6m help

[Nomad707]

i have a spare 7m block and 5m head... is it a bolt on application? do i need to modify anything to get my 5m head onto the 7m?

From what i hear it is bolt on.. but i just want to be sure.

Thanks.


-Ryan

 

[jblaze]

I think that this is the wrong area for that question. Try the 7M (MA70) section.

 

[Tanya]

i have a spare 7m block and 5m head... is it a bolt on application? do i need to modify anything to get my 5m head onto the 7m?

Technically, yes, the 5MGE head will bolt directly onto the 7M block.

Homemade 6M can be made two ways:
5M head
6M/7M block
6M/7M crank (pretty sure the late model 7M crank won't fit into the early 7M block w/o clearancing, same issue as putting it in the late 5M block)
6M/7M rods
5M high comp or low comp pistons
(the 5M low comp pistons will give the 6M a 9.2:1 compression ratio, the high comp pistons roughly 9.6:1 compression)
5M oil pump and xover tube

5M head
85+ 5M block
6M crankshaft (or 7M crank, but 5M block needs minor clearancing for extra balancers)
6M/7M rods
5M low or high comp pistons
5M oil pump and xover tube

and you'll either need to source out a 6MGE crank pulley (VERY hard to find) or use the 7M crank pulley and adapt it. Going to be a horrible bitch read: close to impossible, to run the a/c or power steering with the 7M pulley)

 

[Nomad707]

Technically, yes, the 5MGE head will bolt directly onto the 7M block.

Homemade 6M can be made two ways:
5M head
6M/7M block
6M/7M crank (pretty sure the late model 7M crank won't fit into the early 7M block w/o clearancing, same issue as putting it in the late 5M block)
6M/7M rods
5M high comp or low comp pistons
(the 5M low comp pistons will give the 6M a 9.2:1 compression ratio, the high comp pistons roughly 9.6:1 compression)
5M oil pump and xover tube

5M head
85+ 5M block
6M crankshaft (or 7M crank, but 5M block needs minor clearancing for extra balancers)
6M/7M rods
5M low or high comp pistons
5M oil pump and xover tube

and you'll either need to source out a 6MGE crank pulley (VERY hard to find) or use the 7M crank pulley and adapt it. Going to be a horrible bitch read: close to impossible, to run the a/c or power steering with the 7M pulley)

thank you for the in depth info... Can you elaborate more on the pulley?

 

[Tanya]

Pic comparisons between the 5M and 6M crank pulleys

The 6M pulley has the same inside diameter as the 7M pulley, but has the correct belt ribbings for the 5M/6M accessories.

The 5M crank pulley's inside diameter is too small to fit on the 6M/7M crankshaft. It would need to be machined out, leaving very little material left.

Again, the 7M crank pulley will obviously fit, but you'd need to have thw 7M alternator and waterpump pulley, and even then you may need to space out the wp pulley to align it correctly. I do not know of anyone using their 5M power steering or a/c while using the 7M pulley on their 6M.

 

[Nomad707]

i am not going to use power steering or A/C... so is there any bolt ons for my use???

Im going to use a 7m complete bottom end (jdm with 40k or less miles) with a rebuilt 5m head. Im using the 5m head for flow, and for something different. (and because i have the block with little miles ready for it)

BTW im looking for a ok shape 5m head if anyone wants to trade for a 7m head.

 

[Tanya]

JDM with 40k miles is fairly meaningless, at least to me anyway. Still a junkyard motor that more than likely needs rebuilt.

Again, there IS A BOLT ON crank pulley, it is the 6M pulley which I already mentioned is very rare. The 5M pulley can be machined to fit. The 7M pulley fits, but needs other 7M pulleys as well.

 

[turbodriz]

5m head flows better than the 7m head?

 

[Nomad707]

its not useless... sorry i forgot to state i checked through it and replaced the rings.

Thanks for the help... And Hopefully ill get some pics soon.. im having a hard time locating a front clip for this beast.. gotta find some fendors and bumper. and hood. lol.

 

[Nomad707]

5m head flows better than the 7m head?

Thats debatable.. but i beleive that it is much freer flowing then the 7m.

Take a look at 5m Valves.. they are pretty much comparable to a Small block V8.... They are pretty big.

The 7m's exhuast flow is quite horrible stock.

 

[turbodriz]

I have more questions but this in the wrong section. Can somebody please move it?:cry:

 

[Nomad707]

this is in the proper section.... its 6m and falls unfer other engine tech.

 

[turbodriz]

this is in the proper section.... its 6m and falls unfer other engine tech.

Oh.... Alright what is the difference between freer flowing and flowing better?

 

[turbodriz]

Thats debatable.. but i beleive that it is much freer flowing then the 7m.

Take a look at 5m Valves.. they are pretty much comparable to a Small block V8.... They are pretty big.

The 7m's exhuast flow is quite horrible stock.

Have never seen a 5m head. Do you have pics? Do they make aftermarket valves and other head components? If this is the case why don't people who are building there 7ms for high hp not use 5m heads?

 

[Ma70.Ent]

I think I remember talking to Tanya about this, and IIRC, she said the 7M head > 5M head in flow.

JDM motors are hit and miss, mine definitely was, but good luck with yours.

 

[Tanya]

Bleh. I don't even want to get into the 5M vs 7M head debate. For me, using the 5M head is a personal preference. I don't want to deal w/ the wiring issues and don't really like the look of the 7M head and cam covers and all that.

5M head:

And just to say, I don't think I've ever seen someone flow a 7M head vs a 5M head and put up actual flow rates and whatnot. People say the 7M head outflows the 5M, but I can't recall ever seeing real data.

 

[turbodriz]

Those valves are huge. I still don't know even though there so big if it will out flow 12 more valves.

 

[Nomad707]

my dad says from personal exp the 5m flows better... ill try to see if he has data

 

[annoyingrob]

my dad says from personal exp the 5m flows better... ill try to see if he has data

If you look at a 6M-GE vs a 7M-GE, the 6M has less horsepower, but more torque.

The heads are definitely different, I wouldn't call one better or worse though.

 

[Tanya]

If you look at a 6M-GE vs a 7M-GE, the 6M has less horsepower, but more torque.

The heads are definitely different, I wouldn't call one better or worse though.

And you know that how? Dyno sheet comparison? Let's see it.


I don't think I've ever seen a bone stock 6MGE dyno sheet. The numbers I have seen vary so much and all are at different levels of modification. Hp ranging from 155whp to 171whp. So, not having a stock 6MGE dyno sheet to compare w/ a stock 7MGE dyno sheet, I am unsure how people are coming about the 6M has more tq than a 7M. This is twice I've heard this in the past few days...