[stuman]

A few months ago, I posted a question on the options I had of increasing the compression ratio of my ’77 Pontiac 400cid to approximately 9:1. I thank you all for your ideas and opinions. The engine is now being machined and will be assembled late summer early fall. One thing I have noticed about this site that the drag racing information is just super plentiful here, but I’m having trouble finding circle track racing information.


Now I have a few more ideas that could use some comments. (AKA: the Pontiac project)

As a hobby I am involved in dirt track racing. The track is a .375 mile medium/high banked black dirt/clay surface and the sanctioning body is IMCA (www.imca.com). After a few years of success, the driver/owner/etc. is considering installing a Pontiac 350cid engine (after I talked him into it). The reason for the 350cid is imca has an engine size limit of 360cid on general motor engines, so no 400’s (also no 400cid parts). Please keep in mind that imca has an engine claim where the top 4 finishers in the feature has a chance that a racer that finished in 5th on back could purchase their engine. (Hobby stock class is $325.00) You will see me try to save every penny at every point in this project.


- Not too much information too early, I need to keep everybody interested.

- The short block-

I would like to leave completely stock (almost used condition). That means maybe polishing the crankshaft, turning it if I have too. New pistons might be too expensive, try to use the existing ones if I can, unless I have to bore the cylinders oversized. New bearings (of course), new oil pump (any affordable high pressure ones available?), timing chain (still looking for information on how to adjust the camshaft degree, Chevrolet no problem Pontiac has a keyway, so I’m assuming an offset key?), new camshaft (this requires its own paragraph), factory windage tray – 1973 style, homemade crank scraper, oil pump pickup will be looked at and modified. Etc. etc. etc.

- The camshaft-

The single most influence on an engine (in my opinion). I have studied a few camshaft choices and will continue to do so. I don’t expect to find the best camshaft first but at the same time I don’t want ten camshafts that didn’t work. Before the engine is completed I see I need to contact some cam grinders.

- Heads-

What we have now (as we only have one 350cid Pontiac engine) are #46 heads w/screw-in studs and guide plates. Damn, already we have a problem, rules state – no porting, no polishing, and no shouldered (big hex on the bottom) screw-in rocker arm studs. The first rules – porting, polishing are no problem, but the rule regarding the rocker arm studs causes some concern. Can we find non-shouldered rocker arm studs? If so can we still use factory guide plates with them, or can a Pontiac push rod survive without guide plates? Back to the number #46, I have not measured them yet, so valve sizes and chamber volumes will be added to this post later, I did see the cylinders are machined to “un shroud� both intake and exhaust valves. Lastly would the #46 head be a good choice or should I be looking in more junkyards for different numbers.

- Intake/Exhaust manifolds-

The intake manifold on this engine is a stock cast iron 2bl with egr provisions. The rules state no porting no polishing, which is not a problem. I see issues when trying to use different intake manifold with different heads so I might have to live with the egr. The manifold seems heavy, has anyone cut the egr passageways off the bottom of the manifold (just to save weight)?

The exhaust manifolds are stock cast iron dual type (the exhaust pipes combined together after the transmission). Rules state the exhaust manifold go with the engine when claimed, so porting polishing cutting and welding is allowed. But with such huge manifolds compared to Chevrolets is anything necessary?

-Quick facts-

• building a Pontiac 350 to test feasibility of use
• .375mi medium banked dirt track
• 3000# car weight w/driver
• currently using a stock (and I mean stock, excluding Cam and springs) Chevrolet 350 engine turning 7000 rpms – will be changing gears to decrease rpm’s an appropriate amount for the Pontiac
• also considering an Oldsmobile (but that’s a different project)
• Can’t wait to see the tech inspectors, or the claiming drivers expecting to see a Chevrolet, ask us what the heck engine is that? Oooohhhhh

THANK YOU FOR YOUR TIME

Lastly – opinions needed…. (And I know everyone has at least one)

[stuman]

A few months ago, I posted a question on the options I had of increasing the compression ratio of my ’77 Pontiac 400cid to approximately 9:1. I thank you all for your ideas and opinions. The engine is now being machined and will be assembled late summer early fall. One thing I have noticed about this site that the drag racing information is just super plentiful here, but I’m having trouble finding circle track racing information.


