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 Street/Strip Boosted 71 T37 w/70 GTO tribute
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Corncob2061
Crazy Horse

USA
535 Posts

Posted - 08 Aug 2019 :  11:53:09 AM  Show Profile  Reply with Quote
Over the weekend we made some major progress on our modification efforts for our 71 T37. I started a thread last fall for this on PY on the boost forum. I will add to the PY thread as I go but I like the editing features over here on PSP. So this is a coffee shop thread for this build, for thoughts, thinking out loud, other opinions A-Z for this creation we are working on. Jay

PY thread I started:
http://forums.maxperformanceinc.com/forums/showthread.php?t=822970

Edited by - Corncob2061 on 08 Aug 2019 1:40:52 PM

67drake
Sitting Duck

Azerbaijan
1544 Posts

Posted - 08 Aug 2019 :  12:03:51 PM  Show Profile  Reply with Quote
Sounds Cool! I never go into the turbo area on PY, so I would have never read it.


71' GTO Original 400 M20 3.23 posi
13.95@102.1 MPH on street tires
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Corncob2061
Crazy Horse

USA
535 Posts

Posted - 08 Aug 2019 :  12:09:20 PM  Show Profile  Reply with Quote
The t37 had the original suspension and 8.2 rear end under it. Drum brakes, no anti sway bars, ect, ect.. We have the front clip off, engine and trans out. We have the interior pulled getting ready to do a roller bar. The biggest tire we will put on the car is what is considered small tire for some racing classes. But the new suspension I believe would hold its own on a road course. I will get some pictures up when we get the body nestled down on the new frame.

Starting to make plans for this engine. Probably looking at 1000 hp max using a 1960 389. There are several of us working on this car now. My brother and two friend stepped up and have been a bunch of help. I am going to start with the engine plans and work my way around the car. Engine will be the next post. Jay

Edited by - Corncob2061 on 08 Aug 2019 1:42:38 PM
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Corncob2061
Crazy Horse

USA
535 Posts

Posted - 08 Aug 2019 :  2:13:05 PM  Show Profile  Reply with Quote
For those that do not know much about the 59-60 389s, they are a breed of their own. They have thick cylinder walls, some can be bored as far as 4.25, lol, that?s .188 over. They have some block reinforcement the later block do not have. They also have no provision for a starter on the block, and their own bell housing pattern. We are using a mid plate, which is also the trans adapter, then the starter mounts to the mid plate.

This is a 3.75 stroke E85 flex fuel build. The heads are d port 96d, exhuast ports are enlarged to RAIV size. Right now it has 2.11/1.77 stock length valve. Ported slightly under 270 cfm on the intake, exhaust has mild porting and flow 200s. We may change the intake seat angle to 45 because the cam we are running is really aggressive on the intensity. I am doing a search for pistons. The heads are cut down to 87 cc, probably be down to 86cc by the time the machine shop redoes the finish for the cometic head gaskets. Shooting for 8.7-9 SCR. The cam is a CompCam Max area solid flat tappet. 283/291 256/264 .050 with compcams emd oiling on the lifter. The cam is 112 lsa, planning on degreeing it in on 107 ICL. With a 1.7 ratio the total lift is .580.In the realm of .560 accounting for the lash. We were going to try a solid roller, going to start with this cam. The head bolt fasteners are arp studs and we are using Cometic head gaskets.

Edited by - Corncob2061 on 09 Aug 2019 5:21:34 PM
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Steve C.
Chief PONTIAC

2054 Posts

Posted - 08 Aug 2019 :  3:36:24 PM  Show Profile  Reply with Quote
Reading over the PY post.

A fwiw, my last forged crank from SCAT checked out fine.

In the dark ages I ran a 9.59 with a M/T true 10.5/28" slick. Your tire size should be ok, the radial racing guys today have no issue. Obvious if you chassis set up is right!
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Corncob2061
Crazy Horse

USA
535 Posts

Posted - 08 Aug 2019 :  3:59:50 PM  Show Profile  Reply with Quote
We started out thinking 4 inch stroke. But decided with the small tires we would have better results with a 3.75 stroke. Unfortunately the only one that makes a forged crank for the 3.75 is Ohio crankshaft. Which I think will be ok.

Steve what do you think you were pushing for hp too run that 9.59 in your car? Jay
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Steve C.
Chief PONTIAC

2054 Posts

Posted - 08 Aug 2019 :  4:53:45 PM  Show Profile  Reply with Quote
It was this combination. On the dyno it made 699.9 hp at 6900/7000 rpm with a Victor/Dominator carb. But I ran it with a regular Victor intake and 'worked' HP950 carb. About 20 hp less. It was the only engine we tried nitrous with, a simple plate system. So long ago I do not remember the tune, maybe a "250" shot, give or take. Ran it for a year with very much concern for how much the factory block would take. Retired it and moved the rotating assembly to a IA2 block and put it into John's Fairmont.

http://www.pontiacstreetperformance.com/psp/racerSC01.html

Big difference in my leafspring set up than your GTO. That and the turbo will be much different than hitting it with nitrous.


