Camshaft question

MUSTANGPAT93 · 08-11-2009

I am building a scat 331 stroker for my 93 cobra. the original motor only had 114k miles on it and the only reason its getting a rebuild is it cracked 4 pistons, and i dint have a really good reason why. A few of my dads friends including him have been telling me for the last week to reuse the stock camshft for the motor build. I didnt mind the cam in the stock motor because i have enough bolt ons to make up for the power loss from the cam. I dont believe the stock cam is bad but there is far better now a days. I looked on the internet last night to see what people were doing for boosted stroker motors and it was half and half. Some people posted horsepower charts on what their 331 did with a stock cam vs aftermarket. Best i could find was a 5hp gain over stock and that was the tfs stage 1 cam. I am now starting to consider using the stock cam even though i dont feel its right. Money is pretty tight right now and i cant afford a custom grind cam and i have to keep in mind valve cover clearence because of the tfs heads. Anyone have any input on what im considering doing?
__________________________________________________ _

93 cobra
soon to be scat 331 stroker
trick flow aluminum heads
centerforce stage 2 clutch
jba headers
powerdyne supercharger
steeda adjustable clutch cable
bbk x-pipe
flomaster catback
short throw shifter
eibach lowering springs
subframe connectors
fluidyne radiator
cervini mach 1 hood
Work in progress!

**RLG34750** · 08-11-2009

For what you are building a custom grind cam would be the way to go......

surprisingly its not a lot more money than an off the shelf model.....

KLWorra · 08-11-2009

I am not sure where you found a cam only got 5HP.

With all the other money you got into this thing with those heads a cam would be a no brainer. Would just need to ensure the intake also get upgraded and matched to the cam and heads. I would think 50HP would be an easy gain.

I paid $195 for a custom grind cam with highly custom journal sizes--I run full roller roush cam bearings. Predator Cams out of PA. Call em and get a recommended cam, they are very helpful.

Keep in mind the 331 will be a bigger pump and will gleefully take on more lift and duration with no impact to drivability. In fact if you use the stock 5.0 cam with more CI you will drop your RPM HP curve. You surely will want some type of lift and/or duration changes.

**EagleAutosports** · 08-11-2009

Considering what you're going to be doing with it, I'd highly advise a custom grind cam and they're not that much more expensive than an off the shelf stick.

MUSTANGPAT93 · 08-12-2009

Im a bit worried about the lift on the cams since there isnt much clearence between the roller rockers and the valve covers. I know thats a typical problem with the trick flow heads. I cant use the tall ford valve covers because i will have problems with smog and down want to have to deal with the problem later down the line. Whats the worst possible case if i go with the stock camshaft?

**RLG34750** · 08-12-2009

Quote:

Originally Posted by MUSTANGPAT93

Whats the worst possible case if i go with the stock camshaft?

Not to sugar coated it.......

It will run like a shitzu puppy

a stock cam will not allow the heads flow to satify the needs of additional displacement....

MUSTANGPAT93 · 08-12-2009

Well first off thanks for not candy coating it.
Do either of you have a idea what to do about the valve cover situation?
Will the boost make up for what the cam cant do if i have no choice but to go with a stock cam?
Thanks for your help with this it is much appreciated.

KLWorra · 08-12-2009

I'd be surprised if you couldn't get a fairly mild cam under those, I am thinking 0.550 lift. I would think a duration in the 210/220 range.

I might consider doubling up on valve cover gaskets to build up height. Just thinking, might be crazy.

Dude, you totally need more cam even with SC or other.

MUSTANGPAT93 · 08-13-2009

Thats what they had done prior to me buying the cobra. But i had noticed a valve cover leak and was going to fix it prior to the motor letting go. I talked to a few people regarding the cam and they had told me that the more aggressive cobra cam would be fine for the 331. This information came from the place where i am buying my motor, im not sure if its bs but i would make the assumption he has to know something about what he does.

