Stressed out with engine

[Stapl3]

You misread.

 

[gyuen]

Thanks for all the info guys. I was planning to switch to an Exedy or Clutch Masters twin plate clutch anyways to save on the thrust bearings. Believe they are only 2100lb pressure plates or less. I am also planning to cryo every engine part I have. Anyone heard of cryo on the bearings? Also, has anyone every put a 7 bolt crank in a 6 bolt block? I noticed my Eagle rods required 6 bolt bearings.

 

[arash15]

stick with the 7 bolt dont bother selling exerything you already have. the 7 bolt is just as good as the 6 bolt, crankwalk is highly overrated.

 

[gixrman]

did you try kar-king? he has some good deals.
Any motor can crankwalk (even 6 bolts)and with the amount of stress that is inflicted on a turbo lowerend things happen. I have 105k on mine and disconnected the clutch switch(60k) and run mobil1 and have good oil pressure.

 

[Enraged78]

Yes it does make very much sense.

one question though. Why does the thrust bearing wear and not the block if it is weaker? or when the girdle is torqued down does it misalign the rest of the motor?
i had almost 3mm of endplay when i pulled my 7 bolt

gyuen. I rebuilt my 7 bolt only to have it walk in 10,000 miles don't risk it.
I wish i was smart enough to have just done the fully built 6 bolt swap the first time and save myself 2,000 bucks. i was nervous about all the conversion stuff but its not hard at all. But live and learn.

JJ

Thanks, I appreciate the thumb.

My theory on that is that the weaker metal flexes more when everthing is torqued down. Not just the head, but when you torque the girdle down, it also induces some flex into the block. I believe that this flex is enough to throw the thrust bearing out of alignment, and cause it to wear prematurely. I also belive that the earlier blocks, made of stronger material, are not as prone to this flexing as the later blocks. It may be also be why mitsu later moved to a two-piece bearing. A two piece bearing may shift a little more, but would be under less stress as the block flexes.

I just finished my early '95 7-bolt, and it will be in the car soon. I'll post my results. I can tell you that the clearances after the motor was assembled were amazing. Crank rotation was super clean, as well.

Matt.

 

[Enraged78]

It was my understanding that 2g turbo blocks do not have oil squirters. We disassembled my friends crankwalked motor, and I couldn't find the squirters to save my life.

You hit on some good points with using the 7bolt block that I didn't even touch on. CAS, waterpipe, etc. Kinda makes me hate the 6 bolt hype.

The squirters are in a wierd place. They look NOTHING like the 1G squirters. Looking down at the motor, you can see the problematic squirters arranged to the side of the block, just above the crank. Look right near the bearings, and they will be there.

Matt.

 

[Enraged78]

It's my understanding that most all 95's shared the same block as the 1G 7 bolt. Am I correct, or did I just misread somewhere?

Nope. The VERY early 2G's had a similar version of the 1G seven bolt, but it's not the same. There are a few key differences, like the turbo feed water passage on the front of the block.

As far as non-block specifics, the 1G oil pickup is also different. There are also lots of little differences, like the turbo, exhaust manifold, intake manifold, throttle body, head, oil feed location, pistons, rods, coil pack, resistor pack. The list goes on and on.

Matt.

 

[Enraged78]

Thanks for all the info guys. I was planning to switch to an Exedy or Clutch Masters twin plate clutch anyways to save on the thrust bearings. Believe they are only 2100lb pressure plates or less. I am also planning to cryo every engine part I have. Anyone heard of cryo on the bearings? Also, has anyone every put a 7 bolt crank in a 6 bolt block? I noticed my Eagle rods required 6 bolt bearings.

Eagle rods require 6 bolt bearings because the 6-bolt bearings have more surface area, and larger oiling holes. I know this because I had a seven bolt set sent to me and found the sticker on the inside of the Eagle box afterwards. When I got the six bolt bearings in, we compared the two. The difference was night and day.

Also, I'm testing out a new clutch from SPEC that just looks amazing. It's a seven puck-disk hybrid (7-puck on one side, sprung disk on the other), and holds up to 510 FT/LBs of torque. Stock pedal pressure, and only 2160 pounds of clamping force. It should be pretty sick. I'll post the model number later. I had an ACT, but my machinist recommended I return it after spending four hours with both ACT and SPEC in regards to the whole crankwalk problem. He was convinced that the SPEC clutch would do better. We'll see.

