Hey guys.

I am wondering which camshaft I should run with my 350 tpi with the vortec head swap and 1.6 stamped rockers.

I have been told Comp Cams #'s 08-502-8 or 08-304-8, but I want a second opinion before I decide.

I am also wondering if the headers that are on the existing heads will swap over without problems onto the vortec heads.

Thanks guys!

 

It depends on which Vortec heads you have - stock or "upgraded." If you have the upgraded Vortec heads with better springs, you can run a cam with higher lift.

Are you looking for roller cams or flat-tappet? Are you able to do your own custom chips or have a local friend who can? The stock computer will only handle a cam with about 210 or less intake duration and 112 or higher LSA. With a custom chip you can go larger and tune it to make the computer happier.

Yes the headers will swap right over. Its the stock manifolds that dont work with Vortec heads.

 

I'm doing the vortec head "upgrade" for a higher lift cam.

That's just it....I don't understand the difference between the roller cams and flat tappett cams. This is why I need help selecting a camshaft.

Do I need to go with a certain kind of camshaft (roller, flat tappett, etc.)?

NOTE--I'm using 1.6 crane stamped rockers with screw in studs/guides--I read that these rockers provide good lift and are good quality for the money.

 

Anyone??

 

Roller cam used roller lifters. The lifters have somewhat of a roller bearing on the bottom . Flat tappet uses a flat lifter. You need to run a Hydraulic Roller Camshaft for 87 and up blocks. (Well you dont HAVE too) but with your current motor it swaps right in.

 

roller cams are better as far as streetabilty and offer more hp/smoother running. its technical, ur car is a 350tpi therefore u have a roller cam/factory roller block, u would have to get a roller cam to swap in. vortec heads flow a good bit better than stock, ive seen good power with the vortec heads, GM hot cam specs are 218-228, .495/.495 lift with 1.5rr, u will want to use 1.6rr so it bumps lift to .525/.525 that will increase flow etc. vortec heads and the Hot cam/vortec tpi base and upgraded runners will give u 355hp and over 430ftlbs with a stock chip, u would tune it for alil more hp and better driveabilty but it isnt neccessary for the hot cam.

dont forget vortec heads need vortec TPI base., to run a cam with more than .470 lift requires machine work to the heads, so if u use the hotcam u need head work for larger springs. very streetable and thats a 130hp increase over your current stock setup... thats like a 8psi supercharger

 

What do you mean by "factory roller block?"

I am more confused now than I was before.

OK, if I get the GM hot cam and vortec heads (machined and modified)--I want to use the 1.6 crane stamped rockers, screw in studs, and guideplates because these rockers are not self aligning.

I have already drilled the pushrod holes to 1/2" to accommodate the 1.6 rocker pushrod issue.

Is there some lifter issue or other issue that will prevent this combo from working?

I am confused.

 

No, no, no. You CANNOT use an LT4 HOT cam with a stock chip. Not on a MAF car, not on a MAP car. The computer cannot handle the sudden decrease in vacuum from the larger cam and will flood the engine with extra fuel. On my car the engine was so rich it would make my eyes water just standing next to it. See my second post on what works with the stock chip.

The 08-502-8 is 218/224, .495/.503 lift on 112 LSA. That will require a custom chip.
The 08-304-8 is 210/220, .500/.510 lift on 114 LSA. That will work ok with the stock programming, but your heads better be able to handle .550 lift. With 1.6 rockers that lift becomes .533/.544". I would go with this cam IF your heads are modified to accept .550" lift or more. It will idle slightly rouger than stock, but give you about 75-100 more horsepower along with the heads.

 

im sorry idk wat happened with your motor, but CHP did an engine build and i memorized the article bc i wanted to do the setup for yrs. they were able to dyno the engine with no problems with the vortec heads/HOT cam/vortec base/ edelbrock runners/ AND STOCK CHIP!!!!! oh yes with 24# injectors at 43 psi, and a MAF!!

they did say that the engine would pick up more power with a tune to take full advantage of the mods. but many ppl run the hot cam in stock motors with the stock chip, ive seen lumpy cams in TPI 383s running the stock chip still. u can even run the stock chip with the HSR... which is a whole new ball game as far as tuning. maybe ur setup didnt work but it is suppose to work. i also believe in the CHP build they used 24# injectors for more fuel to help with the new found power and air at stock 43psi setting.

ok now for u new2chevy...
year 1987 till now... chevy/GM converts all blocks to factory roller block... that means that the engines from the factory come with roller cams... the blocks are machined for roller cams, roller cams require roller lifters, and the end of the cam has a cam button that keeps the cam in the block u could call it centered. the roller cam also has a different style plate that holds the cam in the engine. internally the engine has longer lifter bores to accomodate the longer roller lifters, in the lifter valley the factory roller blocks recieved a stamped piece of steel thats called a SPIDER that centers and aligns all the lifters correctly so they dont spin the in the bores. also 1987 till now blocks were changed to 1 piece rear seal, and center bolt heads on 350s. basically this means u want to put a hydraulic roller cam in your engine bc its basically a drop in, no mods required, u get a flat tappet and u have to do modifications for it to fit.

