Only thing that makes a motor a 6 bolt is the crank?

[Jeff@Slowboy]

I am sitting on a 7 bolt Jasper motor right now.
It is in mint condition, only like 10,000 miles on it.

If I gutted it down to just the bare block, and bought a 6 bolt rebuild kit, would that change the motor to a 6 bolt? Or is the 6 bolt an entirely different block from the 7 bolt?

Thanks in advance, sorry for the "newb" question

 

[Jeff@Slowboy]

Right, so if i bought a 6 bolt rebuild kit (crank rods pistons bearings rings etc) and put it into this block that used to eb a 7 bolt it would work then

Basically I just want to make sure that the actual block is the same, and its only the internals that are different between a 6/7 bolt

 

[Strm Trpr]

Ummm, you can not drop in a 6-bolt crank rods and pistons into a 7-bolt block and make a 6-bolt.
I'm pretty sure that's impossible, but correct me if I'm wrong.

 

[pepsi21463]

Both the blocks are different, so I wouldnt try it.

 

[1g_tsi_awd]

Yea, two different blocks...

7-bolts are not that bad... ONly 7-8% of them crankwalk, it is not as common as everyone thinks...

 

[pepsi21463]

Yea, two different blocks...

7-bolts are not that bad... ONly 7-8% of them crankwalk, it is not as common as everyone thinks...

Just to add to the crankwalk thing. I personally have a built 7 bolt motor. The guy who built it supposedly has a crankwalk fix too that has been pretty dependable. I'm not sure what it consists of besides shaving the bearings to allow more oil to drip when it gets hot. I'm not sure on the exact details but I could probably find out since he built my motor.

 

[JayRolla]

Yea just build your 7 bolt. Ive seen 6 bolts walk also

 

[Jeff@Slowboy]

Well my dilemma is going to be whether to build a 7 bolt using this block from jasper which is basically brand new with only like 10k miles on it, or selling it and buying a used 6 bolt and building that up.

I dont plan on having the car on the road anytime soon, I'm working on a gt35r/gt40r turbo kit etc so the motor is going to have to be pretty beefy. It's going to be a long process so I want to do it right, and only do it once.

Advise?

 

[1g_tsi_awd]

7-bolt.

 

[pepsi21463]

I have pretty much that same turbo, just with a GT30 turbine instead of the GT35. Both turbos have the GT40 compressor and flow the same air. On my 7bolt I have CP Pistons bored .020 over, Manley rods, arp rod bolts, cometic headgasket, arp headstuds, and hks 272/272 cams. The pistons and rods can take all the power the turbo can throw at it, so that makes me happy. And the cams really let the turbo come alive in the higher rpm ranges.

The GT3540r flows 65 lb/min, so just make sure whatever you build can withstand 650-700whp if you really want to max that thing out.

 

[JayRolla]

I myself would build the 7 bolt since you allready have it.

 

[Gamble97]

My machine shop told me that the 6bolt has bigger oil squirters compared to the 7 bolt. Also my mechanice has his version of a "fix" for crankwalk also. He drilled holes in the block to get more oil to squirt on the back of the thrust bearings. That's all I know, but I'm sure there is more to it than that.

 

[blackbyrd]

There's many people who have many different "fixes" for crankwalk.
My question is, does anyone care to elaborate what the differences in the block are?
From my little research on dsmtuners, the differences are that the 6bolt has wider journal bearings. And that in theory you could just get your block machined to fit it's journals..
I'm interested in this as well, I have a 1g7bolt i'm sitting on(w/ bad crank), as well as an old 6bolt crank and a bunch of random parts.

 

[Gamble97]

There's many people who have many different "fixes" for crankwalk.
My question is, does anyone care to elaborate what the differences in the block are?
From my little research on dsmtuners, the differences are that the 6bolt has wider journal bearings. And that in theory you could just get your block machined to fit it's journals..
I'm interested in this as well, I have a 1g7bolt i'm sitting on(w/ bad crank), as well as an old 6bolt crank and a bunch of random parts.

Why not bring it to a machine shop and see if they can do it. I guess someone can always email AMS or RRE or someone that builds motors too.

 

[blackbyrd]

Yeah I will once I'm ready to build it, just curious if anyone else has before..

 

[GVR4592]

Just to add to the crankwalk thing. I personally have a built 7 bolt motor. The guy who built it supposedly has a crankwalk fix too that has been pretty dependable. I'm not sure what it consists of besides shaving the bearings to allow more oil to drip when it gets hot. I'm not sure on the exact details but I could probably find out since he built my motor.

You're referring to Jack, and it's been pretty proven that his fix doesn't work.

 

[pepsi21463]

You're referring to Jack, and it's been pretty proven that his fix doesn't work.

Well he did it on my car, I didn't pay for it another shop did. 700 miles so far on the new build, we'll see how it holds up.

 

[Defiant]

http://members.shaw.ca/costall/1000Q/answers-terms.htm#Whatsa7boltenginev

What is a 6-bolt engine?
What is a 7-bolt engine?

