I found a guy locally that regrinds your stock camshaft, to just about anything you want. So going with the theory that bigger is ALWAYS better, I went with a 292 duration, and a .515 lift. I know this may be a bit much for factory heads, but I am trying to think about later, when I put vortecs, or aluminum heads on. I did do some gasket matching, and a little porting, as well as shaving them. If I crunched the numbers right I should be aroud 10.25:1. So with that cam, 58mm throttle b. adjustable fuel reg., And a custom PROM, it should tare ***? I havent finished this set of upgrades, but soon as I do you will all be the first to know.

1991 1LE Z28, the last time i ran it at the track it had 1.5 rollers, edelbrock headers, full 3'' flowbie set up all the way out to the 3'' guns,gutted air box, k+n, air foil, and a so called chip. do not be fooled by Hyper tech, its crap. Oh yeah, 2500 stall, fully manual valve body 7oor4, with some bald *** tires, best run was a very traction deficant 13.91@98mph.

 

Assuming you're running stock or large tube runners and the 292 duration is at a tappet lift of .004 or .006 it's a total mismatch. You'll kill the low end and mid range and never crank up top because of the heads and intake. The bright side is you'll kill enough low end to really improve the traction situation. Do yourself a favor and install a cam that's designed for TPI or whatever induction and heads you're running. You won't regret it.

 

I mainly based those numbers on my desktop dyno program. It ''says'' that I should see 425hp/trq. I dont think this program is the authority on the subject, but a pretty good bet. Would a mini-ram set up be more for this cam I wonder? Anyway if it dont work out, I'll pull it and have it reground. Thanks for the input.

 

That cam would run MUCH better with a Miniram or LT1 intake. It's still pretty large for that application too. If you want to keep the TPI, look at the proven grinds like the Accel 74211, Comp XR264, GM ZZ4, or TPIS ZZ9.

 

Excuse me, but how do you REgrind a camshaft to make it bigger?

It's like.... putting a triangle in the square....

I suppose you could hack off the tip of the lobe to make the duration longer, but its not going to lift at all?!

Is it just me, or is this a bogus idea?

 

I dont know if I can explain it well enough with out scribbling on a piece of paper. The easiest way is to weld on the lobes and machine,or grind it down, most commonly done for lawnmower aftermarket cams (go-karts). For my application you grind the bottom of the cams lobe. Or I should say the cams bottom side of the lobe. And gring it in such a way that you make the lobe steaper, faster, thus creating more lift. Probaly doesnt make sense, it didnt to me until I saw it happen. This guy is the only in oregon that does this. I do have there phone # if anyone wants to have it properly explained.

 

MYBLUZ
WHY run a reground cam?
cams are relatively cheap to begin with
factory cams are frequently made with flame hardened lobe surfaces to help prevent wear
regrinding the cam requires you to run custom length ,longer than stock pushrods and new lifters, youll most likely spend MORE MONEY just on the custom length ,longer pushrods than you saved on useing a reground cam!
AND THAT reground cam is ore likely to wear!

if your running a tpi intake that has an effective flow range in the 1500rpm-4500rpm range and install a cam designed for the 3000rpm-6500rpm range youll loose low rpm torque with no possiable return in the 5000rpm-6500rpm range due to the extremely restrictive TPI intake,

YOU MUST GET THE VALVE TRAIN GEOMETRY CORRECT!
heres a simple way to get close to the correct length
BUY ONE OF THESE


http://www.jegs.com/cgi-bin/ncommerc...67&prmenbr=361

after making sure the valve springs are correctly installed you drop the checker in place on the rocker stud and install your adjustable pushrod
adjust the length to fit and measure the resulting length if its within twenty thousands of the stock length its fine for most applications, if its more than 30 thousands long or short get the closest length set available

