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Engine Swap Help!!!

1K views 7 replies 3 participants last post by  tomslik 
#1 · (Edited)
I recently purchased a 1986 Camaro IROC-Z, Z28. It has a 305 TPI engine with a 700R4 trans. I have a carbuerated 355 built for another project that I want to put into this Camaro now. The motor in the Camaro is the stock 305 190hp TPI engine (not the H.O). The 355 is a 350 bored .030 over, with a mild cam, 2.02 fuelie heads, pete jackson gear drive, torker 2 intake, & holley 600 cfm carb. My questions are:
Should I convert the car over to run the 355 carb. motor or swap the intake & heads off the 305 to make a TPI 355?

How would the TPI swap affect my compression, hp, and performance?

Any and all info. and comments would be appreciated.
 
#4 ·
crazytown said:
I recently purchased a 1986 Camaro IROC-Z, Z28. It has a 305 TPI engine with a 700R4 trans. I have a carbuerated 355 built for another project that I want to put into this Camaro now. The motor in the Camaro is the stock 305 190hp TPI engine (not the H.O). The 355 is a 350 bored .030 over, with a mild cam, 2.02 fuelie heads, pete jackson gear drive, torker 2 intake, & holley 600 cfm carb. My questions are:
Should I convert the car over to run the 355 carb. motor or swap the intake & heads off the 305 to make a TPI 355?

How would the TPI swap affect my compression, hp, and performance?

Any and all info. and comments would be appreciated.
only way the compression will change is if you drop a screw down one of the ports;)

put a timing chain in it,larger injectors and probably a 350 MAF (if they're different), undoubtably a rechip of the puter..

after reading closer, are you sure it's tpi rather than tbi?
 
#5 ·
Info Update

The motor in the Camaro is the 305 TPI (tuned port injection) 305ci, 190hp engine (RPO LB9) The 305 TBI (throttle body injection) was used in the Z-28's from 1982-1984. In 1985 Chevy came out with the famous IROC-Z, introducing the TPI system taken from the Corvette.
The compression ratio will increase when the 305 heads are put onto the 350 block. The 305 heads have smaller combustion chambers then the 350 heads. There are many factors that can change compression ratio, combustion-chamber volume, the deck height (the height of the piston above or below the block deck), the head-gasket volume, and the piston design that will either add volume (a dished piston) or subtract volume (a domed piston) from the combustion chamber.
In an article about a 305 TPI to 350 TPI swap the changes needed include:
bigger injectors,
Knock sensor,
ESC (electronic spark control) if equipped),
ECM (depending on year),
and PROM (programmable read only memory)
 
#6 ·
crazytown said:
The motor in the Camaro is the 305 TPI (tuned port injection) 305ci, 190hp engine (RPO LB9) The 305 TBI (throttle body injection) was used in the Z-28's from 1982-1984. In 1985 Chevy came out with the famous IROC-Z, introducing the TPI system taken from the Corvette.
The compression ratio will increase when the 305 heads are put onto the 350 block. The 305 heads have smaller combustion chambers then the 350 heads. There are many factors that can change compression ratio, combustion-chamber volume, the deck height (the height of the piston above or below the block deck), the head-gasket volume, and the piston design that will either add volume (a dished piston) or subtract volume (a domed piston) from the combustion chamber.
In an article about a 305 TPI to 350 TPI swap the changes needed include:
bigger injectors,
Knock sensor,
ESC (electronic spark control) if equipped),
ECM (depending on year),
and PROM (programmable read only memory)
true, didn't see the thing about swapping heads.
and that brings me to why would you swap heads?
a little creativity on the center bolts on the intake and you got it...
 
#7 ·
Update.....

The reason I am debating about swapping the heads out is because the heads on the 350 are the older type "fuelie heads" which are no doubt good heads for performance, but are made from the older engine technology for running on leaded gas. There is a risk of burning out the exhaust valves of old technology engines if operated with unleaded gasoline in heavy constant service. This is because old technology engines relied upon the lead in the gasoline to coat and protect exhaust valves from the extreme heat of the exhaust.
 
#8 ·
crazytown said:
The reason I am debating about swapping the heads out is because the heads on the 350 are the older type "fuelie heads" which are no doubt good heads for performance, but are made from the older engine technology for running on leaded gas. There is a risk of burning out the exhaust valves of old technology engines if operated with unleaded gasoline in heavy constant service. This is because old technology engines relied upon the lead in the gasoline to coat and protect exhaust valves from the extreme heat of the exhaust.

want to know what I'D do?
i'd run 'em 'till they needed a valve job,THEN worry about it.

what casting # on the heads?
if they have accessory bosses, chances are they've been induction hardened...
 
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