!!1st 7BOLT SWAP??

[MarsaGSX]

hey,
Iam in beginning of proces of build my engine..Iam thinking to make a 6Bolt Swap..So Iam searching for details on few forums and web..RRE,Magnus site..
Today found this forum..and have to say Iam very confused

thats the first post:

by lancerman
Just completed my first 7 bolt swap. Yeah you heard right. While most 7 bolt owners are busy swapping in 6 bolt block in their cars I did just the opposite. I installed a 7 bolt block (head and block) in what used to be a 6 bolt car. WHY???

bulletproof girdle. ties the main caps together to keep them from moving around.
lighter and likely stiffer crank. 5.5 pounds lighter than a 6 bolt crank.
windage tray. reduces the amount of oil the crank has to spin through.
stiffer bores. bores are thicker than 6 bolt bores. allows more reliable ring seal.
head. intake ports are better design. the large 1g ports were designed for cyclone intakes. coolant passages are better in 7 bolt heads.

readers digest version. 7 bolts are 1 better than 6

http://www.tamparacing.com/forums/mitsubishi-tech/347309-1st-7-bolt-swap-running.html

http://www.tamparacing.com/forums/mitsubishi-tech/347271-6-bolt-versus-7-bolt.html


Do I understand right purpose of Crankwalk is bad Oil system in block..bearings are little lubricated + bad Squirters???,or wrong bearings toleration??
THX

now tell me what to do..make 6Bolt Swap or stay with 7Bolt??..and still if stay with my7Bolt...how to check crankwalk??I can´t translate this part(bulletproof girdle. ties the main caps together to keep them from moving around)WTF



Venca

 

[MarsaGSX]

its OKAY to everyone????

Nobody is confused he swaped 7Bolt into 1G???

Venca

 

[drivemusicnow]

There are lots of reasons why the 7 bolt is a better motor than the 6 bolt. Most of the reasons you mentioned. They were the updated design, and thus had all the engineering extras added to them.

HOWEVER: 7bolts fail more often than 6 bolts. It just happens. They crankwalk, and while I agree that this issue is a bit overplayed, none the less it happens. No one wants to put money into a block that is going to possibly fail horrifically within a certain time period. You have to understand that NO-ONE truly understands why the crank walks, and while many have ideas and thoughts and theorys about it, they haven't proven to be effective consistantly.

Either motor works, most people prefer the 6 bolt because you don't see them failing as often or spectacularly as the 7 bolts.

 

[drivemusicnow]

bulletproof girdle. ties the main caps together to keep them from moving around.

He is talking about the girdle design, which is the seperate piece that is the bottom half of the main bolts. He is saying that because of it's design it doesn't allow the main caps to move around nearly as much as they could in the 6 bolt. I do not know if I agree with this fully, but it is possible.

 

[tstkl]

the most logical thing I have heard which causes crankwalk is the fact that the 7 bolt cranks were not nitrate covered from the factory, so they are more prone to rust. I don't know if its true, but it is what seems most logical.

playing devils advocate, It also appears that most cars that do crankwalk, crankwalk in their earlier miles, and most 7 bolts with 100k+ miles aren't likely to crank walk. If rust is what is causing them to fail, then the older ones would be more prone, but they are not.

crank walk is a very mysterious thing.

 

[drivemusicnow]

Its not rust. The only things that tend to make sense are:

Oil issues, something gets clogged, and crucial parts don't see enough oil. (backup for this opinion is that if you ever see a motor that has been oil starved, it has similar damage to a "crankwalked" motor. but logic says most motors wont have a clogged oil passageway in the first couple thousand miles.. who knows)

Thrust bearing design... I'm not sure how this would play into it, however some people have said that due to the smaller main bearings the thrust bearing does work well enough. I'm unsure.

 

[tstkl]

it wasn't rust, it was just the fact that it lacked this protective chemical layering which caused it to corrode or something and go out of balance or whatever.

then again, I've never seen the inside of a 7 bolt, so we'll just have to leave this up to people who know what they are talking about. aka not me,

 

[wishihadatalon]

if you are worried about the main caps moving how about getting a kiggly racing main girdle. http://www.kigglyracing.com/Main_Girdle.htm
Yes the ports are better on a 2g head which is why I will be swapping to one on my 6bolt block. You have to drill out the head bolt holes 1mm larger because 7bolt = 11mm and 6bolt = 12mm.
You can get a lightened crank if you are worried about it. Many vendors sell them. To me the risk of buying a motor from someone who had a "fix" for crank walk doesn't seem worth it when everything you mentioned can be fixed on a 6bolt.

