6bolt 7bolt main cap swap?

[ilikerice]

i have a problem with my 4g63 motors:

back story, i got this gsx with 2 motors and bare block with alot of extra parts.

-the 7bolt i was taking apart ended up having a broken rod and busted a hole in the block and destroyed the main cap girdle and crankshaft. (first picture)

-so i moved on to the 6bolt and was about to put it on the engine stand when i noticed im missing the trans bolt ear lobe. so this block is toast also, but i continued to take it apart on the ground. i found that the crank is still in good shape and so are the main caps. (second picture)

-the bare block i received looks like it has potential, but i dont know if its a 6bolt or a 7bolt. is there a way to tell just by looking at a bare block? (third picture)

Now to the question. i would like to swap the crank and main caps from the 6 bolt to the unknown block. would this be possible if i take it to a machine shop and have the line bore, hone, etc. everything and do all the special treatments for resurfacing and cleaning this bare block up?

please, any and all input is greatly appreciated.

 

[jimbob_843]

I would use the bottom block and just find a main girdle. 6 bolt caps wont work because a 6 bolt crankshaft is a different size then 7 bolt. Or atleast i think it is, someone back me up here . Either way i would recommend not using a busted block and since your getting a shop line everything get arps.

 

[94_TSi]

6 bolt blocks are main caps 7 bolts are a girdle.

 

[ilikerice]

ok, so your saying the third picture is a 7bolt? that is my main question. i have 6bolt caps and crankshaft, i just dont have a 7bolt girdle or crankshaft ### it got destroyed. i am hoping the third pic is a 6 bolt.

if the bare block (third pic) is a7bolt block. will any year 90-99 7bolt crank and girdle be ok to use as long as i line hone them with the block?

this is my first Mitsubishi ever.. so im still trying to figure out compatibilities between engines and years.

 

[19Eclipse90]

The first one would be a 1G block; without oil squirters and it being a 7-bolt, it is almost absolutely certain.

Honestly, the second block doesn't appear to have oil squirters -- not that it matters a great deal with what you want to do since a 6-bolt crank is a 6-bolt crank, just pointing out the fact -- are you sure it's a turbo block?

The third block is a 2G (thus, 7-bolt) block based on the oil squirters. Yes, any 92.5-99 7-bolt crank will work. I would imagine that all 7-bolt girdles are similar enough to be interchangeable so long as you get it and the block correctly machined/line honed.

On to mixing and matching main 6-bolt and 7-bolt internals, I really can't give solid advice. All I can give is my opinion which is that I wouldn't mess with it.

 

[ilikerice]

i am pretty sure the 6bolt is a turbo block. im only going by my visual conclusions.
1-I had to take an oem turbo manifold off the block
2-Looking at the rods on the 6bolt compared to the 7bolt (1st pic), the 6bolt had beefier rods.

Thank you 19eclipse90. that information is very helpful. this will definitely help me on my choices on my next step on this project..

if anyone has any 4g63 blocks, or 7bolt girdles they are willing to part with, please pm me. i will be looking for this. Also probably will accept a short block preferably a 6bolt, but can no longer be picky.

thanks for the help guys.. greatly appreciated. Also, more input and suggestions is welcome on this thread. i will be reading it.

 

[19Eclipse90]

i am pretty sure the 6bolt is a turbo block. im only going by my visual conclusions.
1-I had to take an oem turbo manifold off the block
2-Looking at the rods on the 6bolt compared to the 7bolt (1st pic), the 6bolt had beefier rods.

Any manifold could have been swapped onto the block. Manifolds, valve covers, oil filter housings, oil pans, thermostat housings, etc. are no way to judge what the block really is.

Similarly, all 6-bolt rods are beefier than 7-bolt rods. There is no difference between a 6-bolt turbo and 6-bolt non-turbo rod.

