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Carbed block in Turbo wagon without a turbo??


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Just thinking about this.

I have an 86 carbed wagon that is not worth fixing, but the engine/trans (d/r) are good. Also have an 85 turbo wagon with a bad bearing (so the guy says).

Am thinking, to eliminate the compression issue and also give my old lady a 4x4auto which she wants (but has a lead foot so skip the turbo power) of putting the carbed block in place of the turbo block and redo the exhaust to what would be on a non turbo wagon......

Will the computer handle running things ok without the turbo?? Just in MPFI mode?

 

Hush

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Just thinking about this.

I have an 86 carbed wagon that is not worth fixing, but the engine/trans (d/r) are good. Also have an 85 turbo wagon with a bad bearing (so the guy says).

Am thinking, to eliminate the compression issue and also give my old lady a 4x4auto which she wants (but has a lead foot so skip the turbo power) of putting the carbed block in place of the turbo block and redo the exhaust to what would be on a non turbo wagon......

Will the computer handle running things ok without the turbo?? Just in MPFI mode?

 

Hush

 

I think this would work fine.Swap distys too.You`ll also want to swap the transmission vacuum modulator to a non-turbo one.

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Why? No turbo.

 

Turbo blocks are (I think) 7.5 : 1 compression and I don't have an extra around or the resources to redo the one in the wagon right now. Carb blocks and also the rare mpfi non-turbo blocks are 9.0 : 1 so I could just change the heads out from the turbo engine and use the short block from the carb engine. That high of compression in a turbo situation will result in lots of detonation and possible engine damage... melted/cracked pistons... blown head gaskets from to much pressure.....

 

Hush

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Turbo blocks are (I think) 7.5 : 1 compression and I don't have an extra around or the resources to redo the one in the wagon right now. Carb blocks and also the rare mpfi non-turbo blocks are 9.0 : 1 so I could just change the heads out from the turbo engine and use the short block from the carb engine. That high of compression in a turbo situation will result in lots of detonation and possible engine damage... melted/cracked pistons... blown head gaskets from to much pressure.....

 

Hush

 

I said "Why? No turbo."(re piston destruction) not "Why no turbo?"

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Turbo blocks are (I think) 7.5 : 1 compression and I don't have an extra around or the resources to redo the one in the wagon right now. Carb blocks and also the rare mpfi non-turbo blocks are 9.0 : 1 so I could just change the heads out from the turbo engine and use the short block from the carb engine. That high of compression in a turbo situation will result in lots of detonation and possible engine damage... melted/cracked pistons... blown head gaskets from to much pressure.....

 

Hush

So I guess I'm in trouble with my carb shortblocked turbo motor with the TD04 on it eh?

 

BTW, Turbo motors are 7.7:1. I was under the impression that the Carb motor was 8.5:1. Anyone here with an 87 FSM that could give me a definite answer? My 88 and 89 FSMs don't have any carb info.

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Carb specs are the same as SPFI, compression-wise.

 

I don't see any reason why you couldn't use a short block from a carbed engine, mated to the MPFI/Turbo gear from your defunct engine. I agree with you, that you shouldn't run into any longevity issues if you disable the turbo.

 

Better still: Remove the turbo completely. That would improve exhaust flow, giving you a tiny bit more power. As near as I can tell, the turbo doesn't provide any meaningful input to the ECU. The ECU would just see zero boost.

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Carb specs are the same as SPFI, compression-wise.

That doesn't make any sense.. My books say SPFI is 9.5:1

Pistons between carb and SPFI are different part numbers

EA82 CR is based completely on piston shape.

 

Does anyone out the have an 87 FSM with carb info in it?

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  • 3 months later...
I was under the impression that the turbo were the lowest compression engines, the SPFI were the highest at 9.5:1 and the carb's fell in the middle.

Will the mpfi turbo intake manifold bolt up the the cab heads though?

SPFI (1989 FSM) - 9.5:1 (domed - so I'm told)

Carb/MPFI N/A (1985 FSM) - 9.0:1

Turbo (both) - 7.7:1

 

MPFI turbo intake will NOT bolt to carb heads - either need to run carb manifold or swap heads

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If you use the block & bottom end, exhaust from the carb, with the heads, inlet manifold, air flow meter from the turbo should be ok.

 

You'll have to block the water & oil pipes to & from the turbo though.

 

don't know how the mapping of the turbo ECU will react to higher revs but no boost reading. Might go into a "limp" mode.

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