[dirt track pontiac]

Hey guys, im a new member here and i have a few questions to ask. I have a dirt track car and i need some adivse on it. I have a 81 Pontiac Gran Prix and im putting a Pontiac 350 in it. I need some help on installing the motor and building the engine. Also any dirt track setup information for the car would be helpful!! Thanks

[Sirrotica]

Welcome to PY.

What are the rules like? It makes a big difference what suggestions we have, without any idea of the class rules. What engine did the GP come with?

Nice to see someone running a dirt track Pontiac.

[dirt track pontiac]

The Engine: NO stroking or de-stroking. Maximum cranking compression 175 lbs. (ignition off, engine turned over 5 times)

Hydraulic cam and lifters only. .447 maxium lift. Must maintain 14" of vacuum at 1200 rpm. Open chambered heads only. NO porting, polishing, or gasket matching allowed.

Stock cast iron exhaust manifolds only.

Holley 4412 2-barrel only.

Can run racing gas!!

Thanks for replying, hope that helps!!!

[Sirrotica]

Be better to start off with a bigger engine than a 350 if possible, any reason for not going to a 400 or 455 the weight is nearly the same and the larger cubes along with more torque and that is the thing that gives a Pontiac an advantage off the corners? I will reserve head recommendations until the cubic inch size is determined. What is Max. tread width and do you have top run DOT tires or race tires?


For camshafts a 9779068 would work with 1.65 ratio rockers and be fine with the vacuum requirements. With 1.65 rockers it comes in right at .447 lift too. using 1.65 rockers also gives you a hair more duration. Camshafts with specs are are listed in the link below.


Ram Air III exhaust manifolds with 3 inch pipes with an X or an H pipe, and a Q Jet 4 BBL iron intake manifold with a adapter, this will give you a larger plenum volume than a 2 BBL intake.

http://ronspontiacpage.com/reference-pages/crane.htm


Is there any possibility that you can direct me to the web site so I can check all the rules?

[dirt track pontiac]

Sorry to just be getting back to you, we have been racing the dirt track car (Pontiac Bonneville with a 400) this weekend!

Heres a link to one of the tracks we run at. They have their rules posted on there.

http://www.arklatexspeedway.com/

Thanks

[PontGuy]

I ran Pontiacs on dirt tracks back in the 80's and did quite well. Stuck with Lemans and GTO bodies (same thing once you strip them down) and a Pontiac 350 for power. Similar rules except for the 2 bbl Holley- that's a wierd one. I found the 350s are a lot less prone to overheating and don't run as soft when they do compared to the 400's, which was very important when running on the dirt.

Run the biggest valves, cam and CR that you think you can get away with. Bottom end torque is meaningless on the dirt track. Mid range power gets you out of the corners and you need to turn up the RPM down the straights. The Pontiac mid-range torque is a plus compared to the Chevy and Ford engines as long as you can keep it pulling down the straights. Finding the right gear is also important to this. And weld it up so the axle is locked.

Setting up the car/suspension is just as important as the engine and the list of tricks is way too long for this post. Learn about cross-weight and tire selection, get the right springs on each corner, play with the camber/castor, see if you can work out the bump-steer, pay attention to weight distribution when building the roll cage, etc. especially since the Pontiac block is on the heavy side. You will know when you are getting close when you find that you need to glue the tires to the rims to keep them from peeling off!

Also remember that stock car racing is "controlled cheating". You usually can get away with more than you think.

Walt

[dirt track pontiac]

Where do i get the motor mounts to a Pontiac motor in a g-body car?

Thanks for your help

[PontGuy]

The newest "old" Pontiac that I owned was a '79 GP and I yanked the 301 and put a 350 in it. If I remember correctly 350/400/455 should fall into the 301 body mounts just fine as long as the block is a 70 or newer and has the 5 mounting holes on the sides.

1980 was the last year for the 301 engines, but if the GP frame was unchanged in 1981 it probably still has the same mounting holes, so all you would need to do is get a pair of body mounts from a late 70's GP parts car that came with a 301, 350 or 400. Some of the 455 cars came with different mounts (at least on the A bodies.) And the good thing about a race car- if it doesn't quite fit, cut some new holes and make it fit!

If you post on the "wanted" section of this forum for this sort of stuff you are very likely to find people with parts cars eager to sell to you, usually a lot cheaper than e-bay or going to a parts yard, though a good local parts yard with some old GPs would probably be a good thing to find.