Matt.

 

[!^3]

The 6 bolt motor lacks the girdle a 7 bolt motor does. Aside from that, they don't have oil squirters, which lots of people plug for higher oil pressure.

In stock form 6 bolts are best in strength. When you're building a motor, that doesn't matter. The 1g 7bolt block design is just better to work with when building a motor IMO.

It seems the lack of this girdle has not stopped anyone from making over 1000hp with a 6-bolt setup. I have yet to see this with a 7-bolt.

I keep seeing you post about these 1g 7-bolt motors and I keep asking why they are better than the 2g 7-bolt motors (although they are the exact same block design, etc....the only thing different is the head on the 1g 7-bolt is the same as the 6-bolt) but I never get a response from you.

If you think you want to keep spouting off this information which is quite contrary to most applications these days, please show us the 1000hp 1g 7-bolt blocks. If you are simply bench racing the 7-bolt/6-bolt motors based on this girdle, please stop advising for it!

 

[sonicnofadz]

It seems the lack of this girdle has not stopped anyone from making over 1000hp with a 6-bolt setup. I have yet to see this with a 7-bolt.

I keep seeing you post about these 1g 7-bolt motors and I keep asking why they are better than the 2g 7-bolt motors (although they are the exact same block design, etc....the only thing different is the head on the 1g 7-bolt is the same as the 6-bolt) but I never get a response from you.

If you think you want to keep spouting off this information which is quite contrary to most applications these days, please show us the 1000hp 1g 7-bolt blocks. If you are simply bench racing the 7-bolt/6-bolt motors based on this girdle, please stop advising for it!

The truth is, 7 bolt blocks crankwalk, but alot times the people who have one refuse to believe it. If you run stock like power, or near stock power, yeah sure your block might last a long time without crankwalk. But what I've heard AND seen with my own eyes at my machinist's shop, high power 7 bolt blocks will NOT last. There are tons of theories out there about why the 7 bolt block is inferior (and YES it is statistically inferior, when you compare the number of failures to that of a 6 bolt design), but nobody knows for sure. The only thing we can do is OBSERVE what is happening. Why are there way more cases of crankwalk for 7 bolts? I'm not sure (and neither is anyone else), but I am damn sure that I will never waste my time building one. Show me a 7 bolt block that makes 800 hp+ and lives on pass after pass and then maybe you'll have some proof that the 7 bolt is actually a stable platform. You won't find one.

 

[98spyderboost]

There are tons of theories out there about why the 7 bolt block is inferior (and YES it is statistically inferior, when you compare the number of failures to that of a 6 bolt design), but nobody knows for sure.

Of course, how many 7 bolts exist compared to 6 bolts? I'm willing to wager the ratio is similar to the failure ratio.

 

[4GSixty3]

I love how someone starts a topic and it becomes the controversial issue of the year. Fact is, you can make some power with the 7 bolt block but eventually your gonna f#@! your bottom end. IMO and ALOT more fellow DSM'ers, go with a 6 bolt and avoid paying for it later. Your motor is already out so go about doing things the right way the first time .

Rick

 

[98spyderboost]

For some reason I'm reminded of a SMC forum conversation about 2 bolt vs 4 bolt.

 

[98spydert]

I keep seeing you post about these 1g 7-bolt motors and I keep asking why they are better than the 2g 7-bolt motors (although they are the exact same block design, etc....the only thing different is the head on the 1g 7-bolt is the same as the 6-bolt) but I never get a response from you.

How could you miss your prescious answer? It's like 3 posts before yours. The metal alloy is different and a lot weaker. Most newly rebuilt 7 bolts walk because they're not assembled correctly. Not the basic proper assembly but an assembly that takes into account for the flex that the block goes through compaired to the 6 bolt. For example, like someone else mentioned, when the mains are TQed down or the head bolts (especially the ARP stuff since you generally use more TQ than the factory gear) the block is tweaked a little becaue of the week material, throwing off clearences and leading to the thrust bearing failing. Using a TQ plate while assembling and taking religious clearence measurements is the only way to go. Many people have had great success with 7 bolt blocks while taking this approach, it's just too bad so many people with NO knowlege of the issue add to the stupid assumption that EVERY 7 bolt will walk some time, and especially when rebuilt or making big power. Gotta love DSMRumors.com

As for big powered 7 bolts, a simple search will show you some results you probably don't want to see. I don't really care about the subject(argument) so I'm not going to bother finding them.

