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Discussion Starter · #1 ·
I am building a 6M from scratch parts for my friends 84 MK2

here is the details... pics are following soon

the block crank and rods are from a 7MGTE while utilizing a 8.8:1 stock cast 5M pistons 0.020 over.... the short block is all assembled while using Clevite 77 main/rod bearings... the aluminum timing cover is from a 5M and the cover hole for the crank snout needed to be machined bigger to fit the larger 7M crank snout. basically this is a 6M engine but by using a 7MGTE block... a oil squirter would be in use to cool the piston bottms for added performance.

any sugggestions and comments are welcome.

the engine is not yet done due to the 5M head is still on the stock 5M we are using right now...

pictures is on the process for poeple who wants to make a hybrid 6M from cratch parts they have...

I would like to thank Mike Lewitz for inspiring this project... for he made me think and ponder for the effoert he did to make bolt up a 7MGTE bottom end and 5M valveterrain
 

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I have a completely rebuilt P+P head for sale, I went the 7MGTE route. It has all new valves, guides, cams, lifters, rockers and 3 angle valve job. If you are interested.
 

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well, ill be doing this soon, but im going high compression n/a. what you want to do is use the lower 7m timing covers. they are the same as 6m. you will use the 7m crank pulley. the ribbed belt will go around the water pump, alt, and crank. then the power steering belt will go from the water pump to the power steering pump. it will require a pretty short belt. use all the 7m timing gears and a 7m timing belt. btw, those 8.8:1 compression 5m pistons will make that motor 9.2:1 compression as the pistons move up higher in the bore with the 7m crank and rods. the alt braket should bolt to the 7m block and you will use the front motor mount holes in the block. if there is anything else you need to know feel free to email me.
william
[email protected]
 

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Discussion Starter · #6 ·
well thank you for all the response...

sloopercat... thanks for the head offer but I have different plans for the head built up.

and William, thanks for the heads up for the compression issues... thats why I went with the 8.8 CR pistons from the earlier model 5M we will be using a 2mm HKS MHG and we will be using the 5M aluminum front cover just have to dremel the front cover for the larger crank snout hole.... as for the puleys it will be all 5M.... the 5M crank pulley has been machined already to retain the AC and PS.
 

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The lower timing covers (inner and outer) are exactly the same between the 5 and 6M. From what I remember I used both the orginal 5M cover on my 6M when I rebuilt it. From what I recall the 7M rear lower cover is a little different than the 5/6M one around the water pump. You do need to remember to use a 7M front main seal with the 6/7M timing cog (the ID is bigger). The 8.8:1 pistons will give you 8.8:1 compression with the 5M head one. Piston pin location is the same. If it isn't you are screwed the pistons come flush with the block deck at TDC and the clearance is the HG thickenss (maybe .030" compressed or so?), so they can't go up much higher.
 

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really, i was led to beleive that the 6m's had the early 5m pistons that were flat top and still had the compression of the later domed style? and i recall the 6m water pump being the same as a 7m also.
william
 

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Oops my mistake, yeah it would be 9.2:1 with the flat top domes (just like a 6M :twak:). I'm thinking 5M crank in a 7M :drinking: . I just can't seem to get that concept out of my head :pat: .

I could be wrong on the 7M timing cover. Its been a while since I've looked at one.
 

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Looking in the EPC Toyota has different #s for the 5 and 7M rear lower covers. 11301-43020 (or 43010) and 11301-42010. Water pump has a different part # as well (outside shape and bolt pattern look different in EPC).
 

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im pretty sure eric had to buy a 7m water pump for his 6m awhile back. ill try to call him tommarow and ask if he doesnt chime in first.
william
 

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williamb82 said:
really, i was led to beleive that the 6m's had the early 5m pistons that were flat top and still had the compression of the later domed style?
william
The 8.8:1 pistons from a 5M yield 9.2:1 compression in a 6M. You are compessing more displacement into the same space at TDC,... = 9.2:1
Ihth,
Jamie
 

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The 8.8:1 pistons from a 5M yield 9.2:1 compression in a 6M. You are compessing more displacement into the same space at TDC,... = 9.2:1
Ihth,
Jamie
yeah, we had already figured out i was right. he was thinking a 5m crank in 7m block. :p
william
 

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Discussion Starter · #14 ·
the 5M and 6M rear timing cover is the but only one difference.... the crank hole is bigger on the 6M to have clearance and provisions fo the bigger 6M crank snout... that is why the 6M and 7M has the same front main seal... as for the waterpump from the 6M and 7M... I am not sure but the water pump I have used on m 6M when I rebuild it... I have used the 5M water pump... 7M has a different water pump design... but not totally sure... can some what match this parts up....

as for the headgasket... I am using a 2mm HKS MHG to lower the compression for turbo duties... this should lower it down to about 8.5-8.8:1 with the flat top pistons fro the 5M...

I would be taking some pistures of the short block this afternoon and hope to get it at the forum tomorrow night....

Later...
 

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Discussion Starter · #15 ·
here's the scop on the engine after rigorous hours of doing nothing for the past few days... we have finally got the 84 head on the shortblock and now had everthing in the it except the intake manifolds and we are just waiting for the 60-1 turbo from the turbo shop. everythign is doing well... the engine as expected as a non interferance engine is still a non interference engine.

the only thing left out is the 5m crank pulley to be machined for the larger crank snout and the 60-1 turbo we are still waiting.

Jay
 

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3000cc MK2 said:
the 5M crank pulley has been machined already to retain the AC and PS.
Can you tell me what you had done in the way of machining?
I took a 5M pulley to a local machinist and was told there wasn't enough metal around the keyway.

I am also looking at doing this swap as 6M engines are rare here in New Zealand.
 

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Discussion Starter · #17 ·
toymad said:
3000cc MK2 said:
the 5M crank pulley has been machined already to retain the AC and PS.
Can you tell me what you had done in the way of machining?
I took a 5M pulley to a local machinist and was told there wasn't enough metal around the keyway.

I am also looking at doing this swap as 6M engines are rare here in New Zealand.
We have just got the 5M front pulley fromt he machineshop and it is kinda thin on the walls and he had no chance to mahince the keyway due to he has no broach to use for the key way but you can machine down the key in the crank to fit it when you have the pulley machined to fir the larger 7M crank snout.

Jay
 

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you need that keyway. its absolutely neccesary. otherwise the pulley wont line up right and you wont be able to set the timing belt right.
william
 

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I think he was impling that the keyway is still there on the pulley after the machining, its just alot less deep and the key needs to be machined to fit in the smaller space. So does the machined crank pulley still look safe? And is there enough room to cut the key way deeper still? The one thing that worries me about machining the key down is weakening its grip on the crank. I know enough people that have had keys destroy themselves and\or the pulley and crank with it with stock specs. Most of those were due to loose crank pulley mind you but its still something to worry about. I think I may have to dig up a 6m crankpulley part number and see if a local dealer can order me one.
 
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