are something to look at over msd, Mallory for sure as i'v had a bunch.

Posted By: MR_P_BODY

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/08/13 05:48 PM

Quote:

yeah, that's why I believe it could use some better shocks. i'v got a ton of vids and the tire is not spinning. the vert works good, it falls back about 700rpm on the shift. sometimes I wonder if something is binding or rubbing together in the trans. been temped to call up john cope and get a brand new 727 from him.
anyway, I do believe the Ice ignitions are something to look at over msd, Mallory for sure as i'v had a bunch.

I had a Mallory ignition when I first built my car...
that lasted 2 weeks... when I called them they gave
me a bunch of BS and that I was using it in the
wrong environment... as in a race car.... they said
they would fix it for a cost.... I trashed it and
moved on.... as for the trans.. I dont know but the
MPH is there so to me its making the power(and getting
it through the trans)... if it were not the MPH would
be down

Posted By: mopar dave

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/08/13 05:56 PM

yeah mike, but it seems like the combo should be more like 625-650hp with what I have. I agree with the Mallory stuff. i'v had a earley hifire box that broke me down twice a Mallory fuel pump that gave me fits a Mallory unilight that the bushings wore out in no time flat, so I understand where your coming from. I thought the hifire6 was a nice box with a lot of features,guess not. my worst box was a msd digital6. I still have a Jacobs that works great.

Posted By: MR_P_BODY

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/08/13 06:01 PM

Quote:

yeah mike, but it seems like the combo should be more like 625-650hp with what I have. I agree with the Mallory stuff. i'v had a earley hifire box that broke me down twice a Mallory fuel pump that gave me fits a Mallory unilight that the bushings wore out in no time flat, so I understand where your coming from. I thought the hifire6 was a nice box with a lot of features,guess not. my worst box was a msd digital6. I still have a Jacobs that works great.

I have hear more people with problems with the digital 6
boxes than ones that didnt... I wont buy one for that
reason

Posted By: b1dartsport

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/08/13 06:31 PM

If you are interested in getting to the other end of the track the quickest and want to continue to use your 360-2 230 cc Indys, there was a combo that was well documented on here and was the fastest 230 cc combo I have ever seen or heard about. I believe the car was an early 70s dart swinger owned by John Pennington. It had a 4.07 bore,Scat 4" crank, Eagle 6.123 H beams,stock block,nothing trick about the short block at all. (no chevy rods,light weight pins or trick ring pack) The heads had 2.15 Ferea intake valves installed and valve job and port and chamber work to take advantage of the larger valves. It had an Indy intake that was port matched and had some minor plenum mods. The cam was an Indy spec cam 279/279 @.50 .680/.680 108 LSA installed at 108. Chambers were 63cc and compression was at 13.5 with an off the shelf piston. Off the shelf wet sump oil pan,vacuum pump,1000 Race Demon Carb,2" Hedman Husler headers,727 with a mid 5000 converter. At 3100# this combo went 9.20s to 9.30s at more than 142 mph. I saw this car run in 2005 and still have not heard of any Indy 360-2 230 that was faster at that weight. As said before I think you would be better off staying with the 4" crank,more compression and focusing on getting the head and cam combo to work better.

Posted By: mopar dave

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/08/13 06:47 PM

very impressive. who did the heads? my indys are 360-1 ported to 230, so I have the square ports.

Posted By: b1dartsport

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/08/13 08:21 PM

I believe the heads were done at a ford shop near John Pennington's home. This combo was freshened by Ryan Johnson at Shadydell speed shop and he posted the combo on here. Ryan was surprised how simple this motor was and how much HP it produced on his Dyno which was a very conservative 670 HP. I think what this shows you that if you pay attention to details,(Heads,Cam) and get the rings to seal well you can make big HP. I believe that Ryan has been doing the 2.15" intake on some of the Indy engines he has been building and likes this head mod.-Randy

Posted By: mopar dave

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/09/13 12:30 AM

i'll see if I can find that old thread. sounds interesting.

Posted By: b1dartsport

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/09/13 03:02 AM

Dave,If you are still searching for that post I think the title by Ryan was " Most powerful 59* Motor Ever?" or something along those lines.

Posted By: B3422W5

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/09/13 04:06 AM

Quote:

Quote:

I think the car hooks great. could use a double adjustable on the rear to improve 60' abit. It seems the 408 isn't making enough power to move the car for better ET's. car weights 3300 and runs [Email]10.35@130.[/Email] I estimate 580-600hp off motor.
one reason I believe this is just by changing ignition box from a Mallory hifire6 to an Ice 7amp box and coil, 60' went from a 1.52 to mid 1.4's.

If you change just the ignition box and you picked
up that much you had a major problem in the ignition
but your 60' is still off(slow) based on the ET & MPH

Exactly.... Ignition in working order over another in working order should basically result in little to nothing difference in ET or 60 foot either one.

Posted By: B3422W5

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/09/13 04:19 AM

Quote:

yeah mike, but it seems like the combo should be more like 625-650hp with what I have. I agree with the Mallory stuff. i'v had a earley hifire box that broke me down twice a Mallory fuel pump that gave me fits a Mallory unilight that the bushings wore out in no time flat, so I understand where your coming from. I thought the hifire6 was a nice box with a lot of features,guess not. my worst box was a msd digital6. I still have a Jacobs that works great.

With the dinky 260@ 50 cam your running and just over 11 to 1 compression your not gonna come close to making 650 horse with that combo. Sorry, but just telling you the truth.
You know my d combo, which I figure made an honest 650 running at your weight or a hair more. It was about 5 tenths and 5 mph quicker than you are . So a very big difference from where your at.
If you are really looking to make power, you need to really step things up in the camshaft and compression departments, assuming the heads are real good.
Otherwise your just nibbling at the edges of truly stepping things up and improving your ET.
It can make that power and still see street duty( drove mine way more than 100 miles a summer) you just need to decide on what you want the car to run and use parts that will allow it to do so.

Posted By: mopar dave

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/09/13 05:36 AM

yeah, I know. the 260 cam is in their to match the 11:1 compression and I did make improvements in ET going that route. 2 tenths improvement. the next combo will obviously get a bigger cam to match the 13:1+ compression. ran a best of 10.35@130 and 10.39@131. this thread was started to just get some direction on next combo with this block. the results of the leak down test shows I can run this combo another season, but it will have huslers a vacuum pump and a davinci dominator and I may have sanchez take a look at the heads for the next combo though.

Posted By: mopar dave

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/09/13 03:01 PM

found the thread. thanks

Posted By: B3422W5

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/09/13 04:30 PM

Dave, I think your car runs extremely good. Think you have maximized your combo and it runs as well as it should.
You should be proud of the numbers it lays down

Posted By: mopar dave

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/09/13 05:58 PM

well thanks, but the problem is i'm never really happy. I will go another season with pump gas with a few add ons. maybe I can lose a couple more tenths maybe not, but I want to see what it will do on pump gas first. end of next season i'll be looking at a race gas combo and that is the point of this thread. looks like i'll stay with the 4" with 13-13.5:1 and light parts. i'll have the heads looked at buy a mopar professional. can ya suggest a good mopar cylinder head shop?

Posted By: B3422W5

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/09/13 06:31 PM

Quote:

well thanks, but the problem is i'm never really happy. I will go another season with pump gas with a few add ons. maybe I can lose a couple more tenths maybe not, but I want to see what it will do on pump gas first. end of next season i'll be looking at a race gas combo and that is the point of this thread. looks like i'll stay with the 4" with 13-13.5:1 and light parts. i'll have the heads looked at buy a mopar professional. can ya suggest a good mopar cylinder head shop?

I would suggest Jerry Arnold here in Kalamazoo. He is a former national record holder in comp, and is mighty handy( and reasonable) porting heads, and setting them up, etc.
I know he did Al's heads( the yellow Duster that has the same heads as yours and has run 9.60's)
Definitely would be a guy I would highly recommend.

http://www.arnoldcylinderheads.com/about.shtml

Posted By: mopar dave

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/09/13 06:51 PM

ok, thanks

Posted By: mopar dave

Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons - 12/09/13 08:03 PM

heres another. Steve Clukey's 414 built with an X block, indy heads and intake, dominator. sure would like to know his combo756hp/611tq
http://www.youtube.com/watch?v=5vMv5zjW9oI

another 3.79 vs 4.00 vs 4.125 sb stroke comparisons