Now I have a few more ideas that could use some comments. (AKA: the Pontiac project)

As a hobby I am involved in dirt track racing. The track is a .375 mile medium/high banked black dirt/clay surface and the sanctioning body is IMCA (www.imca.com). After a few years of success, the driver/owner/etc. is considering installing a Pontiac 350cid engine (after I talked him into it). The reason for the 350cid is imca has an engine size limit of 360cid on general motor engines, so no 400’s (also no 400cid parts). Please keep in mind that imca has an engine claim where the top 4 finishers in the feature has a chance that a racer that finished in 5th on back could purchase their engine. (Hobby stock class is $325.00) You will see me try to save every penny at every point in this project.


- Not too much information too early, I need to keep everybody interested.

- The short block-

I would like to leave completely stock (almost used condition). That means maybe polishing the crankshaft, turning it if I have too. New pistons might be too expensive, try to use the existing ones if I can, unless I have to bore the cylinders oversized. New bearings (of course), new oil pump (any affordable high pressure ones available?), timing chain (still looking for information on how to adjust the camshaft degree, Chevrolet no problem Pontiac has a keyway, so I’m assuming an offset key?), new camshaft (this requires its own paragraph), factory windage tray – 1973 style, homemade crank scraper, oil pump pickup will be looked at and modified. Etc. etc. etc.

- The camshaft-

The single most influence on an engine (in my opinion). I have studied a few camshaft choices and will continue to do so. I don’t expect to find the best camshaft first but at the same time I don’t want ten camshafts that didn’t work. Before the engine is completed I see I need to contact some cam grinders.

- Heads-

What we have now (as we only have one 350cid Pontiac engine) are #46 heads w/screw-in studs and guide plates. Damn, already we have a problem, rules state – no porting, no polishing, and no shouldered (big hex on the bottom) screw-in rocker arm studs. The first rules – porting, polishing are no problem, but the rule regarding the rocker arm studs causes some concern. Can we find non-shouldered rocker arm studs? If so can we still use factory guide plates with them, or can a Pontiac push rod survive without guide plates? Back to the number #46, I have not measured them yet, so valve sizes and chamber volumes will be added to this post later, I did see the cylinders are machined to “un shroud� both intake and exhaust valves. Lastly would the #46 head be a good choice or should I be looking in more junkyards for different numbers.

- Intake/Exhaust manifolds-

The intake manifold on this engine is a stock cast iron 2bl with egr provisions. The rules state no porting no polishing, which is not a problem. I see issues when trying to use different intake manifold with different heads so I might have to live with the egr. The manifold seems heavy, has anyone cut the egr passageways off the bottom of the manifold (just to save weight)?

The exhaust manifolds are stock cast iron dual type (the exhaust pipes combined together after the transmission). Rules state the exhaust manifold go with the engine when claimed, so porting polishing cutting and welding is allowed. But with such huge manifolds compared to Chevrolets is anything necessary?

-Quick facts-

• building a Pontiac 350 to test feasibility of use
• .375mi medium banked dirt track
• 3000# car weight w/driver
• currently using a stock (and I mean stock, excluding Cam and springs) Chevrolet 350 engine turning 7000 rpms – will be changing gears to decrease rpm’s an appropriate amount for the Pontiac
• also considering an Oldsmobile (but that’s a different project)
• Can’t wait to see the tech inspectors, or the claiming drivers expecting to see a Chevrolet, ask us what the heck engine is that? Oooohhhhh

THANK YOU FOR YOUR TIME

Lastly – opinions needed…. (And I know everyone has at least one)

[johnta1]

Well,I'm not a roundy-round guy,so I don't know if I can help that much.

One of the reasons why I don't like it is some of the reasons you said.
Claiming engines.
Always tearing up your car.
Repairing spindles,wheels,tires,control arms,etc. every race.

The reason for the screw in studs rule is because they make it for the chevy guys.
They don't realize the Pontiacs could be had with screw in studs from the factory.

The log type of exhaust manifolds are really restictive for performance use.
Try to find a 1972 or older manifold.No EGR.
Also 1972 and older 2 bbl heads would be pressed in studs.

I would think the 350 would make some low end torque,so you would have to set the car up for that.(compared to the chevy)

johnta1
Pontiac Power RULES !!!
www.wallaceracing.com

[BigB]

are you allowed to deck the heads, if so that may open up some options for a better flowing head. But some of the better flowing may be too many cc's for the 350, hence the decking.


1974 ventura
455
670 heads
victor
1050 dominator
250hp NOS
Tubbed
Caged
Lots more.