A 6-bolt engine is one that has a 6-bolt flywheel - that is, there are 6 bolts holding the flywheel to the crankshaft. A 7-bolt motor has 7 bolts there.

"Along with the flywheel change, there are many other internal changes between the two engines. The crankshafts are different sizes, as are the rods and crankshaft seals. 6-bolt motors have 'big' rods, while 7-bolt engines have 'small' rods. The journal and bearing widths different, although the bearing diameters are the same.

There may also be other changes between the two engines, and the parts are not interchangeable. "

 

[JayRolla]

You're referring to Jack, and it's been pretty proven that his fix doesn't work.

If you guys are talking about Jack and his bro Kevin in Colorado Springs, then yes his fix does work. I never knew what he did. He said that he has had more 6 bolt strokers fail than his 7 bolts. But a 2.0L is better as a 6 bolt from what he has told me. The man is a DSM motor guru. He builds 2-3 strokers a week and 5 tranny rebuilds a week, im pretty sure he knows what he is doing. He is also a good friend of mine, he has been working on my car way before he even had a shop.

 

[GVR4592]

If you guys are talking about Jack and his bro Kevin in Colorado Springs, then yes his fix does work. I never knew what he did. He said that he has had more 6 bolt strokers fail than his 7 bolts. But a 2.0L is better as a 6 bolt from what he has told me. The man is a DSM motor guru. He builds 2-3 strokers a week and 5 tranny rebuilds a week, im pretty sure he knows what he is doing. He is also a good friend of mine, he has been working on my car way before he even had a shop.

According to a post on the Dsmlink forums, he did his fix on an engine, it walked within a few months. He rebuilt it, it walked again within 10 minutes. He pulled the engine from his car, installed it in the customers car, and walked that one as well. Now he's building the customer a 6 bolt.

So it's pretty safe to say that it doesn't work. I don't think there will ever be a real fix for crankwalk. There are a few tricks you can do to help prevent it, but it's still a risk.

However, he seems to have the best damn customer service I've ever heard of. I don't think there's any other shops that would fix it three times free of charge, even if it was there screwup.

 

[JayRolla]

According to a post on the Dsmlink forums, he did his fix on an engine, it walked within a few months. He rebuilt it, it walked again within 10 minutes. He pulled the engine from his car, installed it in the customers car, and walked that one as well. Now he's building the customer a 6 bolt.

So it's pretty safe to say that it doesn't work. I don't think there will ever be a real fix for crankwalk. There are a few tricks you can do to help prevent it, but it's still a risk.

However, he seems to have the best damn customer service I've ever heard of. I don't think there's any other shops that would fix it three times free of charge, even if it was there screwup.

Is this lately? Yes motors can walk and there is no real fix but he said it helped. We talked less than a month ago and he was telling me that he builds better 7 bolt strokers and likes to build 2.0's out of the 6 bolts, but he could have changed his ways since then. Last time I was there his bro just finished his 2.5L stroker or close too that. Has a holset turbo set up, man that car is so mean.

And yes his customer service is incredible. My brother got a used tranny from him that failed in about 2 months. He replaced it, then that one failed in like 5 months. He then replaced it again. He still has that tranny and all is well. Anyone that lives in CO should think about using this guy. They are great and know a lot about these cars. They can fix anything. Also has some of the best deals in town, charges $45 an for labor which is an awsome price.

 

[pepsi21463]

According to a post on the Dsmlink forums, he did his fix on an engine, it walked within a few months. He rebuilt it, it walked again within 10 minutes. He pulled the engine from his car, installed it in the customers car, and walked that one as well. Now he's building the customer a 6 bolt.

So it's pretty safe to say that it doesn't work. I don't think there will ever be a real fix for crankwalk. There are a few tricks you can do to help prevent it, but it's still a risk.

However, he seems to have the best damn customer service I've ever heard of. I don't think there's any other shops that would fix it three times free of charge, even if it was there screwup.

Yeah this was recently, theres a thread about it over at dsmtalk. He just finished building my motor because a shop sent it to him. They too had to pay for 2 of my motors because they screwed them up. And last I talked to Jack he was up to 4-5 motors a week.

Hopefully my 7bolt will hold up, the last 8 days its run consecutively is a record for the year

 

[JayRolla]

Yeah this was recently, theres a thread about it over at dsmtalk. He just finished building my motor because a shop sent it to him. They too had to pay for 2 of my motors because they screwed them up. And last I talked to Jack he was up to 4-5 motors a week.

Hopefully my 7bolt will hold up, the last 8 days its run consecutively is a record for the year

That shop would not be a guy named DON in denver is it. Ive heard of his work. Jack explained how he builds motors that walk all the time. If Jack builds it, it should last. Most of his motors never walk. He used to come over to my house and work on my car for free, just because it was fun. Now he does it so much he hates working on these cars. Hes a good guy though.