cutlassrichard

Hey Guys, I have a serious question what cam should i go with for my 350 olds that im rebuilding this weekend a comp cam 268 h or 270 h and can i use it with my stock valvetrain.......right now im doing everything on a budget because im a struggling college student at University of Northwestern Ohio. The Irony is I Major In High Performance but i have not made it to the engine class yet i want to build my engine to be a daily driver with power. im also putting on #5 heads from a 1968 cutlass with a performer 7111 intake and a set of headman headers in my 1978 cutlass supereme brougham. I Need Help Deciding because i want to retain my stock valvetrain untill i can afford roller rockers

krooser

I think you'll need more compression if you want to take advantage of the 268H.

While Comp is the "800lb Gorilla" when it comes to cam companies, there are many outfits who can provide a cam for your Olds... and may even have a better grind for your application. Member Cutlassefi is a dealer for Lunati and Erson. I got my race cam from Charles at www.camcraftcams.com .

Bigger isn't always better.

DoubleV

What will your CR be with that head swap? Need to know gears and stall too.

cutlassrichard

i will be at 9:5.1 im using .28 head gaskets, right now i have the factory gears in the rear i belive 2.19 or 2.56 but they are getting swapped out for 3.42's and i would like to run a stall of 2200 or 2500 on my th-350

cutlassefi

You have a perfect candidate for an Erson TQ40, it's 220/228@.050 on a 110lsa with .504 lift on both. It'll work fine with decent springs and an otherwise stock valvetrain.

Thanks.

cutlassrichard

thank you cutlassefi, where do i order the cam because i went to the erson site two days ago and i couldn't find anything for oldsmobile ,and with that cam i could still use the stock pushrods and rocker arm setup, i can spare the expense on springs

362

Stock valve trains like equal lift lobes. This translates into equal base circles. The lifter preload is easier to obtain with only shimming. That is why the factory cams were that way. But there is room to play. I am running an Ultradyne 207/217 262/272 with a .461/.484 lift. My preload worked out between .030 and .050" It runs just fine with stock rockers.
Just a note. My compression is 9.5:1 and this cam makes 17" of vacuum at 750 rpm, so my brakes work great. It doesn't take too much more before brakes can get questionable. Example. Another motor of mine is at 10.25:1 with only 4 degrees more timing everywhere and a 2 degree later closing intake, and only makes 14" with a hint of a lope. If it's street driven, I would pay attention to low and mid range power, and stay away from fast ramp cams. The old 204 214's are just fine for low compression and probably more than they get used for.

501Paratrooper

Get your cam from cutlassefi, great guy to deal with!

cutlassefi

Thru me. Send me a pm with your email etc. Thanks!!

joesw31

That sounds like a nice cam for a 350!

362

I have played all over the place. This is just an excellant street cam.

DoubleV

Just make sure you will actually have 9.5 CR. Don't assume anything and make sure you measure everything correctly.

362

Dear DoubleV. I am new to the sight, not to engines.

DoubleV

Dear 362. I was talking to cutlassrichard not you and was just trying to make sure he doesn't make the same mistake MANY others have done in the past.

362

Sorry about that. I have not quite figured the flow of things yet

J-(Chicago)

tq40 should be a good cam. I just don't see you needing that much lift. just be sure the valvetrain is spot on. Personally, i stay under .5 for stock valvetrain and would rather modify the bowls. Especially if you're running those aluminum rocker junks. You cant even shim those correctly without mushing them, and they are fragile.

cutlassrichard

I May Have To Wait A Few Weeks Before I Order Or Ebay Off My Holley 650 I Was Going To Rebuild At School And The Edelbrock 3711 intake thats on the motor now along with my fresh rebuilt #8 heads so i can rebudget im over 400 dollars ......it really sucks at this moment because i wanted to replace the edelbrock cam i have in the motor now because its not doing my car justice and also the fact that i have to replace my crank as well.

cutlassrichard

I Also forgot to mention the engine is a 73 350 with the crappy #8 heads, i planned on reusing the stock pistons since they are still in good shape and also since its gonna be a daily driver, i hope i can get decent compression with the head change and the thin gasket good thing is i can have the heads milled for free at school.

J-(Chicago)

if you bolt on #5's with a .028 gasket you'll only be 9.2:1 at the very best. I think you need to partially rethink your plan of action. That free milling will be a necessity.

J-(Chicago)

The stock qjet was 750 cfm. I'd run a 770 avenger if I were you once you reach your cam and compression goal.

cutlassrichard

yeah it will, because i can only take em to the machine shop at school this week and if i dont i have to wait another seven weeks.

cutlassrichard

i will defitnely talk to cutlassefi soon about a cam once my budget opens back up, i need to sell my some of my old parts thats coming off the motor to re-coup most of the money i spent the last two days to prepare to replace the crank and bearings and other go-fast goodies i purchased. as long as the engine does decent i can see my self having cam rockers sooner btw i have a picture of my car on my profile with me standing next to it

J-(Chicago)

in my honest opinion, i'd mill as much as possible. you can always relieve the chambers bigger by around 5 cc by polishing them later on down the road if you're a tad too high..

362

Cutlassrichard. I noticed in your post you are a North Western student. Well, we live in central Ohio. Get hold of me and we'll go for a ride in my 68 powered, 85, 442. See if you like the power level and I will share with you exactly what's been done. It always put's a smile on my face.
If you added up all the horse power numbers from all the components out there, we would all have 1000 HP rides. Go slow !!!

cutlassrichard

362 im also a lima native as well, i figured i go to school in my hometown and i love cars especially fast oldsmobiles. and i will pm you, i love the 80's 442 i always wanted to own a 1986 442 thats black and silver got to have the car that matches my age

362

Mine is black and silver with only 62,000 original miles. So I never went crazy cutting it up with modifications. It has won the Dick Miller Oldsmobile G-body event both times I have entered it at Norwalk. Will be trying for #3 this summer.
I would like to post a photo but the camera is down and this is a new computer. Lost a ton of stuff to a mechanical hard drive failure.

cutlassrichard

that is my favorite color combo and i don't blame you my cutlass was all original until the 260 decided to die on me 7 years ago. it had 106,952 miles original . and dick miller has events in ohio i always wanted to meet him or bill trovato but i wont until the engine masters challenge later this year.

