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Im considering setting up a car for Lemons and Chanps racing. These are endurance races. 24 hours at average speed of 70 mph. I have 2 engines to pick from. One is an 87 307 from a Cadillac. The other is a 67 330 high comression. Can any one tell me what rpm range to keep these engines in for longivity? I have several trans with and without od , I have several differentials to chose from. going to adjust rpm range with rear and trans choice. Not going to buy any other engines trans or rears This is an endurance race on a budget that is rapidly evaporating.
1967 320hp 330= 5200 and 3600
1987 140hp 307= 3200 and 2000
If both engines are in the same running condition the 330. Its working very easily at 70 mph in 4th (OD). Assuming a 2.73 rear and over drive with a 26 inch tire = 1730 rpm @ 70 mph. If you go with a 3 speed auto no overdrive all else the same 2600 rpm @ 70 mph.
Fuel economy obviously depends on many unknown factors. Weight of vehicle, transmission, rear gear, tires, etc.
Just looking at the engine donors both being automatic while they accelerate as high as 87 mph.
A 1987 307 Cadillac is averaging 12.6 mpg stop and go to wide open highway.
A 1967 330 Supreme is averaging 11.6 mpg stop and go to wide open highway.
The Cadillac weighs 600 lbs more than the Supreme, that makes a major difference in mpg. Overdrive makes a major difference in mpg. Specs above are from Automobile Catalog.
If the Cadi weighs as much as the Supreme it gets 14.1 mpg combined average.
If the Supreme gets a THM200-4R it gets 15.0 mpg combined average.
Don't know what your potential peak mph is on straightaways or your lows on the worst turns. What track ? Determining approximate highs and lows will help fill in a lot of blanks...
Fuelly.com has tests on both models although the transmission for the 67 is unknown, or i just haven't located it. And the Brougham does not specify which 5.0 the 305 or the 307, or i just haven't located that as well. In any case the 307 averaged slightly better mileage than the 305. Specs below are real world.
1967 Supreme combined averaged 13.43 mpg after 84 fuel-ups and 14,864 miles of driving based on 1 vehicle.
1987 Brougham combined averaged 13.44 mpg after 83 fuel-ups and 18,821 miles of driving based on 3 vehicles.
And again the Brougham weighs 600 lbs more than the Supreme. At the Supremes weight it would be 15.0 mpg combined.
And if the Supreme gets a THM200-4R it gets 17.4 mpg combined average. These numbers are assuming a 2% change per 100 lbs of weight. And a 30% improvement for overdrive.
First order of business would be to make sure the valve train is up to it.
And you’ll want to configure it for rpms just past peak hp when going thru the gears. In addition, consider the load on the engine when it’s below peak tq. That’s a bit harder on parts.
Last edited by cutlassefi; Jan 26, 2025 at 06:19 AM.
Thanks guys This gives a lot to work with. The victim is a 64 Cutlass 2 door sedan. Not at all concerned bout fuel mileage. I have 2.61 ,3.55 and 3.73 rears. And more that I havent checked most likely in the 2.s. Transmissions switch pitch 400, manual shift, with a jetway convertor. 350 turbo, stout 2004r and a 350 turbo. I have a modified 4 speed saginaw with over drive from a 3 speed saginaw, Saginaw has the gearset with the low first gear. I will get all the trans ratios together Also have a 66 buick3 speed saginaw I have modified the core support to take the bigger 65 rad. I have confirmed Flowmaster G body small block headers fit. Writing this down .and reading it makes me lean toward the 330 with the 3.55 and 4 speed od . will put the ratios tgether
Ill go against the grain The 307 in our 84 Riviera has been pretty much bullet proof. The plastic timing gear gave up at 250K miles and I decided to got through the entire engine. I pretty much wasted my time as everything looked pretty much like new. When the car was new we drove it back and forth from Maryland to Boston several times and that is basically 70 mph for 10 hours at a time. It does not have a tach but it is probably running around 2000 rpm at 70 ?
The 87 engine should be a roller cam so one less thing to go wrong. The only thing I would do is change the timing chain set to a metal one and depending on the mileage maybe put a set of rocker arms and bridges on it even though the ones in my engine were fine.
Unless the 330 is a fairly new rebuild it is 20 years older. Also the 330 will need high test fuel where the 307 will run on 87
Sounds like he is trying to prep a 24 hours of lemons car. Those rules dictate no more than $500 spent to purchase and prep the car (not counting safety equipment). So items like full roller drivetrains are probably out of the question.
I i want to do the 24 hours of lemons . However cost of roll cage is prob gonna kill the project. Was quoted $3500 ouch. Gonna keep at it get it back on the road . With stuff i have laying around. Missed a gear last year, threw a rod in it. Its been a fun beater for long time. Been spending too much money on my 64 convertible thats frame off. Thanks for all the insight.
sell the switch pitch 400 to a 67 442 guy to recoup some money unless it's a big car unit.
Recommend you look at courses. Lemons is done at a track, there's no overdrive or highway there, it's all first and second gear stuff. Gambler is a road race.
sell the switch pitch 400 to a 67 442 guy to recoup some money unless it's a big car unit.
Recommend you look at courses. Lemons is done at a track, there's no overdrive or highway there, it's all first and second gear stuff. Gambler is a road race.
The enternet says average speed is 70 mph at a Lemons race . We know thats true. LOL. There is 2 races comming up, Im attending.
Thats a new one. besides those never existing…he said it’s a 67 HC 330.
So , 4 heads maybe?
It has #4 heads. If can get time im going set it in my bare frame and run it. its been in storage for a while. Cant get the car in the shop yet Have two cars parts cars Im dismanting, my convertible,sons Malibu coupe and the frame we just verified was in spec . Place is a total mess.
Thanks guys This gives a lot to work with. The victim is a 64 Cutlass 2 door sedan. Not at all concerned bout fuel mileage. I have 2.61 ,3.55 and 3.73 rears. And more that I havent checked most likely in the 2.s. Transmissions switch pitch 400, manual shift, with a jetway convertor. 350 turbo, stout 2004r and a 350 turbo. I have a modified 4 speed saginaw with over drive from a 3 speed saginaw, Saginaw has the gearset with the low first gear. I will get all the trans ratios together Also have a 66 buick3 speed saginaw I have modified the core support to take the bigger 65 rad. I have confirmed Flowmaster G body small block headers fit. Writing this down .and reading it makes me lean toward the 330 with the 3.55 and 4 speed od . will put the ratios tgether
Sorry. I am not sure. I bought them several years ago used. I will ck them for numbers. Looking at Flowmaster prices though, i would say they are Flowtech. Wont get to the shop till this weekend.
Welding a cage is something that most of the teams do theirselves, or ask someone who can weld. Their design is overkill just to be sure anyone can build it and still be safe with not the greatest welding.
70 MPH average??? For a 24h of Lemons, speed and more power is the last of your worries. Just making it to the finishline is an achivement on its own.
I would make sure you have a bigger sump so that you have extra oil in the engine. It is 24H Lemons so be creative and weld it up yourself.
Clean the returns in the heads from sludge (argue that the replacement valve cover gaskets are a safety item, oil on exhaust is a fire hazard :-)) and replace that timing chain (we all know the stock ones are crap and it is not visible from the outside).
As it is an endurenace race, lower power can be your friend, watching these 24H of Lemons races this has been proven over and over again.
I would go with an automatic and don't go crazy, just run your laps and drive like a grandma (instant team theme here, "Knitting Club Racing", dress up as old grandmas with big sun glasses, scarfs, handbags and knitting gear, ticking all the clische boxes).
An automatic is also easier for the other drivers in your car, or do you want to run it all by yourself?
Dale finally got the header numbers . Cant find them anywhere on the net. They fit in the frame.. Dont know if a clutch , or column linkage will work. Not concerned bout them, using floor shift . If i go manual will use hydraulic, if i have to. When I find all my clutch linkage, Ill see if it fits. Pic of header numbers attached
[Holy cow, dude - me and my brothers have been throwing the idea of Lemons around since my grandma passed away in the 90’s. Her Verdoro green ‘68 LeMans being the car - our name would be Ninja Grandmas Racing. All black nomex, Grey wigs, flowery aprons, etc…we’re shooting for Bowling Green this year but probably won’t happen
QUOTE=Altered 1978 350 Olds;1613795]Welding a cage is something that most of the teams do theirselves, or ask someone who can weld. Their design is overkill just to be sure anyone can build it and still be safe with not the greatest welding.
70 MPH average??? For a 24h of Lemons, speed and more power is the last of your worries. Just making it to the finishline is an achivement on its own.
I would make sure you have a bigger sump so that you have extra oil in the engine. It is 24H Lemons so be creative and weld it up yourself.
Clean the returns in the heads from sludge (argue that the replacement valve cover gaskets are a safety item, oil on exhaust is a fire hazard :-)) and replace that timing chain (we all know the stock ones are crap and it is not visible from the outside).
As it is an endurenace race, lower power can be your friend, watching these 24H of Lemons races this has been proven over and over again.
I would go with an automatic and don't go crazy, just run your laps and drive like a grandma (instant team theme here, "Knitting Club Racing", dress up as old grandmas with big sun glasses, scarfs, handbags and knitting gear, ticking all the clische boxes).
An automatic is also easier for the other drivers in your car, or do you want to run it all by yourself?[/QUOTE]
i attended the race at Pittsburg International. No longer ininterested in competing. too hokey . Im just going to make the car safe and get it back on the road. Dailer driver beater.
The 307 in our 84 Riviera has been pretty much bullet proof. The plastic timing gear gave up at 250K miles and I decided to got through the entire engine. I pretty much wasted my time as everything looked pretty much like new. When the car was new we drove it back and forth from Maryland to Boston several times and that is basically 70 mph for 10 hours at a time. It does not have a tach but it is probably running around 2000 rpm at 70 ? 