**RLG34750** · 08-13-2009

Quote:

Originally Posted by MUSTANGPAT93

Thats what they had done prior to me buying the cobra. But i had noticed a valve cover leak and was going to fix it prior to the motor letting go. I talked to a few people regarding the cam and they had told me that the more aggressive cobra cam would be fine for the 331. This information came from the place where i am buying my motor, im not sure if its bs but i would make the assumption he has to know something about what he does.

People are telling you lies.....PERIOD

You will need more than a cobra cam with a N/A 331

Now throw the supercharger in the mix .......

I hate

You need a custom grind cam

Smurf stang · 08-13-2009

I would totally go with a custom grind and your car will thank you. Also with the valve cover I had spoken with Greg at TFS and he said that their standard valve cover would cover my Comp cam gold roller rockers. I haven't put them on yet as the car is getting some interior work done and I am not proficient in that department.

**RLG34750** · 08-13-2009

after reviewing the original post......

it appears you working with a tight budget......

For what its worth .......

you may consider a different direction for your build......

Granted everyone wants big horsepower but there is more to it than just the engine.....

you will need extensive suspension upgrades and using a blower

the fuel system with also need to be upgraded ......

individually the money is not alot but together it adds up quickly i may add......

advice would to reasarch alll the parts you plan to use for compatibility........

and determine the primary use of the car.......

but once again to reply to your orginal question......

for optimum performace a custom cam is the way to go.....

But there are off the shelf modesl that could be use .....

keep in mind you will sacrifice some performance but it would run decently.......

302Feen · 08-13-2009

Quote:

Originally Posted by RLG34750

after reviewing the original post......

it appears you working with a tight budget......

For what its worth .......

you may consider a different direction for your build......

Granted everyone wants big horsepower but there is more to it than just the engine.....

you will need extensive suspension upgrades and using a blower

the fuel system with also need to be upgraded ......

individually the money is not alot but together it adds up quickly i may add......

advice would to reasarch alll the parts you plan to use for compatibility........

and determine the primary use of the car.......

but once again to reply to your orginal question......

for optimum performace a custom cam is the way to go.....

But there are off the shelf modesl that could be use .....

keep in mind you will sacrifice some performance but it would run decently.......

Reggie is right. Building a fast car is more than just building a fast engine. You will need all the SUPPORTING components, such as upgrading the suspension and brakes; and strenghtening the rear end and transmission.

To answer your question about the cam... When you build an engine, you want to do it good and right. Even if that means waiting and saving for the correct parts. Save for a custom grind cam.

The stock cam won't be able to hold up to the extra displacement in the stroker, and then you're adding a supercharger in the mix. There are some "over the counter" cams that would work, but the point is to get something better than the stock cam that will work well for your application.

89coupe · 08-13-2009

Quote:

Originally Posted by KLWorra

I'd be surprised if you couldn't get a fairly mild cam under those, I am thinking 0.550 lift. I would think a duration in the 210/220 range.

The ramp rate of a Cam like that, is very aggressive. Just like the Ford ALpha cams.

Plus its not even close on the duration if those are advertised numbers or .050.

KLWorra · 08-13-2009

Quote:

Originally Posted by 89coupe

The ramp rate of a Cam like that, is very aggressive. Just like the Ford ALpha cams.

Plus its not even close on the duration if those are advertised numbers or .050.

IMHO the advertised durations are not worth taking about.

As for the cam, it is subjective to opinion of course, what is small to me, may obviously seem large to you.

I stand by the 0.550 and 210/220 or so at 0.050 as a good "moderate" street cam for a 331 with the heads he has. But has to be matced to intake, gearing, compression, use, etc. HENCE why I suggest ALWAYS contact a cam grinder and let them walk you through their checksheet to pick the right grind for you.

Contact Jay Allen, Scooter at Comp Cams, or Predator--they will ask a series of the RIGHT questions to help you pick the right cam.