362

Mine is not stock. Those 307's just didn't have it.

cutlassrichard

whats all been done to your 350

362

1968 350. Stock #5 heads with stainless, under cut valves. Stock sizes. Comp Cams springs #942-16. Stock manifolds. True duals to the rear with stock 442 tail pipes. "You can still get them"
I had it bored .067" over to use some 425 pistons I already owned. Compression came out at 9.62:1 with a .045" gasket. Stock style, 455 timing set, Cloyes #C-3082. Cranking psi is 170 psi., and a high torque mini starter.
Ultradyne hydraulic flat tappet cam, grind OL262/272H112, Crane stamped rockers, HEI distributor, Stock Melling oil pump and a true 5 quart pan and a 425 oil filter. The 307 radiator was not cutting it on warm days, so I am using a Bcool for a G-body. The a/c works. Also installed an Eaton posi with the stock 373's.
I took it to an 1/8 mile track to see what I did. The best was a 1.9 60ft, and 84 mph 1/8. I have lost the timing ticket and cannot remember the time.
Is it a race car? NO. But very fun to drive on the street.

coppercutlass

I ran the 260h which i belive is one cam under the 268h and i ran that in a 9 to 1 combo based on a 73 short block that was just re ringed nothing fancy, with freshend up 7A heads 72's stock valve train , with an edelbrock preformer intake 1405 eddy carb full length headers, x pipe, 3.73 gears i ran 13.86 .

362

Coppercutlass. That is respectable. My exhaust manifolds are holding me up to some degree and am considering Sanderson block huggers. May even go with a larger cam and high bleed lifters. "A poor man's roller". But this thing has outrageous torque, and those things are not realized until high rpm and racing. One big smokey burn out with 18 psi air in the rear tires is how I managed the 1.9 60 ft. You can't do that at a red light unless you want blue lights behind you.
I am just lining out some things to help the original poster of this thread

coppercutlass

I just posted up my experience with a smaller cam than what he wanted to use. more or less giving him ideas.

362

That Edelbrock he has should be doing it. They did their dyno stuff on an
8 to 1 350 with the Performer package, and 9.5:1 with the Performer RPM. I once talked to their tech in depth. If you look at their Performer power graph, that cam is holding torque within 30 lbs over a 3000 rpm spread.
That cam has considerable off seat timing and is on a 114 LSA. I have often thought it would be better suited for a higher compression ratio. They state 16" of vacuum at 1000 rpm. So what would it really be at say 700 idle.

cutlassefi

362, so we all understand, I'm wondering if you could clarify a couple of things for us please.

1) Seeing as how all 64-90 Olds timing sets are the same dimensions, what's the difference in a "455 timing set"?

2) Seeing as how it has nothing to do with the difference between a flat tappet and a roller, how is a larger cam with high bleed lifters a "poor mans roller"?

And just an fyi, a cam with a wide lobe sep, i.e. 114, should have a wide, flat torque. That's typically the effect a wide lobe sep has.

Thanks in advance for your clarifications.

362

I thought there was no difference in chains either until I held both in my hand. The part I listed is heavier.
Roller: A roller will let you install a larger cam than one might use because of speed in closing and opening valves. A flat tappet that is too big for say street application with power brakes, can be toned down a bunch with Crane, or Rhoads lifters. Restoring low end torque and vacuum. But pump up at 2500 to 3000 restoring full lift and duration. Variable valve timing! So you can have both. Some call it a poor man's roller.
LSA. If you look at what manufactures are putting in their 11,12, and 13 second cars. They are wide LSA with short timing at .050. My friends 2011 Vette is only a 205/215, but on a 115 LSA and high compression. Those things run high 11's.
That is why I have wondered how that 114 LSA, 204/214 Edelbrock would do at higher compression. Although it's a small cam and make great cylinder pressure, I would think it would spread the power out over a wider range. No one I know has tried it. They just jump to a bigger grind. I may have to be the test.

cutlassefi

I thought maybe you didn't have a good handle on this. For all, here are the facts;


Do what you want, but there are no revelations there.

362

You know, I am 62 years old and have built more engines than you could possibly imagine. High bleed lifters were created for cheating with a larger cam in vacuum rule classes. As for the rest, you seem to know it all. I have tried being a member of various forums over the years, but there is always someone like you.
I won't insult your vast knowledge anymore.

cutlassefi

I have no problem with you. Simply explain the "455" chain set thing, same manufacturer to same manufacturer. I'd like to know what manufacturer differentiates and why, I'll call them.

Then explain the larger roller vs a smaller flat tappet statement. I'm all ears, really.

And in all those engines you've built you've never tried higher compression with a wide lobe sep, really?

And explain the cam configuration comparison between a late model LS vs a sbo and why if you would please.
I'm being very serious here, I'm all ears. Maybe we can all learn something.

Thank you in advance for your input.

61reoldsman

Boys lets not start slinging mud , we all can learn from anybody who builds engines for paying customers . Camshaft selection has to be one of the hardest things to figure out for each persons engine combination .Start researching on the web all the terms associated with a camshaft and pretty soon it either starts making sense or you become more confused . A conversation with a professional is the next step ,whoever it is.Choose wisely ! Good luck and may the force be with you !!