[Steve Barcak]

To answer a few more questions. On Cam, the Ram air IV grind is hard to beat for the dollar. I've bought many of them from Warrior for $65 (they may have gone up a bit, not sure). Of course, check spring height and tension. You may have to change springs/height but, this will bring a lot more mid range (where you need it). this is probably the biggest bang for the buck, so to speak. like John said, use a '72 and older intake but, if you can use the '72 version, it is the only year with out EGR that fits the later heads without a heat crossover problem (if you are unable to get around the screw in stud rule, this probably won't matter but it is good to know about). On your guideplate question yes, you will need to use them with any '67 and later head for stability. Maybe a '68-70 350 small valve head would work for you, it has pressed in studs.
Since you are primarily making left turns, that will be a good thing with the Pontiac. The oil pump on a Pontiac is on the right side so, while making left turns, the oil will stay on that side of the pan. Pay attention to the bearings, you may want to think of something as far as baffling. Also, use a baffeled oil pan.
Degreeing a Pontiac cam is done with offset keys on the cam, crank or both. also, most aftermarket timing set have multiple keyways. I do not suggest advancing the cam as some would on a street car as you are not concerned with power off idle. I'd run it straight up.
definately gear the car accordingly, don't buzz it unless you carry a basket with you. Keep it under 5,500.
Steve www.pontiacheaven.org

[fiedlerh]

I would try to make cheater screw-in studs with the hex machined off, or maybe you can find some that are already made that way. You can mount the gudeplates with two bolts like they are for press-in studs.

Maybe you can convince them that most Pontiac engines came with screw-in studs and therefore should be allowed.
Most tracks are looking for more variety in engine makes, so you may be able to get them to bend the rules a bit for Pontiacs.

Too bad it's a claimer, #48 heads would work well.
Use ARP rod bolts instead of the factory ones and get the rods resized. Low tension rings should be OK since oil consumption is not a concern and they'll help reduce friction. You can mildly port the heads if the ported areas are shot blasted to match the original casting roughness.

Any rules against cutting the backsides of the valves or rounding off sharp edges?

Do the rules require a hydraulic cam?

What 2bbls are allowed? I think some of the Rochester 2bbls are good. I've heard some cheaters use the power brake vacuum port to suck in extra mixture from the gas tank fumes. Don't know if it's worthwhile though.

Try to find some rusted out/cracked Ram Air manifolds. They come up for sale now and then. Maybe R.A.R.E. has some rejects they would sell you cheap.

I don't think the '73-'74 EGR Intake manifolds are restrictive.

http://fiedlerh.home.att.net/

[Robert Williams]

Try Nunzi for the rocker studs, he has some without the hex but with a 1/2" inch bottom and 7/16" top for replacing pressed in studs, don't know if he has them in 7/16" X 7/16". He has a tech line between 5:00-6:00 pm EST. 1-718-331-3351.

Robert Williams

[Steve Barcak]

Yes, Fiedlerth is right! use ARP or aftermarket rod bolts and get them resized too. That's very important. OOOOOPS, I missed that one!
Steve www.pontiacheaven.org

[sdbob]

.If you can't use modified screw in studs usepress in oversize and freeze them warm the head and press in. then drill along side of stud, just nick the stud and press in a roll (spring) pin this works as I use to do this on all my early heads. Be careful as the bit can break off I know. I would suggest buying Herb Adams 'Chassis Engineering'book.The book deals more with asphalt but it will help you ($16.95).Your handling can make you competitive.Some parts you can make yourself to keep cost down.A friend use to run a GTO / 455 RAV semilate ,it was awesome ,Chevys did't like it.

[sdbob]

Since I am new I am still trying to use a computer.To continue my previous comments the chassis book tells you how to adjust your trailing arms for cars that turn left only. Other people probably know this but it sounds good.If you use a Pontiac windage tray drill a lot of 1/8 or 3/16 holes on the drivers side, this will break up the oil as it comes off the crank.Use agood oil pump melling, trw.Taylor had a nice article in Hiperf.Pontiac about oil pumps. Add some baffling to pan for sloshing and braking.Yes you want to make power but Keep it reliable!I read all I can about chassis design. Good luck.

[Tom Vaught]

Didn't they make a good head for the 74 350 CID GTO?

If you installed the Ram Air 4 cam Steve suggests
with Mr. Gasket type or ARP (no hex nut) type
studs and a 72 Intake you should be in good shape.

