Building a 7 bolt... What clutch?

[EclipseGST]

Well I picked up a 7 bolt motor from a buddy, Eagle rods and Ross pistons. Just going to build it for fun and see what can happen before the end of the year. So I been told by a member here that I need a Twin disk no matter what. Personally I think the DXD clutch I have now will be just fine, maybe get the 6 puck clutch from Southbend to hold more power, but running a twin disk is going overboard in my opinion.

Also this person thinks that all and every 7 bolt that makes power will crank walk no matter what. So if its going to get CW no matter what then why should I get a twin disk to slow the process down? I think thats a broad statement for the people that have made a lot of power on 7 bolts and yet they havent crank walked. Any opinions?

Personally if every 7 bolt walked then there would be recalls and no one would have one in their car yet start adding mods so they make power. There are a few people that have stuck a lot of money into their car and run 7 bolts. Look at Shane, he's making great power on his 7 bolt and he has little to nothing in it for machining. Brian made good power on his stock 7 bolt before it crank walked but it was stock so I can see why it happened. So I dont understand how that statement can be correct.

I want to hear some opinions first before I start this project. Am I wasting my time?

Discuss...

[Pimpin Dsmstyle]

Alright, so not EVERY 7 bolt making power has walked. But it seems pretty unavoidable. JOSH WAS EXAGERATING, aka wrong.

You dont NEED a twin disk, sure a regular clutch will work.. till it walks

For the cost of what you are paying, it is worth trying. However, IMO ( no engine builder here, just read alot) if you dont make sure that girdly is PERFECT, if you use a heavy clutch, and you dont torque plate with machine work, I THINK it will walk in just a matter of time. Personally I think it will walk either way with you building it in your garage / shop thing.

You picked and chose my words and neglected to say I didnt know this wasnt actually being built for a race car. You mentioned it was for fun, that is great. It will be fun. Then it might walk and leave you stranded at the track yet again.

This point IS NOT PROVABLE. Many have tried, no one has succeeded. There is no real fix for it, and no one can stop it from happening. You used shane as an example? That motor has relatively low miles as far as I know. Bartons motor walked possibly because of the power he made. What about Chris? That motor didnt last long and every precaution ( besides the clutch ) was taken. ( the old one, the new one seems to be working out)

- Once again, I am no engine builder, and I have not seen this first hand. I have read alot and heard alot. I just dont see the point in throwing money into a 7 bolt when you dont have to.

[EclipseGST]

You said it will walk after the first day...

The reason I am doing this is cause I picked up the block, crank, rods and pistons for $50 and a valve cover. I could really pass it up for a good time. Its been balanced and blue printed and is all ready to go, I just need to pick up bearings. It also has ARP rod and main bolts. I'll spend another $100 on it in bearings and be done. $150 + some time for a built 7 bolt is worth it I think.

[Pimpin Dsmstyle]

How about the crank that is probably scoared? I can't remember, but I've seen it and I think it needed to be fixed or replaced.

I dont have the conversation anymore, but again I'm sure you were taking that out of context.

[EclipseGST]

Originally Posted by Pimpin Dsmstyle

How about the crank that is probably scoared? I can't remember, but I've seen it and I think it needed to be fixed or replaced.

I dont have the conversation anymore, but again I'm sure you were taking that out of context.

Crank is perfect... One of the rods was scored but I have a different one already. I have the conversation if you want it Josh~

[Jakey]

Originally Posted by EclipseGST

I have the conversation if you want it Josh~

What clutch was Barton running with his 7 bolt? I can't remember, did his motor actually crankwalk or spin a bearing?

[JET]

Originally Posted by EclipseGST

Crank is perfect... One of the rods was scored but I have a different one already. I have the conversation if you want it Josh~

It spun a rod bearing but the crank is perfect? What scored the rod bearing then? Why wouldn't you just replace the rod bearing, unless the bearing welded itself to the crank and actually spun inside the rod. In that case, the crank would definately not be perfect. Has the crank been ground undersized possibly?