While you are at it you may need a trans, cross-member and driveshaft to match it all up. By the way I ran the same TH350 on the dirt track for years, and just couldn't break it no matter how hard I tried.

I see you are already thinking like a true dirt track racer- put a big CI engine in a car that wasn't really sold that way, but is essentially the same as earlier cars that did come that way...

[dirt track pontiac]

thanks i might not be able to get the gp. i might have to settle with a monte carlo,regal or a cuttlass, for as the trans. i was thinking about using a manual. for the clutch we have to run a 10.5", this is a very competative class on a reg. night there is about 30 cars and sometimes more.this past weekend there was about 70 or 80 cars here to try and win the 5000 to win and there was some fast cars. so i need to all the cheating tricks there is know. thanks

[Sirrotica]

Regals had 301s in them too.

My personal experience I always used a T 400 tranny, if you have to stop on the track or happen to spin out the car is already back in first gear and all you have to do is stab the gas. T 400 has no detent cable to worry about either, even if the motor stalls you only have to restart it as I always bypassed the neutral safety switch, you don't have to worry about finding first gear. A T400 with an 11" T 350 converter gives you a little more stall speed than the stock T400 12 inch does.

I really don't believe you have to circumvent the rules with a properly prepared Pontiac. You already have a big advantage as no one knows anything about them and the Ram Air manifolds give you a big advantage over chevys and fords as well as our excellent cast iron intake. I ran within the rules and beat many chevy guys that weren't within the rules.

Any big valve 400 head from 68-70 GTO or GP along with same years intake with the heat crossover blocked. These choices would keep the compression up on a 350 as well as breathe well. A good oil pump along with a pan designed for oval track or a stock pan modified with extra baffles to keep oil around the pickup. Run your rods around .0025 and your mains .003-.0035.

1 1/4" second gen Trans Am front sway bar and shorten the left sway bar pin 3/4" to preload it. Use the nylon bushings with it and I used a 7/8" rear sway bar. Stock coil on the left rear and left front I used a shortened station wagon spring on the RR and a station wagon W/AC HD coil cut down on the RF. I tried to keep my car close to level and ran 3 inch stagger in the rear.

I would recommend the adjustable stock location street stock shocks that many of the oval track suppliers have. Also either a T/A or Z28 steering box from 82-92 cars I would try to get the steering about 2 - 2 1/2 turns lock to lock.

I tried to have around a 6.00 to 6.20 final drive ratio for 1/3 mile medium banked track. 2 ways to get there is with a T400 in first gear with around a 2.50 rear axle, or second gear with around a 4.10 rear axle. I like a good posi unit over a locked rear but that's my personal preferance.

Hope this gets you started at least.

[PontGuy]

Sorry I wasn't really recommending cheating, and everything I did was defensible- but I had no problems pushing it just as far as I thought I could go. And I found that running a Pontiac had lots of advantages because a lot of the rules were set up around Chevys and Fords, and nobody knew much about Pontiacs. So I used that to my advantage.

My best setup was very similar. Started with a 350 block with nothing fancy- cast pistons etc. The only restriction on heads that applied to Pontiacs was no screw-in studs, so I found a pair of '67 190 heads, which came with pressed in studs but still came with the big valves and small chambers. We had some restrictions on cams (forgot what they were) but I tried quite a few- the 068 was a good start but I found some better. I did have to chamfer the bores for valve clearance at the maximum allowed lift. We also had to run a factory cast iron manifold and factory carb- no problem with the Pontiac intake and Q-jet with the right jets and good secondary rods. We had to run log exhaust manifolds so no advantage for me there. But I made a lot more torque coming out of the corners than most of the Chevy/Ford guys with this setup and could pull up to around 6,000 RPM.

I used a TH350 in second and I found the best gear for the track that I ran was a 3.55. I would not recommend running a stick in a "stock" class. The auto trans is way easier to manage. I actually preferred a column shifter (tried both column and floor) with the detent plate modified so that I could slam it back and forth between first and second. This was useful on restarts especially if I was out in front.