btw, if your one of the people that still does not own an adjustable push rod! you can easily make your own by cutting a stock pushrod in 1/2 (2 pieces), removeing 1 inch from the total length an then with about 2 " of a 4 inch section of 3/16 or 1/4" thread rod installed and (in one section epoxy it in place leaving about 2" sticking out thread two nuts onto the thread rod and slip on the other end of the cut pushrod,(no epoxy) use the two nuts to adjust to stock length and let the epoxy harded in the one section now you can easily measure and order custom push rods useing the pushrod checker and adjustable push rod as tools
AND YEAH IT ONLY WORKS WITH THE CYLINDER HEADS ON AND THE INTAKE REMOVED BECAUSE THE HOLE IN THE CYLINDER HEAD that GUIDEs THE PUSH ROD WON,T ALLOW THE NUTS ON THE ADJUSTABLE PUSHROD TO PASS THRU, UNLESS YOU PLACE THE CUT ABOUT 1" from the UPPER END OF THE ADJUSTABLE TEST PUSHROD BUT I prefer to place the adjusting nuts centered as I like to watch for all clearances with the intake manifold removed while manually checking as I turn the engine over by hand durring assembly, and at that point, while checking all the clearances, I use test springs which apply very little load on the push rod


http://www.jegs.com/cgi-bin/ncommerc...72&prmenbr=361

HERES OTHER TOOLS YOU MIGHT NEED








SOMETHING TO READ
http://www.compcams.com/information/Products/Pushrods/

CCA-7705 5.800 in. to 9.800 in. adjustment range, Master pushrod length checker 4 piece kit ... $78.69

here

 

Because its only $50 to $75 to regrind, compared to the $260-$300 after market cam. And no I dont have to run longer pushrods and new lifters. And to correct myself the cam specs are exhaust and intake duration is 234 deg. @ 0.50 tappet rise, and a .515 lift. This cam is almost exactly the same as a crane cams TPI cam thats operating range is 2000 to 5500. And who cares if it wears quicker? If it flatens a couple of lobes, ( hard to believe with a Hyd. roller) I pull the whole thing a put a real motor in it. Its all for fun.

 

That cam is still too big for your setup though.

 

There are reasons to regrind a cam, even to increase the lift and duration of the stock cam... but thats usually done when there arent any cams available. The SBC cams are dime a dozen on just about any street corner.

That said, I dont think there will be any problems with it from regrinding it... I know of too many motors running around with lots of miles (and flat tappets) on regrinds, and they are fine. With a roller cam... something tells me its fine.

 

Where are looking for cams at? You can get a cam and lifter kit from summit for under $200.

 

a hydraulic roller and lifter for under $200? I guess I didnt see any rollers for that amount. At any rate 50 bucks seams better at least to my budget. Would you say that its too much for the stock tpi (58mm thr. bod.), or would the heads be more the problem. Or is both. Basiclly I'm trying see what you all think I need to run that cam. Because its not back together yet, and I am not in a hurry. Money is the only factor, so if I can I will do something diff. Anyway thanks for the input.

 

yeah, its $50 for the cam, gaskets, chain, labor.
get it wrong.. itll cost your twice, plus the new cam.
reducing the base circle of the cam is how a "regrind" works.
but youll have valve stem errors, rocker issues and binding if the
geometery isnt correct. so you get to buy some cool tools, because
$50 for a cam is cheaper....
its not a budget to do something twice is it?
dont you think the cam of the TPI has been researched to the
fullest in its 18 years of existance?
you think a reginder has all the data from say crane/comp/LPE to
grind all the neatos into it.. if so hes working too cheap.
blow the $50, let us know how good it was...
when it doesnt work... let us know that too...
airdeano

 

The heads will limit your HP but the stock TPI restricts airflow at higher RPMs which is what that cam is designed for so they kind of conflict with each other. You would be better of with an HSR or Miniram if you don't need to worry about smog

 

AS I STATED THOSE SPECS WERE DERIVED FROM AN ACUAL TPI CAM COMP. CAMS OFFERS. It stated rpm range fit where I want to run. As far as the chain and gaskets.. thats not the issue.I found a mini ram for a reasonable price so I will be going getting that. As for the head issue, I'll cross that bridge later. I have also decided to sell my newly aquired eprom programer in favor of a commander 950 set up. But its $900 tag means the car is down a little longer..... Thanks:rockon: