1gb 7bolt vs 2g 7 bolt engine

[spook302]

What is the differenece? I know the 1gb engine had the same comp ratio as the 6 bolt. Do the 1gb use the 1ga top end or the 2g top end? Did the 1gb have a crank sensor(I dont think so but i am asking anyways)? What are the differneces between 1gb 7 and 2g 7?

I am asking because I have been looking for a sheel for my 1ga and body parts to start a 2g project I have. A customer of mine came in and said he has a clean 1g shell and a clean 1gb shell. I have a built head for a 2g 7bolt. will that work on the 1gb 7 bolt? Or am I wasting time. point is I dont like the 2g style as much as the 1g. i was going to build the 2g gst for a daily and have my 1ga as my toy. i would rather have the 1gb as the daily seeing as its awd and I live in CO plus its clean and the 2g needs a front clip and a shortblock plus paint and other things to run. The 1gb i could by has a bad head on it. plus its complete and doesnt need paint.

 

[19Eclipse90]

Much of the block is the same, one of the main difference is a 1G to 2G difference in the casting. A 1G -- both 6-bolt and 7-bolt -- block (top) lacks one of the transmission mounting points found on a 2G (bottom), shown here:

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Another difference is the type of oil squirters used and how they are installed in the block. The 1G cars all used a squirter type that bolts into an oil galley while the 2G uses a jet that is pressed into the area of the main bearings. This difference can be seen here: Magnus Motorsports » Crankwalk Theory.

While the 2G uses a crank sensor, it uses the same front casing/oil pump as a 1G 7-bolt, so a 1G 7-bolt block could be set up to use a crank sensor, no problem. But no, a 1G 7-bolt does not use a dedicated crank sensor.

The 1G 7-bolt uses a head with 1G style (large) intake runners, but uses the same (smaller than 6-bolt) head bolts as a 2G, so any 7-bolt head bolts right up. You can use a 2G head on a 1G 7-bolt block. It would also be wise to use a 2G intake manifold with a 2G head.

Hope that helps you out.

 

[spook302]

It does help. That's what I needed to know. I know ill be Down grading the original set up by installing the 2g head and intake but its going to be the daily. And I can deal with it.

 

[19Eclipse90]

On the contrary, a 2G head and intake combination in a 1G is considered an upgrade. Although it has smaller runners and intake ports, the design of the 2G intake and 2G head provides better velocity and sharper delivery into the cylinder for more efficient combustion.

 

[spook302]

really? Well that sounds good. Ill be porting out the 2g manifold to allow the 1g tb to work properly as well.

 

[sypherzero]

Sorry to bring this back up, but where the 1g 7 bolt is missing the extra hole for the trans, what do you do about that? Is it okay to leave it unbolted, or what? Thanks!

 

[19Eclipse90]

You leave it be and forget about it.

Folks have been running 2G transmissions on 1G engines (like in the 6-bolt swap) for years. It's never been an issue.

 

[sypherzero]

You leave it be and forget about it.

Folks have been running 2G transmissions on 1G engines (like in the 6-bolt swap) for years. It's never been an issue.

Alrighty, thank you sir!

One other question though. I just got a 1g 7 bolt block, and am wondering if I could use the crank, pistons, and main girdle from my 2g 7 bolt? Thanks again!

 

[19Eclipse90]

The crank and rods are the same and there is no reason why you can't use the 2G pistons in the 1G block.

As for swapping the girdles, don't unless you have the proper machine work done. http://www.dsmtuners.com/forums/152564542-post11.html

 

[rebuild4g63]

Much of the block is the same, one of the main difference is a 1G to 2G difference in the casting. A 1G block (top) lacks one of the transmission mounting points found on a 2G (bottom), shown here:

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

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

Another difference is the type of oil squirters used and how they are installed in the block. The 1G cars all used a squirter type that bolts into an oil galley while the 2G uses a jet that is pressed into the area of the main bearings. This difference can be seen here: Magnus Motorsports » Crankwalk Theory.

While the 2G uses a crank sensor, it uses the same front casing/oil pump as a 1G 7-bolt, so a 1G 7-bolt block could be set up to use a crank sensor, no problem. But no, a 1G 7-bolt does not use a crank sensor.

The 1G 7-bolt uses a head with 1G style (large) intake runners, but uses the same (smaller than 6-bolt) head bolts as a 2G, so any 7-bolt head bolts right up. You can use a 2G head on a 1G, but you'll still use the 1G cam sensor and the 1G thermostat housing. I'd recommend using the 1G intake cam as well just because I'm not positive if the 2G cam has a slit for the 1G CAS. It would also be wise to use a 2G intake manifold with a 2G head.

Hope that helps you out.

OK so my rear main seal looks like the bottom pic, but my water pump does not fit!!!!! I even took my water pump to checker auto to cross reference and it matched up. I have a feeling I have a 1g 7 bolt. Irritated as hell. I have spent 1300 plus on anothers word. I purchased all my parts from extremepsi besides the block. and the extreme psi gaskets don't fit everything. supposed to be a 97 gst 2g 7 bolt block.

 

[bryanwheat]

The water pumps are different between the 2 engines.

 

[19Eclipse90]

I think you're making this too difficult.

Focus on the block itself and the encircled holes. The web of material off to the right with a fourth circled bolt hole in the bottom picture compared to the lack of material without a fourth circled in particular. That is the distinction between a 1G and 2G block.

