I have been running a GM847 cam for a little while now , but I allways thought that a custom cam for my 383 would give me better results.

Anyway I apply for one and do several programs to see what would be the best for my car.

Each one I have come accross looks like a tweaked GM847...lol

For example here is one (name of company witheld)

.050 dur 237/240 lift w1.6s 285/295 112 lobe sep

Whne you look at the actual timing of the cam the LSA are quite different as are the opening and closing points. Would this cam make any difference over the GM 847?

If you want I can later post the exat timing figures.

My set-up which will not likely change except for the converter and heads is
3700 pound car (97 WS6)
383 with 10:1 compression AFR 190 cc heads (will be ported in future).
stock ported intake, 58mm t/b, 1 3/4 hhoker LT headers, mufflex Y, 3 inch cat-back (have cut-out for track) 3000 vigilantee converter,3.73 rear gears.
30 # injectors (going to 36s this winter). and thats the meat of the stuff.

Any thoughts?

 

How streetable do you wanna keep it? Your 10:1 CR isn't helping ypu much either. Who's gonna do your heads?

 

I would imagine it would make a difference, but how much of a noticable one is the question.

 

Well I want it hydraulic, and I drive it about 3 miles a day...lol

I know the compression isnt the best for power, but beggers can't be choosers (i got the stroker kit dirt cheap)

With the GM847 it runs mid 11s @ 116 -117 mph.

I plan on having lloyd do the heads in the near future.

 

Just get Bret to make you a custom cam. Its cheap and he knows what he is doing.

 

I've got several specs from several companies. All are extremely simular (within 2 to 4 degrees in the timing itself)

 

I'll buy everything except the 'cheap' part.

The cam price may be competitive, but you may need better/different valvetrain parts to make a custom work well.

 

Ive got a pretty good handle on the valvetrain part of it, I plan on getting fresh springs and pushrods when I swap, but the set-up I have now see's 7000 rpm pretty regularly.

 

Well yeah thats true, but the price of the cam isn't much over the price of an off the shelf cam. I don't want to discuss the price and get him in trouble but lets say its affordable.

 

perry theres no reason it should allready produced a good number... i think its lacking in the heads area for sure are they just outta the box AFR's....

hell mines got a shelf cam and stock castings ported also and you see the results of mine but then mines also got 12:4.1 comp which is also a factor

 

Jeff ,the AFRs are pretty well stock, the only difference from how they left the box is a new valvejob (2 years old) and blending where the CNC ended and the rough cast begins. On The flowbench that gave it another 5 cfm almost all the way accross the board, it flowed if I remember right 267 @ .500 on the int side.

I am planning on next year building a forged shortblock with 11.5 :1 compression. But in the meantime I may put the Mr Gasket .026 head gaskets on to give me another .2 or so. The Pistons I have have a -18 cc dish in them, block is undecked.

 

Oh I forgot to add the actual timing events..


GM 847 cam timing @.050 Intake- opens 10 deg BTDC ,closes 44 deg ABDC max lift is at 107 deg ATDC.
Exhaust- opens 58 deg BBDC ,closes 4 deg ATDC max lift is at 117 deg BTDC

3 of the programs yeilded a cam extremely close to following specs..

Intake valve opens 11.8 BTDC ,closes 47.2 deg ABDC Max lift is at 108.5 ATDC.
Exhaust valve opens 56.2 deg BBDC ,closes 4.2 deg ATDC max lift is at 116 deg BTDC.