Suspension setup was critical. The track I ran had high banks so the right front spring had to be very heavy, and the rest matched out so the car would corner reasonably flat but still have some give. I forgot about pre-loading the front sway bar. In addition to staggering the tires at the back, the tire diameters in the front affect the weighting on each wheel and I used this to fine tune. I liked my car on the loose side- a lot easier to control than a car that pushes. Tire compounds/tread also made a big difference. I never quite got it figured out, but the right tires for a given track condition seemed to make a huge difference. Sometimes I could just run away from everyone and sometimes the car worked me to death.

I played the dirt track game for several years and did very well for a low-budget "team". 30-40 cars on a given night was not at all unusual for my class. Won a few and just about always placed in the money. And the whole time I was the only one that ever ran a Pontiac.

[dirt track pontiac]

hey guys yall or a lot of help. as far as the cheating goes i don't like that much but if that's what i have to do i will a little bit. transmission selection is crazy to because i do like the 400 & the 350 i thought the manual might be better be cause it was light. right now i'm running a super turbine 300 in first gear with 3.42 gears that gives me a 6.22 final gear.the rpm on the track is about 5800 or 5900 rpms. for the rules here it is the same way everybody knows everthing about a chevy & a little about a ford & that's it nobody here run's a pontiac which is good for me . your set ups are good information and it's nice to know how it was before all of the new springs & shocks combinations there or know. the sway bar is some good info. but now u have to constantly put these cars on the scales to make sure your setup is were it needs to be. sorry about my typing i'm new at this but i like talking to you guys. i might have to ask yall some drag racing questions one day my best freind drag races and he's the one that got me into the pontiac .he races 68 firebirds that will fly and he's also crazy enough that he rides with me in the dirt track car isn't that wild a passenger in a dirt track car one more the before i go is i wish that i could find somebody that make a power steering bracket for a aftermarket circle track power steering pump thanks once again for everbodys help mike

[Wild Bill]

The big drawback to running the Pontiac in a circletrack is the extra weight up front compared to an SBC. Shoot for more than 50% rear weight. Set back the engine if the rules allow. 1/2 an inch will make a difference even if the rules say no setback and will be undetectable by any but the most astute tech person. I vote you keep the ST300. it weighs less and has less internal inertia to accelerate coming out of the corner. I have never actually seen one but I think it is essentially a Powerglide with a BOP bellhousing. (don't shoot me if I'm wrong!!) A stock powerglide is almost indestructable in even a heavy 3500# Hobby Stock type car. Chevy made an air cooled version of the powerglide used on 6 cylinder cars. It has an 11" converter which is -you guessed it- lighter. If I am correct that the ST300 is essentially a PG then it should fit. It had ribs on the back side of the converter and big ventalation holes cut in the bell housing. You can probably leave off the tranny cooler even if you don't find an air cooled version or you can move the cooler to the back of the car somewhere that it will still get air flow across it if you feel uncomfortable about leaving it off. Stay away from the Th400. Too heavy both overall and too much mass to accelerate. The constant acell/decel is hard on the Th400. The TH350 is cheap and reliable. The TH200/250 is another inexpensive lightweight option but not as durable as the PG. If budget and rules permit buy a 10" converter specifically designed for circle track. TCI made the one we used. Or if rules permit, several companies make converterless PG's tho I never used one as my rules required a working converter. You can get a dummy converter to make the converterless PG look right but it won't fool any but the most ignorant tech. It sounds just like a clutch/manual setup when you first move the car from a stand still. We had some leading competators use them and appearenty they were quietly told to get rid of them as they were changed out after a couple of weeks of complaints but no DQ's.

Prefered is a clutch w/ 3 speed or 4 speed tho. Lighten the flywheel or buy a good lightweight aftermarket one. Use the smallest lightest clutch you can find. Once engaged it won't slip. If you're geared right shifting won't give you any advantage. Even on a restart any gain from shifting would be offset by loss of concentration when your attention should be on setting up for turn 1 and positioning the car to pass the guy ahead of you at his 1st mistake. The faster you can spin up the RPM the better. You don't want to waste any more HP accelerating that rotating weight than you have to. You are doing it twice a lap and even a small amout of reduced weight helps. Save that HP for accelerating the car not the drivetrain.

