Hey Guys,

I have been enjoying looking over the forums since I joined a couple weeks ago. However, this was always one of the forums I turned to when I was looking up things for my TPI.

After much reading, and much thought, I think I a close to choosing the parts for my top end (Intake, heads, cam).

I currently have heddman headers, to high flow cats, 2.5" exhaust to dunomax mufflers. From what I have read, this is one of the first things people say to do to the TPI motors. Also, I have a ported lower manifold, and plenum, but I might move to a ported Vortec lower manifold.

Now, I understand that the TPI will not be a high RPM screamer. It was designed to build torque, and power usually falls off in the upper 4k range. Thats fine with me. I do not intend to race this where high RPM's are important. I drive it in the summer, and like to have legal fun. I don't speed, but I do find myself taking highway on-ramps quite a bit

So, back to my build.

For heads, I think I will go with a performance vortec pair. Money is an issue with this, and I found these for $735, shipped. I like these heads, because they offer more lift over stock Vortec's, in case I do decide to go with a HSR or something in the future, and want to go with a high RPM cam.

http://www.jegs.com/i/ProMaxx-Perfor.../2151/10002/-1

Now, with going with the Vortec heads, I need the Vortec TPI base:

https://sdparts.com/details/scoggin-...-center/sd3816

Ok... The cam. This has given me the most headaches. There are so many grinds, I want to make sure that the one I choose is the correct one. Also, do I convert to roller? My engine is an early '86, so I have flat tappet. Converting it seems expensive, and probably unnecessary. After pouring through forums, this cam is brought up alot:

http://www.summitracing.com/parts/cca-cl12-268-4

Please feel free to offer opinions, and any changes you would make. Also, sorry if this reads like a book, I'm just trying to offer as much information as possible. Thanks!

 

well your base looks like it's set up for an egr valve, and the heads appear to lack an egr (heat crossover) passage...so you'll have an issue there right off if the vehicle has to be smogged

second, that's a mighty small cam (0.480 inch lift)...fine for oem heads that max out at around 0.488 lift before coil bind or valve seal interference becomes an issue....so if I was paying for aftermarket heads already set up for greater valve lift, I'd rethink the cam selection

Since of the removal of zinc from lube oil because of environmental concerns, with a flat tappet cam, I'd only use a lifter that has the lifter base drilled with a tiny hole to provide forced lube to the cam lifter interface

 

Thanks mtwoolford!

EGR is not an issue. I'm from PA, and they just do a gas cap check.

From my understanding, and please correct me if I'm wrong, the more lift the cam gives, the further along in the power band it will make power. With the TPI not flowing that well past 5k, I do not want to sacrifice the low end torque for HP, if I cant spin the motor to make it.

Now, with the port job I'm having on the intake, I'm sure I can gain a couple hundred more RPM, but I have to choose a cam that will be happy in the RPM range this engine can make.

This is exactly why I'm having a headache with the cam choice

I am also aware about the zinc. I know they make an additive for the oil because of this. I'll have to look into what will be better in the long run. I wish I had a post '87 motor, so I had a factory roller haha

 

read this first
http://www.superchevy.com/how-to/97458/

I have a set of vortecs. Spent an additional 1,000 bucks for the manifold and runners that fit those heads. Add in your 375 bucks.. you can buy better aftermarket heads. Not sure if your 86(E) valve covers work,,vortecs are center bolt covers. Rockers are not guided, but have a lip on each side, keeps them where they belong. Springs do NOT give you a lot of options toward cam choice, to much lift, crush the valve seals.. Comp cams make a "Beehive" spring for the vortec that gives you a lot more choices..get the keepers too. Forget what the springs and valve gear cost me, plus the beehives, plus the Scropion roller rockers.. getting the idea? AFR 95s will go along way towards your goal. BTW, vortecs are the best buy/flowing heads GM has put out for the gen.1 SBC.

 

Thanks for the heads up ghoastrider1!

So, for the money, It would be better spend on a good set of aftermarket heads that will fit my intake.

Any opinions on a Cam? Thats where I am really really stummped

 

on the comp cams site they offer a few TPI cams, but you gotta look for them.. post a thread asking about cam choice... you will be overwhelmed with advice but most like 2 or 3 cams. I myself bought a summit cam as I too have no intention of taking my engine past 5 grand, but do enjoy a on ramp,lol.

 

Lt4 camshaft has been a proven upgrade with the Vortec heads and Scoggin Dickey TPI Vortec manifold and made 356hp on a dyno.

 

http://www.superchevy.com/how-to/eng...-tpi-manifold/

 

Thanks Z51breeder.

I believe the LT4 Cam is a roller unit. My engine is an '86, and came from the factory with a flat tappet cam. I would have to convert over to roller, which is expensive. However, there are benifits of going roller.

It all comes down to the cost.

Im in a pickle, because I know that I can build a decent 350 from a junkyard motor and swap meet parts. However, I like the TPI, and I enjoy making power out of the engine that is in the car.

You get to feel the before and after effects.

I am going to start a thread on cam choice, and see what everyone says.

Thanks Everyone!

 

In the long run converting to a roller cam is the way to go.You can always keep an eye out for a good used short/long block with a factory hyd roller cam.