7mgte pistons and crank in a 7mge?

[Pozobyt]

I have an 89 n/a supra, and recently my harmonic balancer came loose, and messed my crankshaft up.

I have a spare 7mgte motor, could I drop the crank out of the bottom of the n/a motor, and just replace it with the turbo crank? are there any size differences?

I don't want to just do a motor swap because I don't have a wiring harness, or ecu or any of the turbo parts.

 

[whitemike]

If I'm not mistaken I believe the crank is the same in both motors, however the pistons are most definitely different compression ratios. If you decide to just do the turbo swap I have a spare ECU and many other stock 7MGTE parts for sale.

 

[stevenr816]

There's different gen cranks, but stroke doesn't change. They all fit the same.
Rods are the same.
Pistons are different, different compression but nothing that's going to kill you.

 

[shaeff]

Pistons are different, different compression but nothing that's going to kill you.

This is misleading. Swapping turbo pistons (8.4:1 CR) in a N/A car (9.1:1 CR) is going to make that car an absolute slug, amongst other problems if not properly tuned for it.

Read: don't do that and stay N/A.

 

[Nick M]

The clearances on the crankshaft are select fit. GE or GTE has nothing to do with it. And as long as it is apart, get pistons with more compression. 9.5:1 if you plan on adding boost later.

 

[Poodles]

I have an 89 n/a supra, and recently my harmonic balancer came loose, and messed my crankshaft up.

I have a spare 7mgte motor, could I drop the crank out of the bottom of the n/a motor, and just replace it with the turbo crank? are there any size differences?

I don't want to just do a motor swap because I don't have a wiring harness, or ecu or any of the turbo parts.

It sounds like you want to pull the crank witht he rods and pistons out of the bottom of the GTE block and put them into the GE block. Lots of issues with that:
- Pistons won't come out the bottom
- All the bearings are select fit, putting them in a different block will throw off tolerances. Mating it to different rods will do the same thing.
- Compression is different

Sadly you're not going to fix it cheaply

The clearances on the crankshaft are select fit. GE or GTE has nothing to do with it. And as long as it is apart, get pistons with more compression. 9.5:1 if you plan on adding boost later.

Waaaaat? Maybe on a stock vehicle running premium gas, otherwise I'll keep my safety margin, thanks.

 

[bioskyline]

whats wrong with the crank? just the nose is messed up??

 

[mk3-4-me]

how are your N/A pistons? why dont you use turbo crank and same pistons? just a thought...

 

[CT26smoker]

I have changed out cranks, without worrying about 'select fit' bearings.
If the engine has more than 75 thousand miles, they are no longer at 'ideal' clearances anyway.

Pull the engine, turn it up side down, pop the pan, pull the rod caps off, push the pistons down,
pull the main caps, and remove the old crank.

Then fit the good crank with new bearings that fit it (standards or oversize, both mains & rods)

No need to pull the head, unless you want (and can afford) a complete rebuild.

It will run another 75k miles (or until the stock rings give up the ghost).

If you want to build a turbo engine later, do it to a Late Turbo block, as they are stronger anyway (thicker main webs)

Not every rebuild has to be the Ultimate......
Some people just want to drive to work or school.

 

[89nasupra]

OP, there are ways to fix the problem you are having. I would not just throw another crank in there with out haveing it machined and all the bearings changed.

Yes some people just want to drive to work or school, but piece of mind is better knowing it will get you there and back with no ploblems because you spent the extra 200 bucks and did the job the right way.

 

[Poodles]

I have changed out cranks, without worrying about 'select fit' bearings.
If the engine has more than 75 thousand miles, they are no longer at 'ideal' clearances anyway.

Pull the engine, turn it up side down, pop the pan, pull the rod caps off, push the pistons down,
pull the main caps, and remove the old crank.

Then fit the good crank with new bearings that fit it (standards or oversize, both mains & rods)

No need to pull the head, unless you want (and can afford) a complete rebuild.

It will run another 75k miles (or until the stock rings give up the ghost).

If you want to build a turbo engine later, do it to a Late Turbo block, as they are stronger anyway (thicker main webs)

Not every rebuild has to be the Ultimate......
Some people just want to drive to work or school.

In this case, he's better off rigging the snout. If you're going to pull the engine and replace bearings and crank only to do it over again soon it's a waste of time/money.