If rules and budget allow put in a Ford 9". Three advantages from this. It is much stronger than the 7.5 rear you have. You can get any gear from low 2.41 to 7.5 something in small increments allowig you to run in high gear (less drag) at the ideal RPM for your motor. Third it gets into that gray area some call cheating by letting you place the control arm pivots at locations that optimise traction to deliver all that Pontiac torque to the clay instead of spinning in much the same way the drag guy's try to maximise traction at launch. The factory 4 link leaves a lot to be desired when it comes to circle track racing but with a little tweaking works well. Welding the spyders is OK but clean it out real good when you are done. The slag beads are murder on the bearings. Better still is a spool if the rules allow. Lighter too for less inertia.

Try this link for a lot of very useful info and advise. It is very similar to this forum in the openness of advise given, just a different topic.

http://www.thedirtforum.com/

Lighten anything in the engine you can. 326/350/389/400 cranks are esentially interchangable. research to see if the 326 is lighter and use it if it is. We ran the SBC and turned 6-7000 RPM with cast cranks and stock rods. Cast pistons didn't hold up and hypers were a mixed bag. Forged pistons may be hard to get for the 350 Pont. Custom lightweight forged pistons with lightweight pins would be pricey but worth it in my opinion. Dropping piston/pin weight on a 350 chev from a light 550 grams to ultralight weight sub 400 grams made an explosive difference even in a "stock" class where we were producing around 350 HP with similar cam rule to you (465 lift and 14" vac) If stock rods are required thats 1 heavy item you may have to live with. A circle track type pan is also manditory whether purchased or a modified stock pan unless your rules forbid it. Research the Brezinske site for any exhaust ideas you can use. Don't scimp on the valve springs. You don't want valve float to be your rev limiter. Depending on how and where they measure the valve lift you may be able to get away with much more valve lift than the rules state. If they measure at the valve they may not have the dial indicator parralell with the valve resulting in less indicated lift than actual. If they measure at the lifter, well.....

For those not aware the 4412 is the universal circle track carb at most tracks. It is used as a restricter and equalizer on classes from pure stock (Strip the interior, put in a cage and go racing) to IMCA Modified's and Limited Late Models (All out race cars with esentially only carb, weight and tire limitations to make them competative and "affordable"). Don't poo-poo this "500cfm" carb as many of these circle track guys are getting HP numbers from 400-430 CI SBC's similar to your big inch Pontiacs. I wouldn't call them steetable tho with an idle of 1500-2000. As with many of you attest to Cliff's quadrajets being a step above so too some 4412's are "more equal" than other 4412's so for a price you can get a massaged carb that can make a significant difference.

Chassis setup is an art. So is driving. These 2 items are the most important and what actually determine who wins most races not how much horsepower is under the hood. They are also the hardest to sort out. If you took the engine in 1st place car and swapped it with the engine in the last place car the last place car would probably still be in last place and the 1st place car would be in the top 10 if not the top 5.

Good luck and have a blast. It's better than sex unless you're not getting any.

Bill

[PontGuy]

This thread is fun just because it brings back some good memories..

Yes the disadvantage of the Pontiac engine is the extra weight. The advantage is all of the "natural" torque it has. I would never try to run a Pontiac engine in a higher class car but it worked well for me in the street classes because it took less mods to make good power and hold it all together.

Some differences between SBC and Pontiac running street class on the dirt- figure 1000 RPMs lower on a Pontiac compared to a Chevy for similar horsepower, this reduces optimum gear ratio and reduces the need for a loose converter. It also makes valvesprings, etc. less of a concern. I ran cast pistons without any problem. The Pontiac weakness is the rod bearings but not sure how to solve that without spending money. You don't really need a special oil pan on a Pontiac engine. The pump WILL run dry on extended right hand turns using a stock pan, but I found it gets plenty of oil going left.

I agree that in the end the engine is probably less important than suspension setup.

Also I always felt that racing was 30% skill, 30% the car, and 30% luck. Good drivers will do OK in a poor car, poor drivers will always drag behind no matter how good the car is, and everyone has races where unfortunate things just happen.

Walt

[Sirrotica]

Proper clearances, a good oil pump and driveshaft, and a modified pan will keep the rod bearings intact. The little bit of extra front end weight over a chevy isn't going to be a huge disadvantage to overcome. Here are 2 good threads about oil pans and windage trays for Pontiacs:

1.http://forums.maxperformanceinc.com/...hlight=oil+pan

2.http://forums.maxperformanceinc.com/...d.php?t=609229

I don't see why anyone would be afraid to use a Pontiac in higher HP classes, I did it and would run with or outrun any other brand, Ford Chrysler or chevy. It just takes a little ingenuity and sense to run with other brands same as it does in drag racing. The Pontiacs ran with all the other brands in their heyday in Nascar and can still do it with determination and work.

