So I've got a carbed ea82 for sale. I found another member on the board who would like to purchase it, but we're not sure if it's compatible with his 88 XT(ea82 mpfi). Seems to me like he could just swap his entire intake over onto the carbed longblock? Might there be compression issues? Or problems with the ecu(different sensors and such)?

 

Thanks ahead of time for any clarification!

MPFI = Multi Port Fuel Injection, dual port heads.

 

SPFI & carbed are single port heads, here anyway.

From what I know (that's the easy way of saying I'm not sure and probably shouldn't even bother posting) I think the intakes are interchangeable. I'm pretty sure the main difference in the motors is the pistons and the compression ratio. SPFI is higher compression (9:1) and carbs are lower (8:1). I *think*

Ohhhh MPfi....durf.

Hmm, so this guy said his engine developed a knock, which is most likely in the crankshaft area right? So he could potentially use my short block and use everything else from his current engine?

Hmm, so this guy said his engine developed a knock, which is most likely in the crankshaft area right? So he could potentially use my short block and use everything else from his current engine?

Yep!

Good news! Thanks Bruce

hold the bus !

 

What about a carb block not having the rear turbo side breather for PCV, at the back of the mpfi blocks behind the flywheel is a baffled plate that leads up to the top of the block with its outlet near the knock sensors threaded hole? Carb blocks generally did not have the whole extra passage did they ?

Maybe I need to get more clarification about this guys engine. It's not turbo. Is MPFI only used on a turbo setup? And perhaps his engine is SPFI?

Should not be an Issue at least for the bottom end,The MPFI engine differs only in two significant areas , MPFI and Higher Compression.

After a number of years in the real world compression changes with the wear and tear affecting volumetric efficiency so that does not really matter and the Manifolds however will be different as the carb model heads are single inlet port and the MPFI heads are dual port like the Turbos.

 

That is why the Single point Injection can be retrofitted to the EA81 but the MPFI heads are like the Turbo EA82 and have dual inlet ports so Carb manifolds will not fit therefore the heads are different and must be swapped out to use a carb engine in that application or find a carb manifoild and muck around with the ignition and remove the MPFI wiring, That woulkd be harder and more time consuming than mating a good bottoim end with serviced MPFI heads, Your call as to the cost benefit ratio but the Bottom end will work.

Maybe I need to get more clarification about this guys engine. It's not turbo. Is MPFI only used on a turbo setup? And perhaps his engine is SPFI?

 

A Very few GL-10s in 85 had Non-turbo MPFI.   All  GL turbos are MPFI........and all XT engines,  turbo and N/A were MPFI.......it came with 7.7:1 ratio pistons in turbos, and 9.5:1 in the N/A. 

 

Carbed bottom end can be bolted to MPFI heads for use in the XT.....however.....PCV port at the back of the block will not be present on the Carbed block....so some PCV routing will need changed.  Carbed pistons will be 9:1 ratio instead of 9.5:1  but that is negligible difference.

 

Otherwise....the shortblocks are identical.

Edited May 25, 201411 yr by Gloyale

Also the turbo dual ported heads have different Cams for a different valve overlap duration..