Unless you won a lot of races I can't imagine ANY
CHEVY guy claiming your engine just to have it sitting in his garage vs a Chebby engine he could use parts from. I would bend the rules like Mr.
Yunick would and go for it with a 2.02 intake valve and leave the 1.66 valve alone. (2.02 valves
come in corporate 350 engines, they did not specify brand specific!)

As far as oiling goes. Same deal as the engine.
Most Chebby guys would not claim your engine to get a "GOOD" oil pan so I would run a stock appearing pan with good internal baffles and a
welded back of pan deflector.

The oil scraper I would leave off unless you took the time to make a custom one as the typical 455
clearanced scraper will be too far away from the 3.75 stroke counter weights. If you do make one
it will help peel the oil off the crank on the left turns and move it to the right rear of the pan.

Tom V.

[basketcase70gto]

A buddy of mine used to run the hobby stock class here with a 74 catalina with a 400. The car came with 3.08 gears and he destroyed 4 motors before I finally talked him into a set of 2.56's. If you run a th400 like he did you have to account for the lower first gear ratio. All the sbc guys run the th350 with 3.08s on our 3/8 oval but the poor 400 couldn't handle the revs. Are you restricted on carb size? A 500 holley 2bbl was required here. Like Tom said nobody will want to claim you. It starts a lot of fights and paybacks are a *****. This car actually ran good when sorted out but with only one other pontiac in the field odds of getting claimed were pretty slim. The tech guys don't seem to know much about them either so anything that appears stock will probably pass.

[stuman]

Ok gentlemen, very good information flowing here (to be honest I was expecting 1 or 2 responses max).

What has been going on lately with what has been dubbed the “PONTIAC PROJECT� has been mostly research.

The screw in studs will not be an issue for one of the two following reasons – 1. A proposal has been submitted to the tech inspector for the track we currently race at for approval (no word yet) – 2. If we are disqualified that won’t be a big deal as this year is a test and tune year so finishing well (top 4) is not a big deal at all.

The heads I measured the valves – 1.96 intake – 1.66 exhaust (I think that is what they measured). Are the valve lengths the same between Pontiac and Chevrolet? I didn’t have time to cc’ them yet but we have located a Pontiac 400 that was removed out of a police car with 6x heads that will require some thought as which parts to use (6x or 46) would the crankshafts interchange as we found two spun rod bearings. Cutting heads around here prices run – 20.00 to 30.00 a surface, so we will be cutting both surfaces .060 (intake side and deck side).

We have found lots of good 2bbl Rochester’s and found great success in how they are built. IMCA has learned the trick of using the brake booster and pcv valve to supply additional air to the engine so they have modified the rules to eliminate them entirely from the engine (nice try – fiedlerh)

Rpm range has been discussed with a few engine builders and one race car driver and numbers vary – 5500 to 6250. ???????

Sdbob – I have owned that book (‘Chassis Engineering’) for years now, very technical information (as a mechanical designer I enjoyed it). Steve smith is also a good book author on dirt track racing though not so technical. In case you’re wondering the driver is a mechanical engineer. We have always added an ‘el chepo crank scraper, well, maybe that isn’t the correct terminology. More along the lines of a piece of steel welded in the right hand side of the pan to keep oil from sloshing up the side.

And lastly a RA4 cam recommendation. Cool.

[PONTIAC DUDE]

First off.If you want to win, then you need to take Full advanyage of the rules. Period.

Why give the competiton anything?

I have been building circle track engines for over 20 years and have many track records and championships to boot with my engines in all classes Mostly Chevies, but don't hold that against me. Ya still have to know what it take to compete.

Watch out on overbore as the Pontiac 350 is already a 354. But take full advantage of the cu.in.
If they allow adjustable valve train run it.
Cam? ty and find a 106 LSA and dial it in around 102 or 100.
Ya got to get off the corner, the chassis hook up & pedal response is your deal.
Intake? Carb?
If they allow pre 70 heads run them. 2.11/1.77 with 72 cc chambers are hard to beat. Compression is worth about 20hp per point.
Lighten that 180 gram pin, they will never know.
Cut the counterweights to balance, they will never know.
Hard to find a Cast 4 eyebrow piston anymore (Most were lighter then Forged), but maybe some N.O.S. are around, if not are Forged legal?
Main studs legal?

Maybe post the rules and then it would be easier to build you a Winning Combination.

But you still have to be......... a driver and have a car that handles.

And your night to win.

I loved that longer adrenialin rush, but very expensive without sponsors.