I can't see the oil squirters from my end (the guys lining the bottom of each of the cylinders below). That tells me it isn't a turbo block. You can check the VIN by following this post: http://www.dsmtuners.com/forums/newbie-forum/397262-2-0-turbo-non-turbo-motor.html#post152521150.

You must be logged in to view this image or video.

 

[ilikerice]

awesome.. thanks, i confirmed it is NOT a turbo 6bolt..

next question:
i found a 7bolt on craigslist and he says its a 2g turbo 7bolt. crank, girdle, rods. claims its all in good shape with 100k miles on the block.. ofcourse i will machine it and replace everything with a new full gasket rebuild kit.. he said make an offer.. is 100 dollars low balling it? or should i wait for another deal?

 

[19Eclipse90]

Although it is a perfectly valid offer considering he didn't list a price, if it were my shortblock, I might be slightly offended on receiving that offer.

I'd expect to pay between $250 and $400 for a good condition shortblock. On the other hand, the worst the seller can do is say no (perhaps by using other choice words) and maybe you'd be able to bargain with him afterward.

 

[dsmornothing]

The early 7 bolts are different than late 7 bolts (97-99) and the main girdles are different. If it is an early block I do have a couple main girdles, Id be willing to part with one of them. I will take pictures of my early block vs my 99 7 bolt if you would like.

 

[donniekak]

Fitting a girdle/main caps from another block will run about $200 in machining costs.

 

[19Eclipse90]

The early 7 bolts are different than late 7 bolts (97-99) and the main girdles are different. If it is an early block I do have a couple main girdles, Id be willing to part with one of them. I will take pictures of my early block vs my 99 7 bolt if you would like.

I'd like to see this. Please post up when you get chance.

 

[ilikerice]

"dsmornothing" I'd really like to see those also so i can compare. If it is a match, I would like to possibly take one off your hands for a fair price.

I just talked to the guy and I didnt offer $100. I asked what he was asking.. Surprised, he asked $175 for block, crank, rods and pistons.. I think ill take that offer this weekend.. I am, however, still interested in that 2g girdle if it fits.. Would be nice to have another motor to work on while i beat the crap out of this one IF i ever get it running.

 

[red1993gsallmt]

i was always told not to use caps from different motors

 

[19Eclipse90]

You shouldn't if you can avoid it (and in most cases you can) or aren't upgrading (i.e. billet mains).

As donniekak pointed out above (and in multiple other threads also), the required machine work for doing so is not cheap nor is it common work. For that price, you could find a bare block with the matching main caps/girdle or, as ilikerice has, find a complete shortblock for less than that amount.

 

[ilikerice]

Ok, I got the new block sunday and just droped it off at the machine shop yesterday to have it examined, measured, heat sinked, etc.. the basics.. then he will let me know my options from there.

Using work computer so cant upload pictures, home internet is down til thurs.

I'll get a build thread going here soon. Tried starting a journal but for some reason i couldnt get my pictures to upload.

Thanks for all the help sofar.

 

[BeatupVR4]

Why has no one just looked to see if there are bolt holes for motor mounts in the "unknown" block?

 

[ilikerice]

First time i heard of this observation for block identification. I'm gonna check this out tomorrow.

 

[19Eclipse90]

I didn't think there was a point mentioning anything about the mounting holes considering the block was identifiable by its oil squirters. But Cutlassjim is correct -- if it is a 2G block, it won't have bolt holes in the front of the block for an engine mount.

How else could you identify it as a 2G block?
-VIN: http://www.dsmtuners.com/forums/cylinder-head-short-block/390960-block-identification.html#post152446420 and use this to find out the year of the block
-Block Coolant Line (also shows lack of motor mount bracket holes): http://www.dsmtuners.com/forums/newbie-forum/385767-2g-block-coolant-line.html
-Transmission-to-Block Mounting Holes: http://www.dsmtuners.com/forums/newbie-forum/383946-my-first-dsm-motor.html#post152352853