 

[98spydert]

Thanks, I appreciate the thumb.

It may be also be why mitsu later moved to a two-piece bearing. A two piece bearing may shift a little more, but would be under less stress as the block flexes.


Matt.

The really sad thing is that the move to the two piece bearing makes it look like Mitsu knew the reason for crankwalk even though they claim not to and never had any intention of fixing the "mysterious" problem.

 

[98spydert]

Another thing, why isn't anyone recommending the Galant 4G64 block for this guy? If you're going to ditch the 7 bolt rebuild, get a different block, and get new pistons and rods, screw the 6 bolt in a 2G, go for the 2.4L. EVERYTHING from your 2G will bolt onto the block, even down to the oil pan. Use the galant timing belt kit, bolt on your 2G head, and slap the thing into the car.

 

[4GSixty3]

Bad, bad news... someone just posted this on talk.

Quote:
my crank is walking

so much for the 7 bolt 2.4s not crankwalking looks like 6 more months of downtime for me

Just found that on a search dealing with the 4g64. Now I have heard you can have a 6 bolt stroker motor but I'm not sure. But if you can't, right there is proof that a stroker motor has it's downsides also. Once again, save yourself the trouble and get a 6 bolt .

Rick

 

[Stapl3]

The 4g64 walking is about as common as a 6bolt.

 

[green92gsx]

The 4g64 comes in 6 bolt and 7 bolt form. It's hard to find the earlyer 6 bolts. Almost rare..

Bad, bad news... someone just posted this on talk.

Couldn't been just posted. Dsmtalk has been down for a month now. The real bad news is I think we won't see it again. It's just been too long now for a little repair.... God let us hope not.

 

[98spydert]

so much for the 7 bolt 2.4s not crankwalking looks like 6 more months of downtime for me

Every motor in existance has walked at one time or another(exageration ), it's not just a DSM thing. 2G 7 bolts just have more often unfortunatly.

It'd be nice to know how often it happens compaired to the 2G 63s though... If only there were some real world numbers we could look at and not just make assumptions off of half a dozen people's experiance.

 

[Stapl3]

The 4g64 comes in 6 bolt and 7 bolt form. It's hard to find the earlyer 6 bolts. Almost rare..

Supposedly there is an issue with the 4g64 6 bolt bolk bolting up to a dsm trans. Hopefully someone knows what I'm thinking of...

Every motor in existance has walked at one time or another

Rotary.

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[98spydert]

Rotary.

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, I've got a leash, I'll take it for a walk

 

[Turbo 2g awd]

It all depends what you want to do with your car. If you want to hit high HP levels then you might want to price out a 6 Bolt while your motor is apart. My 97 Talon walked bone stock stock at 33,000 miles. Mitsu put a brand new short block in and it walked again 40,000 miles later. This time I dropped in a SBR 6 bolt and I couldn't be happier. No crank walk and lots of power. But then again I have 4 local buddies with 7 Bolts and they have never had a problem.

 

[green92gsx]

Supposedly there is an issue with the 4g64 6 bolt bolk bolting up to a dsm trans. Hopefully someone knows what I'm thinking of...

I dunno where you heard that from? We had a 6 bolt 4g64 in are possession at one time. It has the same bellhousing bolt patteren as a 4g63. Same with the 7 bolt 4g64.

 

[sonicnofadz]

This is getting way too controversial. There is no need to wage the age old 7bolt vs 6bolt war here. The stronger and more reliable design has been found, and has been PROVED time and time again on race tracks all over the world. The whole 7bolt being made of a weaker alloy is total conjecture, although it is one of the most convincing theories I've heard about in quite some time! Does anyone know if there is actual proof (as in lab results) between the different cast iron strengths of the 7bolt vs 6bolt? I've never heard of anyone ever claiming this before (I might just be ignorant).