 

[rebuild4g63]

OK so my rear main seal looks like the bottom pic, but my water pump does not fit!!!!! I even took my water pump to checker auto to cross reference and it matched up. I have a feeling I have a 1g 7 bolt. Irritated as hell. I have spent 1300 plus on anothers word. I purchased all my parts from extremepsi besides the block. and the extreme psi gaskets don't fit everything. supposed to be a 97 gst 2g 7 bolt block.

I looked at the crankwalk theaory and It is helping Im saying I think I have a 1g 7bolt. My main journals match the 1g, and a lot of things match the 2g. I must have the crossover engine from around 92-93. Plus my water pump I believe is a 1g size. It is larger then the 2g. The mounting area for the tranny matches the 2g and the rear main seal as well. I ended up with the funky engine here is a link to a pic of it. http://www.dsmtuners.com/forums/newbie-forum/429670-ecu-problem-what-help-2.html Thanks for the help! much needed

 

[bryanwheat]

I looked at the crankwalk theaory and It is helping Im saying I think I have a 1g 7bolt. My main journals match the 1g, and a lot of things match the 2g. I must have the crossover engine from around 92-93. Plus my water pump I believe is a 1g size. It is larger then the 2g. The mounting area for the tranny matches the 2g and the rear main seal as well. I ended up with the funky engine here is a link to a pic of it. http://www.dsmtuners.com/forums/newbie-forum/429670-ecu-problem-what-help-2.html Thanks for the help! much needed

If it has the extra mount spot for the bellhousing than it is a 95+ block. There was no hybrid block.

 

[rebuild4g63]

There is google it. It was made when they switched to 7 bolt. Here is a link to say it does exsist! Welcome to Slowboy Racing
If you had what I have you would be pissed

 

[pauleyman]

I see nothing that suggests a hybrid anything. 90-92 are six bolt. 93-94 are 7 bolt and share much of the same external architecture as 90-92. 95 up are also 7 bolt but the external architecture is different. No provisions for motor mounts on the block, differerent/extra tranny bolts and different water pump configuration as well as different size ports on the cylinder head.

 

[19Eclipse90]

No one here has told you there is no such thing as a 1G 7-bolt block which is what you linked to. That's why this thread exists in the first place.

We know it is a 7-bolt block. What we are trying to determine is if it is a 1G 7-bolt block or a 2G 7-bolt block so you can get the right parts, like a water pump. So far, what you have told us, specifically that it matches the 2G on the transmission side, points to you having a 2G 7-bolt block.

 

[pauleyman]

And there are three different type of squirters. 90-92 are bolt in. 93-94 are press in and 95 up are also press in but different style than 1g. Oiling architecture is different on 2g also. Much debate about this.

 

[rebuild4g63]

here is another link . 1gb 7 bolt block [Archive] - DSM Forums: Mitsubishi Eclipse, Plymouth Laser, and Eagle Talon Forum: DSMtalk.com

 

[bryanwheat]

And there are three different type of squirters. 90-92 are bolt in. 93-94 are press in and 95 up are also press in but different style than 1g. Oiling architecture is different on 2g also. Much debate about this.

93-94 are bolt in just like the 6 bolt.

 

[rebuild4g63]

I have seen the pictures and where to look to figure out what is what, and I have a mix of both. I would post pics on here but im out of room. I wish I just bought a crapped out engine and started from there for sure. I am a beginner and know I have aaaa lloooottt to learn. but I am convinced it is a 1g 7 bolt. Not what I wanted for sure.

 

[bryanwheat]

Well if it has the 2g extra bolt on the bellhousing it is a 2g block, no question about it. They didn't use that block in any 1g cars. There are no mount holes on the front of the block for the roll stop.

 

[pauleyman]

The two block pictures also show one with the main seal housing and the other doesn't. You either have one tranny bolt style or the other. That's it. So....do you have the bolt pattern of the top or bottom picture? If it's the top its a 1g motor. If it's the bottom its a 2g motor. It's just that simple.

The first three or four posts in that link are flat wrong.

 

[rebuild4g63]

The two block pictures also show one with the main seal housing and the other doesn't. You either have one tranny bolt style or the other. That's it. So....do you have the bolt pattern of the top or bottom picture? If it's the top its a 1g motor. If it's the bottom its a 2g motor. It's just that simple.

The first three or four posts in that link are flat wrong.

First of all this is a fun thread . I just posted those links to show there is a 1g 7 bolt. I have read about this block before. It is almost like trying to figure out if a god is myth or reality hahah. If you read everything I have posted you must know I have a strange block. It is a 7 bolt for sure no questions asked!!! It also has 1g genetics as well . I think i'm going to start a new thread to look deeper into this subject It isn't worth it but the arguments are awesome. I will call the dealer tomorrow and check the serial # . I tried calling yesterday but they were closed. How can I post more pictures on here? Do I need to delete the ones I already put? Kinda doesn't make sense.

 

[bryanwheat]

Well there is no 1g 7 bolt that has the 2g bellhousing extra bolt hole. Get that out of your head. It doesn't exist. There is a 1g 7 bolt, and a 2g 7 bolt. As i said, take a pic of the bellhousing side of the block and the front. I will tell you exactly what it is. Make a photobucket account, upload the pics on that site than post the image location on here. The reason that your rear main seal retainer looks like the 2g 7 bolt more than the top picture is because the top picture is a 6 bolt engine. A 1g 7 bolt will have the same rear seal retainer as the 2g 7 bolt.