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Discussion Starter · #1 ·
hey whats up everyone.
i have a couple of freinds with a mkIII that are wanting to destroke it. they flat out traded me my old 5m block for a 7m block in good shape. they removed the crank on the block because that was the only thing they wanted was that and the conecting rods. well i am just curious of what you guys think about this and also they were wanting to know if there were any stronger connecting rods for the 5m because the current ones are to weak for the stress they plan on putting them through.

thanks ahead of time for your input.
 

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The 7m block is no better than the 5m block, unless you are going turbo. If they wanted to destroke their engine, they'd be using the 5m crank and rod combo, making it a 2.8 liter. Assuming your 7m block is in good shape, you'll be able to take advantage of the oil feed/drain ports, and oil squirters. The physical dimensions on the two blocks (including deck height) are basically the same, except for some differences in external casting. Put some ARP rod bolts into the 5m rods, have them resized, rebushed, balanced, shot peened, etc, and they'll hold plenty of power. Take care.
-Aaron
-edit. The 7m rod bolts do not fit a 5m rod.
 

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ok, droping a whoping 5mm of stroke isnt worth that much trouble imho. thats less then a 1/4in and isnt gonna allow the engine to rev that much more. ive looked into it and i personally think its pointless. now if they could use the 4me crank which is yet even shorter, it will prolly be square or over square and "might" be worth it. but for a 5m crank, i dont think so. very good trade on your part if you plan on going 5mgte or 7mgte. use that block.
william
 

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Discussion Starter · #5 ·
thanx for the replys. ill let them know what they need to dew to the rods and all but this is just a side project for them.

by the way i began dismantling the 7m block last night and it was easier than i thought. we got all the postons out and about to start on the crankshaft before i realized it was 11.30 and i had a thirty min drive to get home and school today so i called it quits. that block is a lot easier to take apart than what i thought. its just going to be fun putting back together after we get it back.

the block is for a future project of mine to have a 400+hp 7mgte mkII. i dont have the funds to do everything so im keeping the block at a freinds house so i can work on it over there and keep it out of the weather.

is there anything i should look out for while dismantling the block. the guy that gave it to me sad it had a few miles on it meaning it was well broke in but he yanked it because it had low oil psi but not drastically low. im thinking its the bearings that were starting to go.

i have a ? though. should all of the numbers and everything match up on the conecting rods and such because if so i believe that this block had been rebuilt previously.

anywho sorry about the drabbling on im just thinking out loud. thanx for the help
 

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No the #'s on the rods are not always the same but the rods should stay at its previous location. In other words rod from cyl #1 should stay with cyl #1, etc. IIRC, the #'s on the rods, crank and block has to do with main bearing sizes and cylinder bore sizes. You need to get a TSRM and it would explain what #'s correspond to what size bearings and pistons were used WHEN the engine was assembled at the factory.
 

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Does the 4ME have the same main and rod journal sizes as the 7M,.. and what is the stroke difference between the two? (Metric and standard,.. I'm an old schooler here..lol)


Scotty
 

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Come on guys,.. Any of you that have a MKI, I KNOW you have a repair manual, and it should give you the main and rod journal diameters in there somewhere. :D I've become really curious in this thought of using a 4M crank into another block if it would make a feasible combination. And since I happen to have a 4M in my MKI, it would be a waste if there was good reason to put it to use, and let it go instead. MkI'ers, lets do osme homework! 8)


Scotty
 

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Let me see what I can find from the MKI Haynes manual. I "think" I have a Toyota 4ME engine manual lying around, but I can't remember. The 5ME manual may not help much here.
 

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Scotty,

Turns out I do have a Toyota 4M repair manual, but it did not list the connecting rod journal size, just the main journal. Unless I was looking in the wrong place :?

Fortunately, the 79 - 81 MKI specific Haynes manual has all of the information that you need. This is what I came up with.

Crankshaft Main journal diameter: 2.3617 - 2.3627 inches (59.988 - 60.012mm).

Connecting Rod journal diameter: 2.0463 - 2.0472 inches (51.976 - 52.000mm).

Bore - Stroke on a 4ME: 3.15 x 3.35 inches (80.0 x 85.0mm).

Anybody have the above specs for a 7M?? I don't have this.

P.S. Do you have the firewall dataplate info yet on the Silver 80??
 

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M series cranks come in 3 sizes:
- 75mm: M, 3M
- 85mm: 2M, 4M, 5M
- 91mm: 6M, 7M

As you can see, if you want to build an oversquare 7M the 4M crank won't help you. However if you can track down an M crank, you'll end up with a 83x75mm engine which will give you a swept volume of 2435cc, or about 2.4 litres. Methinks you'll have to rev that engine pretty hard to keep up with a normal 7M!
 

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Dang it CJSREDPRA, I've been going for the last few days (possibly weeks) knowing I was forgetting SOMETHING! I'll take pics today, but I wont have anyway to get them to show on here. Do you have a way to host them? I'd really like a break down of what both the '80 and '81 had to say. :) I'll send them too you a little later this afternoon. Send me your regular email addy in a PM so it'll save me from trying to upload on here. Pics will be there shortly!


Scotty
 

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Does anyone have specifics on bearing sizes for these donor motors? I have been looking for days to find hard info on the 5mge, 7m, and other L6 toyota motors, but rarely come across credible info, and none to confirm it. So far i have come up with this

7mg(t)e-
wrist pin: 18mm
con rod: 52mm
crank bearing: 60mm
Con Rod Length: 152mm

5mge-
Wrist pin: 18mm
Con Rod: 52mm
Crank Bearings: 60mm
Con Rod Length: 155mm

1ggte-
wrist pin: 18mm
con rod:42mm?
Crank bearings:55mm?

Also found this thread on the forum which is nice. http://www.celicasupra.com/forums/showthread.php?12741-5M-6M-7M-Rod-Lengths-How-Big-is-Yours
 

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All i can say is completely ignore the 1ggte... not worth your time. Unless one gets dropped off on your doorstep like a baby in a basket, don't even bother looking into them.
 

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Fair enough. I was considering it because they are such a short stroke, but couldnt confirm the dimensions of the crank. I dont want the motor. I was just looking into the crank and possibly con rods to destroke an extra 5m I have in my shop. I just want to find some good hard numbers. There seems to be a lot of advice, but not much in the way of concrete calculations and specs on the less popular motors and parts.
 
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