hush777 Posted January 10, 2005 Share Posted January 10, 2005 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 Quote Link to comment Share on other sites More sharing options...
[HTi]Johnson Posted January 10, 2005 Share Posted January 10, 2005 I know people who used a carbed block in place of a turbo block. There is a risk of shiz breaking Due to the compression. But this car went 200+miles, rally-ed, and went another 250+ miles back home. No problems at all. So why not keep the turbo? [HTi]Johnson Quote Link to comment Share on other sites More sharing options...
naru Posted January 10, 2005 Share Posted January 10, 2005 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. Quote Link to comment Share on other sites More sharing options...
ShawnW Posted January 10, 2005 Share Posted January 10, 2005 Just don't run it very hard or you will blow the pistons into pieces. Quote Link to comment Share on other sites More sharing options...
naru Posted January 10, 2005 Share Posted January 10, 2005 Just don't run it very hard or you will blow the pistons into pieces. Why? No turbo. Quote Link to comment Share on other sites More sharing options...
hush777 Posted January 10, 2005 Author Share Posted January 10, 2005 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 Quote Link to comment Share on other sites More sharing options...
naru Posted January 10, 2005 Share Posted January 10, 2005 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?" Quote Link to comment Share on other sites More sharing options...
calebz Posted January 10, 2005 Share Posted January 10, 2005 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. Quote Link to comment Share on other sites More sharing options...
canajun2eh Posted January 10, 2005 Share Posted January 10, 2005 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. Quote Link to comment Share on other sites More sharing options...
hush777 Posted January 10, 2005 Author Share Posted January 10, 2005 I said "Why? No turbo."(re piston destruction) not "Why no turbo?" Just no turbo short block around right now.... Hush Quote Link to comment Share on other sites More sharing options...
calebz Posted January 10, 2005 Share Posted January 10, 2005 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? Quote Link to comment Share on other sites More sharing options...
WoodsWagon Posted May 4, 2005 Share Posted May 4, 2005 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? Quote Link to comment Share on other sites More sharing options...
85Sub4WD Posted May 4, 2005 Share Posted May 4, 2005 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 Quote Link to comment Share on other sites More sharing options...
wagonist Posted May 4, 2005 Share Posted May 4, 2005 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. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.