Jim Butler built a Pontiac engine for a dirt late model down in Tenn. and it's competitive, just not as cheap as a chevy.

If a dirt car doesn't handle and hook it makes little difference what's under the hood, If the driver can't drive you might as well leave the car at home in the driveway, you'll have about the same chance at winning a race.

[PontGuy]

I have absolutely no doubt that running a Pont engine in higher classes can be done very successfully. But building a Pontiac engine has always been more expensive than SBC, and now that they haven't produced one for 20 years I think the gap is even wider. Also as you mention the knowledge base essentially doesn't exist so it would take personal experience and ingenuity to set one up. So it would take the desire, and the bucks, and the knowledge. Based on your sig it sounds like you have all three, but most of us don't- and the engine is just one small part of going racing.

I ran the same Pont 350 block for several years and never spun a bearing. But the guy I sold it to did spin one the following season.

I just checked the pan links and they are discussing how to keep the pan from running dry on right hand turns. I've experienced the same with my street Pontiacs and know to be careful on freeway entrance loops, etc. But I never saw my pressure gage blip on the racetrack. Now if we were running clockwise instead of ccw...

[Sirrotica]

As the tires get wider in the upper classes is when it becomes an issue and the oil pressure fluctuates more on left handers. When I autocrossed my 73 T/A and with street tires it wasn't a problem, however when I put the GoodYear Bluestreaks on is when I had a rod bearing spin.

However I built an engine for a street stock for a friend of mine and although it never hammered a bearing, when I pulled it down after 2 years there was plenty of evidence of bearing damage. I suspect even though the gauge doesn't drop enough to see it is being uncovered and sucking air briefly. Sometimes running 7 qts. of oil will band aid the problem, but I'd rather do some mods to the oil pan to be sure.

Accusump is another way to help the problem but again a band aid and not solving the original problem. I don't know if it would be protested at the OP track or not.

Pontiacs design flaw is the wider pan, and thus the tendency for the oil to run away from the pump under hard cornering. Most other brands have a much narrower sump and that alone helps keep the oil around the pickup. If a little attention is paid to the pan before hand it will probably save money and labor down the line.

I doubt I have much more resources than anyone else on here but I do have possibly a little more experience with this type of racing as dirt racing is pretty much unheard of with Pontiacs even on this board. That's the price we pay for using an engine that has no where near the development effort and money directed at it as compared with chevy Ford or Chrysler engines and I'm glad to have someone on here profit by the errors I made when I ran Pontiac engines in this type of racing.

My dream if I was ever wealthy would be to field a Pontiac powered 410 sprint car as there are aluminum blocks now available and it is feasible. I remember when I was about 10 YO my Dad taking me to a super modified race (That's what sprints were called back in the 60s) and going into the pits after the races, most cars were powered buy sbcs but there was one powered by a 389 Pontiac and I will always remember that car.

My own project is to build a street driven Nascar clone car with a 86 GP shell on a racecar chassis. The car will have a 455 Pontiac and be as close to a cup car of that era as possible. I just acquired the chassis and hope to make some major strides on it this year in completing it. I will have it paint scheme to closely resemble the 69 428 HO GP I used to race back in the 70s on the local dirt track near Erie Pa.

[PontGuy]

I can believe that, I found all sorts of things can become a problem as you pull more and more G's.

I was fresh out of college with a day job, and married with young children when I started racing dirt track (Sumter SC). So I couldn't afford to make it any more of a priority than I did. The challenge was running a low-$$ operation and still be competitive. I did good enough to earn some sponsorship, and discounts at the local parts houses and junkyards. And with the payouts I won I actually spent very little money racing. The time that it took was another thing entirely, and that was the reason I had to quit.

Sprints have never been big in the SE, but I have a buddy that lived in Reading and drove outlaws a while back. Every now and then we go out to one of the local tracks here and watch the guys run for old times sake.

Running a Pontiac engine on the dirt was an odd thing to do 25 years ago, can't imagine there are many trying it now in any class. Would love a good opportunity to share knowledge but it seems that we have lost the guy that started this thread..