 

[MarsaGSX]

hey,
well..if NO ONE really KNOW the purpose of Crank walk..will stay with well-tried way..6Bolt swap..
I can buy 90´1G eclipse awd..car is parted out..eng+tranny is outta car..interior too..So will use this 6Bolt block to swap into my 2G..and sometimes in future will build this 1G just for race/fun.. will pay 870-900usd with registration book...

BTW ..when I first come into DSM world..and first time read that 1G engines are installing in 2G cars..was really confused..cus 2G engine is newer..mean engineers has to make some changes ..to better..used better materials,better parts..turbo..blah blah..its like Evolution..BUT in this case..mean 1G vs2G..its worst I think...turbo ..1G Rules..
bigger Throttle...,bottom end, and 2G got "better" only ex. mains..and maybe eng. Head..
and those are only thinks I know..
They should make NEXT LEVEL when building next generation/..model/...vesrion...not worst than previous type..
Venca

 

[LRS95TSI]

the 7 bolts were probably redesigned to be more cost effective...they figured that the motor would still support a turbo'd vehicle without issues...however the IM, the head, turbo, and rods are not as good as a 6 bolt...yes the 2g head can be PROFESSIONALLY ported to outflow a 1g, but why not just get a good stage X 6 bolt head and do it all, then you have the intake mani and tb all as a whole...the 14b is def better then the t-25 and the rods look like tooth picks compared to 6 bolt rods....

those are my interpretations, but i'm no expert either...

build a 6 bolt motor and swap the whole thing over...most 6 bolt stock parts can handle the majority of what you throw at it.

 

[wishihadatalon]

the 7 bolts were probably redesigned to be more cost effective...they figured that the motor would still support a turbo'd vehicle without issues...however the IM, the head, turbo, and rods are not as good as a 6 bolt...yes the 2g head can be PROFESSIONALLY ported to outflow a 1g, but why not just get a good stage X 6 bolt head and do it all, then you have the intake mani and tb all as a whole...the 14b is def better then the t-25 and the rods look like tooth picks compared to 6 bolt rods....

those are my interpretations, but i'm no expert either...

build a 6 bolt motor and swap the whole thing over...most 6 bolt stock parts can handle the majority of what you throw at it.

You mis read. The runners on a 2g head is stock form are better. Higher runners = for straighter shot at the cylinder and increased velocity. Where as a 1g head will pretty much make a 90* bend before entering the cylinder. But yes a 1g intake manifold and cams are better. Btw bigger is not always better

 

[tstkl]

how can you say the 1g intake manifold is better than the 2g intake manifold, yet the 1g head is worse than the 2g head. There is no way to test, since using a 2g intake manifold on a 1g head will make less power than a 1g intake manifold on a 1g head, and a 1g intake manifold on a 2g head will make less power than a 2g intake manifold on a 2g head. Since the two do not have the same port sizes, theres no way to do a side by side test of the intake manifold. Flow bench numbers are really all we have.

 

[gsxtacy]

I know the culprit behind 7 bolt crankwalk.

It is the CRANKSHAFT.

It has ALWAYS been the crankshaft.

The 92-99 7 bolt design IS SUPERIOR to ANY 6 bolt EXCEPT FOR THE LACK OF HARDNESS ON THE CRANKSHAFT.

I do not have a 7 bolt crankshaft and a scrap 6 bolt crank to CUT IN HALF, but if I did I am sure it would look like

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and you add in the thought of a Oil cooler that is coupled to the hot coolant FROM the block, you start to understand why 2G owners manuals recommend 20W-50 oil for most climates. The thicker oil carries the heat away better and does not break down as fast as 5w-30.

Drive the car on the verge of overheating one time, and the crank can get the brunt of the effects.

I have always wanted to build a Race Spec 7 bolt, but I do not know how hard it would be to get the crankshaft hardened more....I bet it could be done though

Anyone want to donate a 7 bolt....I'll build it and let you all know?

 

[GVR4592]

If the hardness of the crankshaft is the problem then why is it the bearing wears excessively before the crankshaft does? The nitrating doesn't penetrate .045" on a 6 bolt crank it's more like .008"

Also if the 7 bolt is so superior than why are there NO 7 bolt engines and/or heads making big power?

 

[gsxtacy]

If its not the crank, then WHY can you turn a 6 bolt crank up to .020 if you wipe a bearing, but on a 7 bolt you can throw the crank in the TRASH? I attempted to have a 7 bolt crank turned once, and at .010" the machine shop called and said the crank is junk, it has soft metal in the middle.....

I do not know any further or care at this point...the metal composition in the 7 bolt cranks SUCK....