DSM 6&7 bolt differences
 

i've got a 95talon tsi 7bolt i'm looking at buying a set of rods and pistons for a "6bolt" can i use those in my 7bolt or do i have to run the 6bolt crank and crap???? kinda a newbie at dsm's. "honda guy here"
I've heard on 7bolts you have to drill a hole in the main bearing race to eliminate premature bearing wear, can anyone second this and if pics would help????
What kind of options are out there for aftermarket thrust bearing i've heard a couple different materials, has anyone had good experiences with a certian company or brand???
Any tricks and tips for building my 7bolt would be GREATLY appreciated.
thnx for the feedback guys.

Re: DSM 6&7 bolt differences
 

Throw your head on a 6 bolt block and call it a day

Re: DSM 6&7 bolt differences
 

Why are you building a parts car?

Re: DSM 6&7 bolt differences
 

My VR4 has ran perfect all fall, winter and spring so far and never had a problem besides the radiator cracking a week after I bought it. The guy before me just patched it up with expoxy ::). After the new radiator it's been better then all my honda's. I'd say just get a 6 bolt shortblock and swap that in. Don't even hassle with that 7 bolt. Leather seats, awd, turbo 4dr's FTW!

Re: DSM 6&7 bolt differences
 

So, why don't you just buy some 7 bolt parts? douche bag :1

Re: DSM 6&7 bolt differences
 

differences are crank-walk and dependability no six bolt stuff wont work on a 7 bolt

Re: DSM 6&7 bolt differences
 

Just fgo out and get a 6-bolt block and build that up. The six bolts are alot stronger and you won't have to worry about crankwalk.
Do as he says haha. I have money put aside just in cvase my 7-bolt decides to take a walk. Just bolt on your head and get a new flywheel for the 6bolt :-) The clutch is the same as the 7bolt but the flywheel is different. Or you can get the 1st gen head and intake mani. It uses a larger throttle body and flows better.

Re: DSM 6&7 bolt differences
 

Running 6 bolt rods in a 7 bolt requires some machine work to the crank end of the rod. Many people do it swapping the stock 6 bolt rods in since they are quite a bit beefier than the stock 7 bolt stuff. If you are buying aftermarket, just get the right stuff. The big end has to be narrowed slightly to fit into the 7 bolt journals.

There are a lot of "fixes" for crankwalk, but most don't have enough testing to definitively say they are a 100% fix. IMO crankwalk is blown way out of proportion, its not as common as its made out to be and whenever something happens its the first thing they jump to. The only 100% proven fix IMO is the 6 bolt swap.

Re: DSM 6&7 bolt differences
 

6 bolt rods and pistons aren't gonna keep the engine from C'WALKIN' anyways...it's the 7 bolt crankshaft itself that is faulty, not the pistons and rods...a complete 6 bolt block can be had for relatively cheap...I left one at a house the last time I moved and went back to look for it recently, but unfortunately it's gone...I know where a RUNNING 6 bolt 4g63t w/automatic trans for $600 is at now, but I'm too lazy to go pull it and go through the hassle of shipping it to somebody...ME FTL

Re: DSM 6&7 bolt differences
 

If you want easy, just get a 6bolt motor.

A 2g head actually flows better than a 1g head, BUT the 1g tb and im flow better.

A 2g head on a isn't just take off the 1g head, and throw on the 2g head. There's something that needs to be changed with the CAS.

I'm not a dsm guy either lol

Re: DSM 6&7 bolt differences
 

The 1g head has MUCH larger ports than the 2g head. Matching the 1g manifold to a 2g head requires the removal of a lot of material. It is MUCH more common to swap a 1g head into a 2g car than the other way. To use a 2g head on a 1g block requires drilling the head bolt holes out also. The geometry of the 2g is better, and can be ported to flow better than a 1g, but its not that way out of the box. 1g head is more biased toward high rpm, and you lose a decent amount of low and midrange when swapping to one from the loss in velocity.

Re: DSM 6&7 bolt differences
 

Meh some people never have there 7 bolts crankwalk some people like my friend manage to have 3 7bolts in a row crankwalk on them :X

Re: DSM 6&7 bolt differences
 

Now that is some fucked up luck.

Re: DSM 6&7 bolt differences
 

well i dont exactly have an extra $1100 to go blow on 7bolt pauter rods and srp Ps darksol, and i know pistons and rods arent the cure for crankwalk thankyou very much, but i was asking what it takes, like rod journal size from 6to7 and is it possible or just out of the question thnx Aero. does anyone know how much to take of .01 .02 .03???
dont have parts in hand or i would figure it out. thnx guys
I have the 7bolt crank and block and have all the internals for a 6bolt so i want to make it work.

Re: DSM 6&7 bolt differences
 

7 bolts suck. 6 bolts are great. If 6 bolts had SBC bolt patterns and fit Honda distributors I'd run nothing else.


