unknown_host

iTrader: (1)

I have a set of like new Vortec heads in my garage that I purchased on Craigslist. I have done a few searches on here, in particular I found this article:

http://www.camaroperformers.com/cama...l/viewall.html

Where a mostly stock TPI, SDPC vortec base 350 makes 305 horsepower by swapping to Vortec heads with the stock cam.

I have a 1989 Iroc Z with L98 and 90k miles on it. I was considering purchasing the Edelbrock Vortec base and putting the heads on my stock shortblock.

Any advise on this? I didn't find a whole lot of threads with results in them on this. I know that the Vortec heads flow about 40 cfm better than a stock L98 head, and the low lift #'s are great as well. If I did this, I would probably even leave the stock camshaft in since the shortblock has 90k miles on it and I wouldn't want to mess with piston to valve clearance.

Thanks in advance!

Jim85IROC

iTrader: (2)

The mileage of your motor has nothing to do with piston to valve clearance. You'll never have PTV issues with a cam that's mild enough to work with TPI.

There aren't a lot of guys with a lot of good things to say about the Vortec TPI setup, but I think that for a street car, it'll make a good combination. I hope I'm right, because I'm doing one right now myself. The big bottleneck with a setup like this is the lousy flowing SDPC/Edelbrock intake base, and there's not really much that can be done about it, but as long as you build the rest of the combination to optimize performance at lower RPM, I think this can still be a good combo. While you have the motor apart, I'd definitely think about adding a cam. The stock cam sucks, and a nice mild cam can only help with new heads.

unknown_host

iTrader: (1)

Thanks for the reply, definitely let me know how it turns out. Where did you find your manifold, I can't find one for much less than $480...

unknown_host

iTrader: (1)

Would I make more power with the stock TPI and a different set of heads that flow similar to Vortec heads?

I suppose if I have to invest nearly $500 into a manifold, I could sell my Vortec heads and put that money towards a new set of heads that would fit the stock TPI setup.

1bad91Z

iTrader: (1)

If you are going the vortec route, with a good set of runners and port your plenum, you can make enough power to have some fun...

I use the cc503 cam in my motor

unknown_host

iTrader: (1)

Out of curiosity have you dyno'd your setup or run it at the track?

Jim85IROC

iTrader: (2)

I bought the SDPC (Skoggin Dickey) manifold used. SDPC sells it new for $400. It's identical to the more expensive Edelbrock manifold.

To answer your question about power with other sets of heads, generally, yes, with any set of good flowing aftermarket heads and an aftermarket base & runners, you'll probably make more power than with the Vortec setup. I went with the Vortecs because I already had the heads. If I didn't already have them, I never would have gone this route. By the time you get vortec heads that can handle any kind of cam, and buy the SDPC base, you're really not saving much money compared to a set of Trick Flow 180s and an accel/TPiS base, which will yield better results.

unknown_host

iTrader: (1)

I already have a new set of Vortec heads although I realize they will need to be modified for the increased lift. I didn't realize the SDPC intake was $80 cheaper, it seems like the general consensus is that the intake with a set of Vortec heads on a stock shortblock should make about 300 horsepower with the stock ecu and throttle body, does that sound right?

unknown_host

iTrader: (1)

Also will you be using the external EGR or ditching it altogether?

Abubaca

iTrader: (3)

I've done so much reading on this subject it'll make your head spin. I really wanted to see what could be done with such an efficient vortec head, especially on a TPI. Most of what I read really shows people mismatching intakes, exhaust, cams, etc. etc. I was hoping to build a much milder vortec motor (than most) but had hoped it would perform up there with the "bigger" mismatched combos that I see so much of. .....however....at the end of the day, the Vortec manifold just turned me off to it. I didn't want to match the whole engine around a the most expensive part, which has NO moving parts, yet was the bottleneck of the whole operation. That manifold just really turned me off.

That being said, I'm also a fan of the idea of putting down the mouse, turning off the computer and just enjoying what you have. That being the case, I think a vortec head TPI, even with that manifold would really be enjoyable on the street.

unknown_host

iTrader: (1)

I completely hear what you are saying, I am more doing my research so I don't make any mistakes. I feel like I am Vortec heads, a roller cam, and a carb and intake away from 400+ horsepower and I am trying to talk myself out of that route. But just the price of a Vortec TPI intake is about what it would cost for a good dual plane intake and carb, plus I could sell the TPI setup at the end...

Jim85IROC

iTrader: (2)

Agreed. What drove me to do it was that years ago I lucked into a set of like-new SDPC- modified vortecs too cheap to pass up. Fast forward 7 years and I have the 350 out of my IROC because I'm putting in a 403 LSx, and I have a high mile 305 in my GTA. As a result, I decided to do a no-budget swap for the GTA. Because all my money is wrapped up in the LS swap, I had to limit myself to a grand or less, with the emphasis on "less". That really killed the chance for aftermarket heads, so it left me with vortecs fed either by TPI or HSR. I decided that the TPI would suit me better on the street. Like you had planned, I'm keeping it mild. I'm keeping my 214/224 cam but I bought some 1.6 roller tip rockers to raise my lift. My mild build should maximise torque and make a great running car. I've got a build thread going in the engine swap forum if anybody is interested.

LilSki

iTrader: (1)

I just finished a vortec TPI build in my 85. I went with an LT1 cam and SLP runners. I did get the block for free but it needed a new crank and bearings all around as well as rings. Including the intake I spent around $1000 on the motor. I am very happy with the end result as it has way more power than the 305 that was in there and I haven't even finished tuning it. I also swapped in a T56 which was also around $1000 so for about $2000 I got a fresh motor and trans.

watajob

iTrader: (29)

I remember reading a while back that due to the diminishing demand, one foundry churns out all the TPI bases now and just casts in the appropriate name. I got screwed out of $350 by a crook in SC, (along with a few other people here and on corvetteforums), over an older, original, Accel base. That was a few years ago when I started to gather parts for the build and was doing research on the subject. I do know for a fact I had to open up the ports on the base where it meets the tubes and I have a TPIS Bigmouth base and their long tube runners, so I believe there's some validity in that story.

Jim85IROC

iTrader: (2)

I'm not sure I'm familiar with the back-story of the TPI bases. Since I bought my accel back in the early 2000s, I mostly stopped paying attention. I do know that those old accel bases seem to be in mighty high demand now though, but I decided that I'm holding on to mine. I can't imagine that I won't wind up with another TPI small block down the road.

TTOP350

iTrader: (8)

Does anyone know the flow numbers on the different bases?
SDPC
Accel
Edelbrock
stock.
maybe we should have a flowbench party with them..

Abubaca

iTrader: (3)

I think one of the guys socal guys did flowbench them fairly recently. ...I've seen the thread, but I'm not sure exactly which one it is.