Owner of......The Quickest Pontiac Powered "REAL" Street car on the PLANET!!!!Will Race for Food.
Build it fast, build it right, build a Pontiac.

http://PontiacDude.cc

[J.C.you]

Have friend locally here that has been track champion with a poncho in a class similar to urs acouple of yrs ago. He kept the chevy boys "whinin" about that ole pontiac. He has dirt tracked poncho for years. He keep me out of 350s. U talkin about run one cheap, he did it. Got to where he could not find anymore 350s around and he went to a chevie 350, then sold his car.
I havn't talked to him in awhile and don't know if he rigged up another car or not. Main thing is to make it "turn the corner" and come off the corner pullin hard without spinnin. He had these two things "down." Oh yeah, he could play bumper pool with the best of them.
I would concentrate on making the car handle first and getting the most out of the motor second. Hey, I would't do anything to the heads as far as changing out rocker studs unless they make u. Just tell them they are stock. U are on the rite track to shave them as much as possible.Run plenty of octane if u use the cast pistons. If u run the cast rods be shure and check the big ends for roundness and put good rod bolts in. U might want to consider running mobil 1 and not skimp on the oil. Run a quart over full.U will have a quart in the top of motor and sloshing around and not in the pan.Make sure u have a GOOD COOLING SETUP. rad, water pump, buddy used to run water thru heater core for more cooling. Do u run power steering? another thing to have working rite. good luck

on a diet to go faster........

[Tom Vaught]

Agree totally with Ken that a rule book read by a few experienced circle burner types might yield
a wealth of additional ideas.

I have never CHEATED (as I was a Tech Inspector for racing for 11 years in SCCA Trans AM) but I
have have bent the rules to my team's advantage
many times.

A little known trick in Trans Am (with PG checking of cubic inches) was firing a Laser or EDMing a hole through an intake valve stem. This would bleed off compression to the checked cylinder when the engine was cranked over and show a legal cylinder displacement.

A team with the owners initials JR was successful in this arena until some mechanics bragged about how stupid the tech guys were. One of the guys
was cheating on his wife, she caught him, and as
payback she called us.

Guess who got caught during the PG check the next race.

Tom V.

[PONTIAC DUDE]

Here, the tech dude would come to the pits giving you time to...........

Hey Tom, Cigerette filters work great too.
Also try and cool the engine and claim a hotter engine temp, if he's not looking.

One idiot stuck a wire in the hole to hold the valve open a little and it broke off. They Had to pull the head the next day. Bwahahahaha.

If he let's you install the P & G fitting, leave it loose.

I would build a 350 +.030 with .030 pistons and a .035 bore. LOL
Offset the Chevy crank: 3.48 would be a 3.50. and agrue with them if they pull the head and check. Hard to find on a short track deal.

Hey, 3 cu.in. when you have to weigh 8.5 lb per cu.in. adds up.

But I never cheat. Smokey was my hero.

Owner of......The Quickest Pontiac Powered "REAL" Street car on the PLANET!!!!Will Race for Food.
Build it fast, build it right, build a Pontiac.

http://PontiacDude.cc

[ventura7211]

I thought the idea of roundy-round was using stock parts. That said the 46 heads you have should be allowed as all the heads had screw in studs from 73or74 on.

I do not have any first hand experience in circle track but I can tell that you should not be afraid to bend rules and cheat because almost everyone else will be doing the same. I know a guy how used aluminum heads and intake in a factory stock class, none of the tech officials clued in as the magnet would always stick to the motor. I have also heard of various methods to keep racers from claiming you motor ranging from oil placement on and in the motor during the race and other means of a more physical nature.

[J.C.you]

use the soft ear plugs doing the displacement check, alot easier than a cigerrette butt on the valves. another buddy trick

on a diet to go faster........

[sdbob]

You guys seem to have a lot of experience. I always liked when Pontiacs would whup up the other almight makes. JUst to tell a story a friend from Pittsbugh use to run a full size 61 faily successfully in semilate(2bl). He new the others were using max cubes, so he did also. Then he got into a 69 GTO(tempest body)with apartner. I had some friends in Ohio who had contacts with PMD. The car ended up with a RAV, 3" main Moldex crank cubes at least 455! The competition though since the crank was 3" mains the most ci. was 400 +.060 no bull. That car would destroy the almighty Chevys and Fords.That car would come off the corner and put at least 3cars on the next car they couldn't catch him till the next corner.The car was featured HO Racing News years ago. All good things come to an end though but it was fun while it lasted