Rear limited slip type?

[RET_COP]

Brent, enlighten me, with due respect, I have read your posts. It would be obviously cheaper to change the intake, are you suggesting a Victor Jr.? If I were to change the cam, what would you recommend? Am I close to the horsepower I stated?
I'm assuming it was installed straight up, but these are the things that bug me
and thanks for your interest.
Just for more info, Tremec 3550, 3.27 gears, cam had advertised duration of 286/296
Lou

[blykins]

Well, here's the way I usually tackle an engine build:

Figure out what rpm range you want to run in, what characteristics you want the engine to have, etc., then choose components to fit that bill.

A hydraulic roller camshaft with advertised durations of 286/296 probably has a .050" duration of 236/246. A 236° camshaft in a 351W with good heads probably peaks at around 6200-6400 rpm if the springs will let it. If your hp peaks at around that rpm, then that means you would have to shift about 400-500 rpm higher than that if you were running the car hard in order for the rpms to fall back into the peaks everytime you shift.

Just going off of the information that you have given me, your heads are flowing well, you have a higher rpm camshaft, and you have a dual plane intake that is basically centered around an operating range of 2000-6000 rpm.

That intake will probably work just fine, but it's not really paired correctly with the other components....that's my opinion as an engine builder anyway.

If you're more of a cruiser and not a leg-stretcher, I would change the cam to something with a shorter duration at .050"...maybe a 224-230 degree camshaft. This would put the peak at around 5700-5800 and would enhance the low/midrange manners.

If you're more of a leg-stretcher and not a cruiser, then I would definitely consider throwing a Vic Jr on the engine. You would lose a little streetability, but towards the mid to higher end of the curve, it would pull harder.

If it were my car, I'd change the cam. A taller gear like a 3.27 isn't really suited for long camshaft durations. I think you'd really notice some difference just driving around the neighborhood with a shorter cam. Your tuning efforts would be less and I think your throttle response would be crisper down low.

My guess is that you're close to 425-450hp.

Even if you kept everything the same, I would at least take a look at dialing the cam ahead. I would venture to say that the LSA is a 110....and if you cranked that thing down to about 106 ICL, you'd see a noticeable difference at lower rpms, vacuum, etc.

[RET_COP]

Brent, again thanks for the reply and information.
I failed to say that it is a flat tappet cam and I do not have the cam card. I'm going by notes on paperwork.
I do cruise alot but hammer the car from time to time ( just can't help it). I don't live above 6000rpm.
Are you suggesting advancing the cam 4* when you say 106*ICL, meaning moving the Intake CL toward TDC? I'm sure I would have to check valve to piston clearance, which would require head removal. This would also take away the rough idle that I really like.
What is your opinion on the thumper/voodoo type cams that have short LSA. Is there a place for them on a motor that is looking for torque and good mid range?
I will eventually dig into this motor and do it my way, but for now I need a good year of crusin' before I inform the wife that my perfectly good running car needs to be taken apart
Lou

[blykins]

Yes, advance the cam to a 106° ICL. (If it's a 110 LSA...which we really don't know. You may need to put a degree wheel on it and check out the actual specs.)

You don't have to pull the head to check piston/valve clearances. Just pull an intake and an exhaust valve spring off, replace them with a checking spring, then use a dial indicator to see how far you can push the valve down until it touches. You will also need a degree wheel for this as you need to check the clearances where the valves would be the closest. For the intake valve, it's usually from TDC to 10° ATDC, where the intake valve is trying to chase the piston down on the intake stroke. The exhaust valve is usually closest 10° BTDC to TDC, where the piston is chasing the exhaust valve back down to the seat.

The only idle quality that you'll see a change in is how clean it idles, how well it takes gas down low, etc. Overlap doesn't change when you advance/retard cam timing.

The Voodoo cams are nice. Usually tighter LSA's narrow the range a little. When it comes time to go through it, you can give me or one of the other builders a call and we can help you pick a cam that will meet your needs perfectly.

If you do plan to go through it later on, I'd probably just drive it and enjoy it for now.

[RET_COP]

Thank You very much Brent, no more questions sir, your time is appreciated, I will be talking with you again
Lou