I would stick with the DXD and see if it will hold the power. Also install a clutch bypass switch so you don't have to have the clutch in on startup.

[Pimpin Dsmstyle]

Im pretty sure post #12 and #13 werent me (josh). I dont know exactly what that shit is about?

[Pimpin Dsmstyle]

The crank is not perfect? The rod bearing spun and was thin as hell along with a burnt eagle rod after the accident, but did not melt to the crank. I should know because it was my engine and I did this. I basically just went 100% wot when oil was not normal temp and this is what caused the failure. Stupidity. The crank was polished and re-done, but when he builds it he still needs to install rod bearings and check clearances to see if in spec. Needs to be balanced as well. Then what the heck, give it a try!

[dumb_ricer]

I will agree that the actual CAUSE of crankwalk is not known. Yes, Chris Carreys motor did walk but he was also running a ACT 2900 so once again, that could have been a cause.

What people DO know, is that a lighter pressure plate will prolong the life of the thrust surface, which is why a Twin Disk is such a good idea on a built 7 bolt. I am not saying it is needed, because some people do fine on built 7 bolts for a long time. But the fact is, once again that NO one really truely knows what is causing walk on the 7 bolts. Many theorys are out there, but there is no definite answer.

Who knows, for a good price its probably worht it to try.......BUT I still would never build a 7 bolt or even put one in my car! When there is a better option out there (6bolt) for minimal amounts more work then why go with something that has proven to be unreliable.

And as far as Shanes, It seems like he has never gotten much over 200 miles on his built motors before something breaks or he decides to revamp his set up.

[scheides]

How much power are you planning on putting down? Just go with something with as little pedal pressure as possible. I have a DXD as well, and I used to have an ACT 2100. The DXD pedal pressure is *much* less than the 2100 was, and it is supposed to hold as much or more power as a 2600. I'd stick with the DXD if you're not going *too* big.

[EclipseGST]

Originally Posted by scheides

How much power are you planning on putting down? Just go with something with as little pedal pressure as possible. I have a DXD as well, and I used to have an ACT 2100. The DXD pedal pressure is *much* less than the 2100 was, and it is supposed to hold as much or more power as a 2600. I'd stick with the DXD if you're not going *too* big.

I dont really know yet. I have the FP58 that I am getting rebuilt by Deisel components so I plan on running that. Probably going to flow around 55lbs/min so I'm not maxing out the turbo. Maybe 60 on occation. I just want to see what I can do with the small amount of money I have in it. I'm talking less than $1000 for clutch (maybe), injectors, and dsmlink, then be said and done with the parts I already have.

[dsm95gsxer]

I like the idea, and would like to try the same route. Granted it isn't that much more difficult to throw in a 6 bolt but it would be easier to use the engine it came with. My 7bolt has 108,000 miles and it and hasn't skiped a beat I'm also not making gobs of power with my 16g set up either. For that price why wouldn't you. If you decide not to let me know and I'll buy the parts off of you.

[AJ]

Just build the 7 bolt, remove a bolt and call it a 6 bolt. That's how Shane keeps his going. lol

[Pimpin Dsmstyle]

Originally Posted by EclipseGST

Well I picked up a 7 bolt motor from a buddy, Eagle rods and Ross pistons. Just going to build it for fun and see what can happen before the end of the year. So I been told by a member here that I need a Twin disk no matter what. Personally I think the DXD clutch I have now will be just fine, maybe get the 6 puck clutch from Southbend to hold more power, but running a twin disk is going overboard in my opinion.

Also this person thinks that all and every 7 bolt that makes power will crank walk no matter what. So if its going to get CW no matter what then why should I get a twin disk to slow the process down? I think thats a broad statement for the people that have made a lot of power on 7 bolts and yet they havent crank walked. Any opinions?

