zz4 and TBI

[bobracing]

Can I make the stock '88 Chevy TBI work with a ZZ4 (355hp) engine?
Got a friend with the zz4 sitting in his shop, I got an '88 Blazer (350/210hp) in need of a non-smoking engine.

I know the chip will have to be changed, I'm also thinking the injector will probably need to be bumped up, any recommendations?

I've seen some talk about sealing to the manifold, did I remember this right?

Anything else I'm missing?

 

[Binder]

Can I make the stock '88 Chevy TBI work with a ZZ4 (355hp) engine?
Got a friend with the zz4 sitting in his shop, I got an '88 Blazer (350/210hp) in need of a non-smoking engine.

I know the chip will have to be changed, I'm also thinking the injector will probably need to be bumped up, any recommendations?

Not familliar with a ZZ4 but if it has a distributor then the short answer is yes.

I've seen some talk about sealing to the manifold, did I remember this right?

What do you mean? Sealing the TB to the zz4 manifold?

 

[GaryTJ]

I think the zz4 motor is a performance crate motor that is set up to be carbed.

The easiest way would be to use a big block adaptor from a 4 bbl manifold to the TBI. They are a factory piece that was used in the late 80's. available in the wrecking yards for cheap.

That and a few sensors and a dist pulse and hook up the TBI. Easy!

 

[bobracing]

Yes, the zz4 is a 350/355hp chevy crate engine.
And Yes, the engine was carb'ed.

So, if I steal the dizzy out of the current engine, get a 4bbl adapter off a BB chevy, transfer all the sensor, and burn a chip for the new power band, should work?

 

[GaryTJ]

yes, it will work.

be sure and change the dist. drive gear to a hardened one or the warranty is voided and it will chew the cam.

call chev for part #

 

[jeeptech 1]

Not Completely sure but The Cam in the zz4 engine hasthe Duration and centerine WRONG. The Compurtor Won't like the valve overlap. If you put it in an injected motor Change the cam to a low cam duration camshaft .See crane cam web site or comp cam web site .Good info.

 

[GaryTJ]

The regular cam is not too bad, you might have to use a restricter in the vacuum line to the MAP. The motor has a slight lope at idle, but not bad.

The "hot" cam is a goner for the computer for sure.

 

[jeeptech 1]

This isthe zz4 cam spec's (reg.cam)part#10185071 Hydraulic roller tappet
Crankshaft Duration @ .050 Tappet Left (Degrees)
I:208
E:221
Max Lift W/ 1.5;1 Rocker Ratio
I:474"
E:510"
Zero /Zero _ Valve Lash
Lobe Centerline (Degrees)
112
This is the Reg. Cam not the HOT cam
as you can see the Duration overlap And centerline is set up for a carb an and high stall convertor or an stick shift vehicle.with carb.

A TBI vehicleneeds a cam with a Centerline Lobe Of 115 to 116 Degreesand a duration EqualOr very close in degrees to each other .Like the 383Roller cam engine(196I-206E)
So I feel the Factory (reg) cam won't work.

 

[Binder]

The factory cam will work it's just a matter of how well. Easiest thing to do would be to just replace it but if you try it out you may just have it idle in open loop or maybe be full time open loop....There's a bit more to the chip then what you describe. You most likely won't be able to just drop in a chip and have it work great. It's a bit of trial and error involved.
If you plan to do this yourself I highly recommend you get one of these ECMs.
http://www.dynamicefi.com/