Not that it, or aero's alternative perspective, matters. The valves are so shrouded it makes no difference. :)

Re: DSM 6&7 bolt differences
 

right on if only they didnt come in such a clusterfuck tank of a card :3

Re: DSM 6&7 bolt differences
 

I hear yah. My VR4 is a ------- tank at like 3300lbs. :X It's suprisingly how easy it is to get these boats to run 13's for so cheap though. BUt then the DSM reliability issue peaks it head in and then :X

Re: DSM 6&7 bolt differences
 

Rod journals are the same diameter, it is width that is the issue. For some reason I can't find the exact dimensions, I used to have them. You should be able to measure the width of the two and determine how much material to remove. If that doesn't work for you I'll do a little more looking.


The 98-99 7 bolts aren't bad, they moved to the separate thrust washer and eliminated most of the crankwalk issue. The 7 bolts do have some positives, one piece main girdle that stiffens things up for one.

Re: DSM 6&7 bolt differences
 

got 2 buddy's with a gsx, and tsi.. think there both 97's. and yes, both have crank-walked. DSM FTL

we got a local shop here that does nothing but dsm's, they wont even touch the 7 bolt motors just from the crank-walk issues

Re: DSM 6&7 bolt differences
 

+1,000

You can run 1g rods in a 2g 7bolt crank/block, the wrist pin diameter on a 6bolt rod is 21mm, it must be enlarged to 22mm 7bolt size. thats it.

1g head has larger ports and FLOWs better at lifts higher than .300 than the 2g weenie ass head.

I wish i didnt have all this useless dsm knowledge stored up. Someone hit me over the head.

DISCLAIMER: I do not support the building of any dsm whatsoever. They are parts cars for me to poop on. :P

Re: DSM 6&7 bolt differences
 

I'm not even gonna begin to describe what's wrong with this thread.... Have fun with your crankwalk machine of death

http://www.xtreme2k2.com/images/crankwalk.jpg

Re: DSM 6&7 bolt differences
 

Rob... Mikey appreciates you. :)

Re: DSM 6&7 bolt differences
 

I know, but its like winning the special olympics... :1

Re: DSM 6&7 bolt differences
 

Nah, the Colt doesn't weigh enough to bring out the massive driveline deficiencies of the transmission, and if the wiring isn't up to snuff I'll make him go standalone and construct a vehicle harness out of spare Honduh loom. At that point, there is nothing wrong with his Mitsu I can think of. :)

Re: DSM 6&7 bolt differences
 

You just described what you have to do to run 2g pistons on a 1g rod which is another common mod. To run the 6 bolt rod in a 7bolt the big end needs modified not the wrist pin end. It needs narrowed a few thousandths.

Re: DSM 6&7 bolt differences
 

aero, you and Hitchhikkr need to have babies, and lock them into a dark basement full of machining equipment, metal stock, and DSM transmissions until they figure out hwo to fix those things for good.

Re: DSM 6&7 bolt differences
 

lol your 100% right, i read thru too fast and misunderstood what he wanted to do. My bad. Im neck deep in a 911 turbo and been a bit scatterbrained most of the day. :1

Re: DSM 6&7 bolt differences
 

Some people just won't listen ::)

Re: DSM 6&7 bolt differences
 

thanks guys for clearing up the 1g/2g head flow thing, cause that's what i always thought too, but my friend who's been obsessed with dsms since he was 15 (is 20 now) convinced me that through extensive research it was determined that 2g heads themselves are better.

i'll have to correct him.

Is it just because the ports are larger on 1g heads? Is the shrouding of the valves as large an issue on both heads? Some more info would be great, I like dsms despite their pitfalls.

Re: DSM 6&7 bolt differences
 

Friend of mine in ATL has a flow bench, did some extensive testing on all the 4g63/61 heads, valve shrouding is a problem if you want big manly power, but for street cars, its not that big a deal. He gave me a printout of his findings, but i cant seem to find it at the moment, so believe me if you want. His results showed that the 7bolt 2g heads flow better at lifts at and below .350 we are assuming the smaller port ie velocity is the cause, looking at the heads, the 1g 6bolt head has larger ports, but the cross-sectional area near the valve is basically the same. At lifts above .400 the 6bolt head owns the 7bolt. I wont even mention the 1.6l head, since it wasnt even comparable to the others. Basically what it boils down to is that unless you have a big nasty cam, and are bouncing the limiter above 8500, yeah the 7bolt heads are probably gonna flow better/more. I'll post that stuff if I can find it. :6

JD's right, the 4g63 is a badass engine, but everything attached to it blows. The truth about the trannys is that there isnt a problem with them. Its the cars that are too heavy, even stock to be anything more than a pain in the ass. You have to consider, the w5m33's and F5m33's were designed for the evo and cyborg, neither comes close to the wet weight of a dsm. Yeah there was a problem with the blocking rings in the early cars, but thats just mitsu cutting corners like they always do...

Re: DSM 6&7 bolt differences
 

ah ha! so he was partly right. that's GREAT info, thanks a bunch!