Personally if every 7 bolt walked then there would be recalls and no one would have one in their car yet start adding mods so they make power. There are a few people that have stuck a lot of money into their car and run 7 bolts. Look at Shane, he's making great power on his 7 bolt and he has little to nothing in it for machining. Brian made good power on his stock 7 bolt before it crank walked but it was stock so I can see why it happened. So I dont understand how that statement can be correct.

I want to hear some opinions first before I start this project. Am I wasting my time?

Discuss...

Jason found the blue print for that engine, it spun a bearing, never walked! He tried to fax, but someone was answering the phone. CALL JASON SO HE CAN FAX BLUEPRINT. Bore size-3.376 Net Dia. 3.371
C.H. 1.375
Ring Grooves 1.5mm 1.5mm - 3mm
Ring Lands .350 .185 .085
PIN .866 2.500 DBL
Net dome cc's: -12.10
Dome height 0.000 Dish Depth: 0.123
Int V.P. Dia. 1.400 Depth: 0.120
Exh V.P. Dia. 1.300 Depth: 0.080

These are the #'s from blue print. Ross Racing Pistons spec sheet.

[Pimpin Dsmstyle]

Originally Posted by Pimpin Dsmstyle

Jason found the blue print for that engine, it spun a bearing, never walked! He tried to fax, but someone was answering the phone. CALL JASON SO HE CAN FAX BLUEPRINT. Bore size-3.376 Net Dia. 3.371
C.H. 1.375
Ring Grooves 1.5mm 1.5mm - 3mm
Ring Lands .350 .185 .085
PIN .866 2.500 DBL
Net dome cc's: -12.10
Dome height 0.000 Dish Depth: 0.123
Int V.P. Dia. 1.400 Depth: 0.120
Exh V.P. Dia. 1.300 Depth: 0.080

These are the #'s from blue print. Ross Racing Pistons spec sheet.

PS, CAREFUL INSTALLING THE PISTONS. Dont want to have to order those dahm rings again for these custom pistons.

[TurboDomestics]

What the hell is going on here!!

Since we're on the subject of CW, i wanted to clear something up, 1G 7 bolts dont walk, right? SO whats wrong with them other than the smaller rods? If you built a 1g 7 bolt, it would be just as strong as a 6 bolt right? or am i completley wrong

[dumb_ricer]

My friends 93 TSi AWD crankwalked, but that is a rare occurance.

I could have sworn I read something that there is a lack of tranny mounts supporting the 2g transmission in the right places, or not supported at all. I havent worked on many 2g's before, but I do remember reading something about that.

No one knows why 2g 7bolts walk so often, and no one probably ever will.........

[EclipseGST]

Thanks Jason... I gave my you my parents fax number which also happens to be the home phone number, they werent expecting a fax at 10:30pm so thats why they were answering it. I'll give you a call tonight and let you know when to send it.

Originally Posted by dumb_ricer

My friends 93 TSi AWD crankwalked, but that is a rare occurance.

I could have sworn I read something that there is a lack of tranny mounts supporting the 2g transmission in the right places, or not supported at all. I havent worked on many 2g's before, but I do remember reading something about that.

No one knows why 2g 7bolts walk so often, and no one probably ever will.........

I dont know about that. 2g's have 3 tranny mounts so it is definatly supported well. The only thing I could manage to think of out of that info is if the place you read that from meant the engine has a lack of mounts. I could see the crank being forced up by the weight of the engine pushing down on it while attached to the tranny considering there is only 1 motor mount on the engine (drivers side). Then by the crank pushing up it crushes the upper thrust bearing and while pushing in the clutch it moves the crank over and crushes the sides also. There for the crank is just flopping around in there. This is the only thing I could think of but if that was the case I think a lot more cars would have it.

[dsm95gsxer]

http://www.magnusmotorsports.com/crankwalktheory.htm

One of the better crankwalk articles.