dont get stamped steel rockers.... yea they are cheap etc but the rob ur engine of power and create friction/heat. get 1.6 aluminum roller rockers, they are lighter, full roller will give u 15hp gain. i forget which is required but proform makes cheap affordable roller rockers self aligning or non. i got self aligning for mine and i thinnk they cost me 160$

if u get a hydraulic roller cam the cam with bolt right in, u will have to adjust the dowel pin at the end of the cam prob to a certain length for your application but thats just pushing it in. if u want u can reuse ur factory roller lifters, personally i would reuse them if this is just temporary(if they are all good) if u dont plan on opening up the motor anytime soon, i would replace them, get stock replacements, i did from speed pro at like 9$ a lifter... total is kinda$$ at 150$ but now u have new lifters that dont have all those miles on them.

those cams are very mild cams, if anyhting you would want the first one with more duration, more duration will give u more RPM potential and more HP which the vortec heads will like since the heads flow very well for there size. those are almost the same #'s as the hot cam at 218/228. then again u have to modify the heads no matter what for .55 lift anways so throw in a cam and do it right the first time, the hot cam will give more power than both those cams. and ive seen it run with larger injectors and a stock chip with no probs... although it would bennifit with a nice tune for the combo.

oh also vortec heads dont flow any better over .50 lift anyways so to get one of the cams mentioned above that will give u any more lift is pointless bc vortec heads flow best in the .3/.4/up to .5 lift range. and they dont really like porting.

 

That is PARTIALLY correct. MANY GM engines from 1987 did not use the roller cam. MANY of the blocks were either cast without the roller cam provision bosses in the lifter valley. Even more were cast with the bosses, but the bosses were not machined. Only a small portion of the 1987-1995 blocks ran roller cams. From what I have seen, only around 30% of the blocks were actually had roller cam provision and had them machined for a roller cam. Another 10-15% had the lifter retainer spider stands there, but were not drilled and tapped.

 

As a general rule of thumb, the 87-up vette and f-body motors came with the factory roller cams. The 87-up truck motors still got a flat tappet cam. As stated above, all 87-up blocks have the bosses cast in them for the roller cam, but the truck blocks usually don't have the final machining on the top of the lifter bores, or the bosses tapped that mount the lifter guide retainer ("spider").

 

Actually around 1990 or so, most 2500 and 3500 series trucks got the PEANUT roller cam in them.

NOT ALL 87+ BLOCKS HAVE THE BOSSES CAST INTO THEM!!!!!!!!!

 

i meant as a general rule of thumb.... just like in mags where all parts are for past -86 and then 87-present. its a general rule of thumb. im not talking about trucks or airplanes etc, i was refferring to f-bodys bc thats wat his question was pertaining to... his 350tpi. and im betin hes got a roller cam in his 87 camaro 350tpi... tell me im WRONG!!! lol

i have an 87 350tpi and i just ripped the whole top end off to do a headgasket change and i had a roller cam/with spider/ and centerbolt heads.... the only reason i would think that not all 87 cars had roller blocks was bc of GM's buildup of blocks they had to use up... ususally when they change something like that it doesnt happen adbruptly they phase them out.

 

also when i pulled the intake of my 87, it was a roller cam block

 

I've run the hotcam, lpe219 cam and the Comp 218/224 496/502 cam before on the stock 89 chip with no problems. Even passed e-check with it. Running optimal? No, but it ran fine

 

I dunno how you guys have done it. I have done two MAP setups and one MAF setup with the LT4 hot cam and neither one ran well at idle. It required me to tune the chip to keep it from running rich. *shrug*

 

I totally agree dude. Once again, as a general rule of thumb, ALL f-bodies and vettes got the roller cams starting in 87, even the lowly L03 TBI motors. It would make sense that all the f-bodies and vettes produced in those years would only add up to 30% of total engine production. Who the hell cares what the trucks and airplanes got in those years. Lol. I sold an 87+ truck 350 motor a while back. It was cool that it had 4 bolt mains, but since it was a truck engine, it had a flat tappet cam, which made it worthless to me.

 

I don't care what engine CAME in a F-body, do you know how many have their original engine now? Care to guess percentage wise? I am going to say 1/2 have the engine that came in them. The most common swap is probably a truck L03/L05.

 

Yeah, I'll definitely give you that. So many variables, especially on cars that are 20 years old. Guess it comes down to the same thing as when guys determine what rearend gears they have by looking at their RPO sticker. The only way to know for sure is to take it apart and look.

 

One of the best cams you could pick for your combo would be the ZZ9.