Edit: I just noted the error in that link. The 699 hp was not with the Carb Shop 750, as stated here it was with a Dominator carb. The Carb Shop 750 made 680 hp on the dyno. But soon after I changed to worked HP950 carb. Brad Urban rated that Stage III Holley 750 at 926 cfm.

Edited by - Steve C. on 08 Aug 2019 5:13:38 PM
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Corncob2061
Crazy Horse

USA
535 Posts

Posted - 09 Aug 2019 :  5:20:34 PM  Show Profile  Reply with Quote
That was getting close to 1000hp then, 900 for sure. I did not notice it listed on the build, was it running splay main caps? Guessing it had to be to survive that. Jay


Edited by - Corncob2061 on 09 Aug 2019 5:32:58 PM
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Steve C.
Chief PONTIAC

2054 Posts

Posted - 09 Aug 2019 :  8:09:17 PM  Show Profile  Reply with Quote
Not splayed. Pro-Gram Engineering steel main caps- rear, front and center caps. With ARP stud kit.
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Corncob2061
Crazy Horse

USA
535 Posts

Posted - 10 Aug 2019 :  12:32:13 AM  Show Profile  Reply with Quote
I was wondering about that, I was thinking all the 70 400s and 455s were drilled for 4 bolts mains even though most did not use them.

We have a 71 455 that has been drilled for 4 bolt mains we have been talking about using it as a spare engine. The Program engineering mains caps and backing the stroke down and using a Scat 4 inch crank would be a good start. Jay
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Corncob2061
Crazy Horse

USA
535 Posts

Posted - 10 Aug 2019 :  01:59:56 AM  Show Profile  Reply with Quote
I will admit it has been hard to let go the IDEA of doing the 4 inch stroke in the 389. If anything just to keep the rpms down some. Does not appear on dyno sims that the extra stroke will do us much good. Appears roughly 7000 rpm will be max power with the 3.75 crank...jay

Edited by - Corncob2061 on 10 Aug 2019 02:52:40 AM
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Steve C.
Chief PONTIAC

2054 Posts

Posted - 10 Aug 2019 :  09:16:57 AM  Show Profile  Reply with Quote
From a previous post quite some time ago. Even though you plan on a short stroke it's something to consider for conversation. Comments plagiarized from the internet regarding a 4.500" aftermarket crank in a factory block.......

Caps are not expensive, but the machine work is and will cost you $1000 total ( or more).
If you plan to build any type of serious power, the center three main caps (No. 2, 3 and 4) should be changed out to steel caps. No real need to change the front and rear caps unless the originals were damaged. Naturally, if budget is not an issue, the best approach is to change out all five caps for aftermarket steel). Purchase a center cap set from Pro-Gram Engineering. The caps, as delivered, are slightly undersized (by about 0.0025) requiring align-boring and honing for your desired clearance and main bore alignment. While OE main bore diameter is specified at 3.438, cut the OE front and rear caps (to allow a fresh bore size/alignment) and final-honed our mains at 3.4387 ( the bore a tad looser when using a longer stroke crank). Also, the thrust bearing is featured on the No. 4 cap. Pro-Gram raw-machines the thrust relief in this cap, requiring the final thrust bearing relief to be done on the block, after align honing. When the Pontiac blocks were machined at the factory, the caps were secured in place, with main boring and thrust-face machining performed as an assembly. As a result, you cant simply install a finished replacement cap, because you'll never match-up to the original indexing. Install caps, align-bored and honed the main bore, and then fly-cut the thrust faces on the No. 4 cap flush to the thrust faces on the block saddles. The caps secured with new ARP main studs.

Also note the dowel pins used to align the main caps are like fingerprints- no two are exactly alike. My suggestion would be to buy and install oversize dowels to ensure a tight fit. (I have always bought mine from Paul Spotts if memory serves me right or maybe Butler)



.

Edited by - Steve C. on 10 Aug 2019 09:40:58 AM
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Steve C.
Chief PONTIAC

2054 Posts

Posted - 10 Aug 2019 :  09:39:48 AM  Show Profile  Reply with Quote
More from previous posts that may or may not apply. This regarding the thrust cap. On the 455 block Pro Gram Engineering leaves .020" on the thrust cap for finish. That may not be the situation on a 400 block, but I cannot recall now. I've had the three center plus front and rear caps installed on both a 400 and 455 blocks.

I would highly recommend Pro-Gram Engineering main caps. They are out of business but their website will direct you to where they are now offered. My stud kits always came from ARP.

Also I will highly recommend the block fill material called Block Rock sold by Race Engineering. Fast set up time and no need to vibrate block. Block machinable in 24 hours. Will not crack or separate with age.
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Corncob2061
Crazy Horse

USA
535 Posts

Posted - 10 Aug 2019 :  11:34:47 AM  Show Profile  Reply with Quote
Good info! I will check out Block Rock. I forgot Pro gram went out of business, I thought I noticed Butler had them listed in their sight yet last week.

Here is one dyno sim from the other day with twin turbokenetics HP76s on the 389 with 18 lbs boost, 8.7 scr with the MA 283/291 compcam. Sorting stuff out looking for trends, a 4 inch stroke crank adds another 40-50 lbs to the torque numbers, these are for the 3.75...

4000. 679 hp. 892tq
4500. 792 hp 925 tq
5000. 875 hp. 919 tq
5500. 938 hp. 896 tq
6000. 996 hp. 875 tq
6500. 1022 hp. 826 tq
7000. 1016 hp. 736 tq

Edited by - Corncob2061 on 10 Aug 2019 11:37:33 AM
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Steve C.
Chief PONTIAC

2054 Posts

Posted - 10 Aug 2019 :  1:18:53 PM  Show Profile  Reply with Quote
Pro-Gram Engineering is now Billet SpeedWorks

https://billetspeedworks.com/
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Steve C.
Chief PONTIAC

2054 Posts

Posted - 11 Aug 2019 :  2:02:14 PM  Show Profile  Reply with Quote
Opinion. At the proposed power level I'd use a forged crank with either strokes considered.
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Corncob2061
Crazy Horse

USA
535 Posts

Posted - 11 Aug 2019 :  11:51:18 PM  Show Profile  Reply with Quote
Certainly more power than we are comfortable with using a cast crank. I am certain the fatigue would break the cast crank at some point. Since this is a street car we considered using an arma steel crank and changing it out after a certain number of passes. It would probably last a long time if most of the time it was on the street. I have 3 3.75 arma steel cranks laying around. But balancing again and again then changing cranks now that they make forged cranks is probably not the way to go, we need to go forged, balance it once and call it a day.

The rods are a bit of a debate yet, aluminum is temping. Leaning toward a set of eagle with the bolt upgrade. I think eagle rates them for 1500 Hp with the better bolts.

https://www.summitracing.com/parts/esp-6625p3dl19/make/pontiac


Edited by - Corncob2061 on 12 Aug 2019 12:47:52 AM
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beertracker
Cochise

434 Posts

Posted - 18 Aug 2019 :  10:29:47 PM  Show Profile  Reply with Quote
Jay:

Are you building a 1/8 mile strip car?

Gary
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Corncob2061
Crazy Horse

USA
535 Posts

Posted - 18 Aug 2019 :  11:02:46 PM  Show Profile  Reply with Quote
Gary it looks like this car going to be more street than anything at the strip. The two closest tracks are 1/8 mile tracks for us though, so it will definitely go to an 1/8 mile strip. But when we get busy and do not find time to race the strip only cars we have had just sat, this car looks like it will be to much fun to not drive.

My brother and I use to race NHRA and IHRA in the Super Street 10.90 index class, door cars only. We do not have a car anymore for it though. Would be fun to trying to run this car in that. Extremely competitive class these day though, not sure how a turbo car would do. Mainly just planning to take the car local bracket race and special Pontiac or BOP events. Jay

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Corncob2061
Crazy Horse

USA
535 Posts

Posted - 19 Aug 2019 :  12:16:41 AM  Show Profile  Reply with Quote
Really have been hoping a tbfi system would work for this combo, they look simple and are not to much more price wise than a good blow throw carb. Looks like the ceiling for hp for a Holley sniper on e85 would be maxed at 870 HP. Still researching but it appears to be less than Holley rates it for, the fuel map stops at around 16psi boost even though they rate it for more boost than that, it is uncharted on their fuel map from what others have said. I know holley does not rate or recommend it tor e85, but that does not have appeared to stop people. Comparable systems from Fast and FItech run out earlier hp wise and have smaller injectors, 87cc is 760 HP on e85. Realistically a MPFI system is not our budget, unless we get very creative, and build something from one of the retro fit systems. Which might be doable, not something we want to tackle right now though.

Budget wise though, we probably need use a MPFI system and use race gas when at the track if we want to push hp limits and hold the boost down on the street on pump gas. Or on the street back off the boost and run e85, I doubt we would miss the extra hp loss with e85 on the street. Jay

Cheapest fi option appear to be these.
Holley sniper. 8 100lbs injectors. 16 lbs boost is about the most it safely will go off the fuel map.
https://www.summitracing.com/parts/sne-550-512/

Fast Sportsman. 8 74 lbs injectors stock, but it appears 87s will fit. 15 max boost.

https://www.summitracing.com/parts/fst-303001bt/

FI tech system. I think they have 87 lbs injectors too. Appears this system might allow more boost than the others. They claim 25 psi.

https://www.summitracing.com/parts/fif-30012/

Edited by - Corncob2061 on 19 Aug 2019 08:21:01 AM
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