Choosing A Cam Shaft

[1badmustang]

Ok so here's the back ground on my car 2.1 kenne bell supercharger port and polishing the heads, hooker shorty's, flow master exhaust, H pipe, dyno tuned
Blow a head gasket and the cars in pieces now thinking about putting a comp cam 270HR in while it's apart any other suggestions the car is an automatic

 

[toyman]

That's the cam in my combo based on the engine builders recommendation. I thought the 284HR might have been another choice but was told that the idle would be quite lopy. The 270HR has a solid idle at 850 rpm.

 

[1badmustang]

Thanks that's good to know, I'm really trying to get around 400rwhp the car previously spun the rollers at 360rwhp but was all stock just with the supercharger bolted on and 12lbs of boost

 

[Gearbanger 101]

Talking camshaft in the singular, instead of plural.......quoting grinds like 270HR....284HR

Where are you guys getting these camshaft numbers? Unless I'm missing something, a 270HR is a Windsor OHV cam and I don't even see a 284HR listed for a modular engine? Are you sure you aren't confusing these with a Windsor based 302/351 engines?

The closest I can find in Comps listing to either of those cams is the XE270AH....which seems like a nice streetable cams, but will require ECU tuning a valve springs to accompany them. Count on dropping over well over $1,000 if that's the case.

Have you considered any other cam manufacturers as an alternative. Crower seems to have a pretty popular cam set up at your level of performance for the 2V crowd?

Ford Modular Camshafts - Camshafts

 

[1badmustang]

It's the cam grind number listed on comp cam's web site the actual part # is 35-310-8 listed for 1985-1995 EFI cars

 

[Gearbanger 101]

It's the cam grind number listed on comp cam's web site the actual part # is 35-310-8 listed for 1985-1995 EFI cars

My mistake man, for some reason, I had 4.6L SOHC engine in mind when I read 2.1 Kenne Bell in your description and saw the pic of your car. Guess I should have looked at which forum I was in.

 

[1badmustang]

It's all good the car is a 1995 GT love the good old 302

 

[1badmustang]

I was also thinking of putting some roller tip rockers in also just standard 1.6 I'm not real sure if just porting and polishing the heads and a camshaft is going to net me another 40rwhp or not, not real sure how much power roller rockers will free up

 

[Gearbanger 101]

I was also thinking of putting some roller tip rockers in also just standard 1.6 I'm not real sure if just porting and polishing the heads and a camshaft is going to net me another 40rwhp or not, not real sure how much power roller rockers will free up

In all honesty, if it were me, I'd put the money into a good set of aluminum heads, over a camshaft and rockers at this point. Actually, if it were me, I'd do all three....but you may not have the budget to play with?

Still though, there's no better excuse to change the heads than when you've got them off. Even the most wildly ported stock heads can't match the performance potential of any of the out of the box aluminum units. A good set of GT40X, Edelbrock Performer/Performer RPM, AFR 165's or Trick Flow 170's will probably get you closer to your goal and make power over a broader range than a camshaft swap at this point.

Also, not sure which manifold you've got (stock, or GT40 based) but that's going to be your real limiting factor after the heads. Its really too bad Kenne Bell didn't design these kits to be used with a better flowing lower manifold. If you've got the stock lower on there, I'd say save your money and put it back together the way it is....even ported, the stocker couldn't possibly keep up to the airflow demands of the blower, a good flowing set of head, or camshaft for that matter. The GT40 lower is better, but not by leaps and bounds. A head upgrade would help, but there's really no need to go any bigger than the heads quoted above, or a the camshaft you're looking at....because the lower manifold will never support airflow anyway.

 

[1badmustang]

Yeah it's the stock manifold I'm not really sure what other manifolds will bolt on to the kenne bell 2.1 I'd like to build a better motor later but that's down the road I'll find another 302 block and go from there while the car is up and running

 

[jozsefsz]

I'd suggest the rockers not necessarily for power or anti-friction / heat benefits, but because the stock rockers are pretty flimsy. Mine warped enough after a few years of turbo use on a stock cam to have excessive lash and got very noisy. That's not only bad for the everything valve related including the cam, but it was no doubt leaving some power on the table. A new set of stamped steel rockers vs. new roller rockers you probably wouldn't notice much of a difference, but a worn set of stamped steel vs. new rollers you probably will. Crane makes a set of pedestal mount 1.7's that clear the stock valve covers on the SN95 302's with no interference.

 

[Gearbanger 101]

Yeah it's the stock manifold I'm not really sure what other manifolds will bolt on to the kenne bell 2.1 I'd like to build a better motor later but that's down the road I'll find another 302 block and go from there while the car is up and running

Kenne Bell sold the kit with both the stock and GT40 manifold as an option. Quite honestly, you're gonna have a heck of a time seeing anywhere close to 400rwhp with that stock manifold unless you're running a steady diet of race gas and/or water methanol injection. Just too much heat and not enough airflow to make the power.

If I were you, I'd see if I could get a hold of another stock lower manifold and have it sent out to be welded and ported professionally. The 1 and 5 runners of the stock manifold are huge bottle necks and need to be heavily modified in order to move the required amount of air. It's too bad Kenne Bell ever released that kit with a stock manifold design.

To be totally honest, I think you're ahead of the game as it is if you're putting out 365rwhp already.

 

[1badmustang]

It spun the dyno at 360rwhp 12lbs of boost

 

[Gearbanger 101]

It spun the dyno at 360rwhp 12lbs of boost

I'm gonna guess that was a single run, after a cool down on a fairly mild day unless you're running around with the aforementioned tank full of race gas, or spraying water methanol.

Spinning the blower that hard, through that top end without additional octane in the tank, or the use of an aftercooler will take its toll in the form of massive heat soak. I'll bet after hot lapping the engine, that power figure drops by 40rwhp.

I"m not trying to talk you out of getting the camshaft, or the rockers, but I'll bet you aren't rewarded with near the horsepower gain you hope to achieve from it, simply because of such elevated ACT's and the inefficiency of the rest of your set up.

 

[1badmustang]

94 octane pump gas with NOS octane booster also, not race gas, 3 pulls on the dyno all within that same number

 

[90lxwhite]

94 octane pump gas with NOS octane booster also, not race gas, 3 pulls on the dyno all within that same number

I spun the rollers with stock heads, a .512 lift cam, ported HO lower, and the Vortech v3 6-8 lb kit on 93 octane, and it made 332 at the wheels. I think the bulk of your power came from the 12 lbs of boost you were pushing through. The ported heads helped some but I don't think as much as the boost.
I'm betting that if you were to go with a "larger" cam that you might pick up like 10 or so hp but you won't make the 400 rwhp mark.
If money is an issue I'd put everything back together and dial down the boost so you don't blow another head gasket and run it as is.
If you're looking to make 400 to the wheels you're gonna need better heads and a good tune. I cam will gain a little but the e7's ported or not are still kinda crappy. If I were you I'd get with the tuner and say, "hey, why'd you give me a tune that'd blow my head gasket!?"