[89tSupra]

Can someone tell me exactly what a 6m-GE is? I am familiar with the 7m and 5m but not the 6m. Is this a 5m head on a 7m block? I know that the early 7m's had cranks with 6m stamped on them. If this is the case could I use the head from a 6m on a 5m? A 5m head on a 7m block?

TIA

 

[Voyn]

Yeah, the 6M is basically a 7M block with a 5M head. More or less. Pistons are the same as in a pre-84 5M, with what appeared to be 7M connecting rods. Rings, main- and rod-bearings from 5M fit. You will need the oil pan and pump from a 5M if you want to stick a 6M in your MkII Supra, since it comes with the center sump pan/pump rather than front sump. Oil pump pickups are not interchageable with the 6M, so you will need a complete 5M pump.

Also, the 6M has no EGR system, so there are only two vacuum lines needed (if the car does not have to pass smog inspections). If you want to use the 6M head on a smogville car, you will have to swap over the EGR pickup from the rear of the head, and use the 5M intake manifold, since there is no mounting spot for the EGR on the 6M manifold.

You can use a 5M head on a 7M block, but you will either have to change pistons or machine the ones you have. The 5M head has two valves/cylinder, while the 7M has 4, thus the pistons for the 5M only have reliefs cut for two valves. Your best bet will be to buy a set of *PRE 84* (non dome type) unless you really want a 9.6:1 compression ratio (a guess)and feel like messing around with possible clearance problems.


Phew. That's a lot longer than I had planned, but there ya go

lemme know if I need to clear anything up, or if you have any other questions....


Vern
6M-GE w/ported head
7M-GE injectors
aluminum flywheel
pacesetter header / 2.5" exhaust

 

[89tSupra]

Thanks for the response. So if I read correctly the head is exactly the same as a 5m (minus egr) and using it on that motor would not cause me problems. The only differences deal with the lower end. So I would also take it that the 5m and 6m share the same hg but the rear seal would be the same as a 7m. I wonder if one could use the 7m head on a 6m block? If the torque band is better why havent those in search of power tried a 6m swap in their mkiii. Thsi might appear to be stupid questions but I am just curious. I have to replace a head on a low mileage 5m and have a 6m on the way. I am wondering if I should just use the head off the 6m on the 5m and then keep the 6m block for a later project. One more thing, are the head bolts the same as the ones on the 7m? Cause if so I wouldnt reuse them. If they are different then maybe. Thanks for your time and tolerance

 

[Voyn]

>>
Thanks for the response. So if I read correctly the head is exactly the same as a 5m (minus egr) and using it on that motor would not cause me problems. The only differences deal with the lower end. So I would also take it that the 5m and 6m share the same hg but the rear seal would be the same as a 7m.
>>

No problem... And yes, in fact, I am using a 5M head on my 6M block right now. Exactly the same, as far as I can tell. I forgot to mention seal differences... you will need the front main seal from a 7M, but the rear seal appeared to be the same, so I used one from a 5M. Head gasket is the same.



>>
I wonder if one could use the 7m head on a 6m block?
>>

you could, but you would have to change pistons so the valve reliefs matched. Really, this would be the same as a 7M, so you might as well use the whole thing, unless you just happen to have a spare 7M head laying around.



>>
If the torque band is better why havent those in search of power tried a 6m swap in their mkiii. Thsi might appear to be stupid questions but I am just curious.
>>

Do you mean a MkII? If so, then more and more people on the Yahoo list are doing just that. If you do mean a MkIII, then I don't see why people would do that, because as far as I know, the 7M puts out more power than the 6M, due to the 24 valve head.


>>
I have to replace a head on a low mileage 5m and have a 6m on the way. I am wondering if I should just use the head off the 6m on the 5m and then keep the 6m block for a later project.
>>

Sounds good to me, because I had to have the 6M worked on before I put it in the car. We got most of the engine apart, and then checked out the cylinder walls. Though most of them were shiny and pretty (you could still see a good amount of the factory hone marks), there was a good sized spot in the #4 cylinder wall that was water damaged. Looked like just discoloration, til I ran my fingernail over it, and it caught a little. So, I took it to a machine shop and had them hone it, re-ring it, and install all new bearings. The bearings still looked good, but these motors have been sitting for years, and you might as well change em. Another thing the guy noticed was that some of the piston rings were quite stuck to the pistons.

so my recommendation is to go ahead and stick that 6M head on the 5M, and re-work the 6M block in your spare time. Keep the EGR blocker plate and the intake, and then stick them on whenever you get around to playing with the 6M. But that's just me


>>
One more thing, are the head bolts the same as the ones on the 7m? Cause if so I wouldnt reuse them. If they are different then maybe. Thanks for your time and tolerance
>>

Since the head is the same as on a 5M, 5M head bolts are required. I got all 14 from Jeff Watson (see the "parts" page here if you have not talked to him before) for $35 or so. Just don't forget to order new washers as well, I did! hehehe. For that much, it's cheap insurance.


glad to help
Vern