6 bolt vs. 7 bolt [merged] 6bolt 7bolt 6-bolt 7-bolt six bolt seven bolt

[asdfzxc]

All 6 bolt vs. 7 bolt threads are merged here.
How do I tell if I have a 6 bolt or a 7 bolt?
Will x part from a 6 bolt fit a 7 bolt?
Will x part from a 7 bolt fit a 6 bolt?
Which one is better?
How do I swap my x bolt for an x bolt?

What is the difference between 6-bolt and 7-bolt engines (aside from the obvious - 6 vs. 7 bolts connecting the flywheel )

Is there an advantage over either of the two engines?

Thanks,

-Mike

 

[EC17PSE]

Ok so I've spent a few hours reading most of this skipping a few only hear and there! And I understand a lot but I've now got a few questions!

What problems are in the 2g heads that the 1g heads don't get? as some1 said that they do? I know about the flow in the 2g's better and 1g better top end! And are the cas in the same place as the 2g head?

Now the 2g bottom end has 2 crank sensors and the 1g has just 1 is that a good thing or bad thing? Plus the 2g has some girdle in it! And you can buy the girdle for the 1g but any issues on that? And the transmission do you have to have the 1g tranny or can you keep the 2g setup? Would you have to change anything other then internal! Say an auto can you directly bolt up the 1g auto with the 1g tcu? Or as I asked can you keep the 2g inplace? As then you would have to change axles and everything aswell right? I think that's the main questions I also wanted to add! And when people say they cleared cw I hear that aswell in the later 97-99 cars but here in the u.k all the evo 1-3's don't get crankwalk and I'm not sure why as when I asked some they laughed! Lol just to add supra's are very prone to cw aswell but they still run 1200hp so I think its all in the build and what you use and short cut's you take? Anyway that's it from me if there is a guru out there that has my answers that's awsome as I've read a lot and don't wana read anymore! My eye's are square now haha. Cheers folks

 

[red_devil]

Dont know if this has been asked before but is there any info on the "JDM" 4G63? I called up the place where my motor was bought and they said that the engine was from Japan. It has a 95-96 cas and is a 7bolt with a 2G head. Everything looks about the same except the water pipe is a little different than the one in my old GST. The turbo was a t25 but it could of been taken off the original motor. Anyone know what car it came out of and if the build quality (less prone to cw) is any better than the ones made over here? Just curious.

I would also like to add that the 3 piece bearings in the later block was just Mitsu being cheap and using them to help reduce the problem and not fix it since there are reports of 99 blocks walking. But you guys with the 99 blocks when you order new bearings from ACL or Clevite are they the same as the oem?

Im planning on building a 7 bolt anti walker in which I will use Tri metal ACLs, Align honed crank with arp main studs, deleted oil squirters, Balanced rotaing assembly, bse, and a Fluidampr pully running with royal purple oil.

 

[blowinsmoke95]

okay guys after reading through all of this rambling... i need a simple and direct answer....
CAN YOU USE A 7 BOLT CONNECTING ROD ON A SIX BOLT CRANK and why not if not.... thank you...

 

[samnumba1]

I have no response to that, but I have a question related that could be answered congruently...?

Is there a difference between 6-bolt and 7-bolt rod bearings?

ACL, Top Line, Clivite all separate 6 and 7 bolt but the parts stores show the same part number... I know the journal diameter is the same and possibly have width differences.

Not to good with CAPS, but I see MD195939, MD195940, MD195941. Anyone know?

 

[v8s_are_slow]

okay guys after reading through all of this rambling... i need a simple and direct answer....
CAN YOU USE A 7 BOLT CONNECTING ROD ON A SIX BOLT CRANK and why not if not.... thank you...

I know you can use a 6 bolt rod on a 7 bolt crank. Dunno if it'll go the other way around or not though. Only question I have about your question is, why the hell would you want to???

 

[blowinsmoke95]

I know you can use a 6 bolt rod on a 7 bolt crank. Dunno if it'll go the other way around or not though. Only question I have about your question is, why the hell would you want to???

its not the fact that i want to... i asked this question beacuse the jackass who had the car before me put a 7 bolt rod on a 6 bolt crank along with 3 6bolt rods... it has rod knock and i just want to get this car running before winter hits... i dont need it to be RELIABLE i just want to drive it... since owning the car, i've only put like 2.5 miles on it... also, not worried about the crank, i plan to do an entire swap when money permits...

Also, anyone know where to get the rubber o-ring that goes between the water pump and the tube that runs across the front of the block???

 

[tsihottie]

7 bolts get crankwalk, 6 bolts don't.

You are wrong.

Also, crankwalk is more common or heard of on either of the two(mostly 7bolts) with a manual tranny. This is caused by the clutch/flywheel being pushed in against the crank constantly, thus causing the crank to weaken and then you get crankwalk.

 

[95talongirl]

Actually, ANY engine can crankwalk. "Crankwalk" is the premature failure of the main thrust bearing. Both auto cars and manual cars suffered from it.... there's many theories as to why certain year 2g cars seemed to suffer more from it; form oil squirter design to mis-casted blocks. I agree tho, I wish that word would just dissapear because its caused so much confusion for no real reason... then EVERYTHING gets blamed on "crankwalk".

 

[Flip90gsx]

I'm getting a bit confused on what i'm reading. Mainly because it appears everyone is trying to get a 6 bolt swapped in. Needing help with this. I bought an eclipse off a guy and with a snapped timing belt. He told me it was a 93 gsx. After I bought a 7 bolt motor to swap in, I find out it is a 90gsx on the regristration. (Made the deal that much better) To my suprise, I rip the head off wanting to keep the six bolt. Pistons are in excellent condition and there is no cylinder wall wear (He didn't tell me it had been rebuilt). I checked the oil pan, it is a 6 bolt. The valves made contact, but I can smooth out the slap marks on the pistons with ease.

My question is, can I take the head off the 7 bolt and swap it right on the 6 bolt? Can I keep the 90 throttle body or does all the 93 parts, block up, need to go with it? Any advice would be appreciated.

 

[97Boosted]

I'm getting a bit confused on what i'm reading. Mainly because it appears everyone is trying to get a 6 bolt swapped in. Needing help with this. I bought an eclipse off a guy and with a snapped timing belt. He told me it was a 93 gsx. After I bought a 7 bolt motor to swap in, I find out it is a 90gsx on the regristration. (Made the deal that much better) To my suprise, I rip the head off wanting to keep the six bolt. Pistons are in excellent condition and there is no cylinder wall wear (He didn't tell me it had been rebuilt). I checked the oil pan, it is a 6 bolt. The valves made contact, but I can smooth out the slap marks on the pistons with ease.

My question is, can I take the head off the 7 bolt and swap it right on the 6 bolt? Can I keep the 90 throttle body or does all the 93 parts, block up, need to go with it? Any advice would be appreciated.

no you cant just swap the head "right on" you need to ream out the head stud holes. the 7 bolt has 11mm headstuds and the 6 bolt has 12mm. Im pretty sure you can use the TB, its bigger than the 7 bolt TB from what i remember.

 

[Flip90gsx]

Thank you. Gonna be starting on it next week. Another dsm shall be making it's presence out on the streets.

 

[KC2RPM]

Ok so after reading the article on vfaq about the difference in the oil pan between a 6 and 7 bolt. I noticed what appears to be a 6 bolt pan, but im not 100% sure. I would just like some confirmation that I really do have a 6 bolt. THANKS!

You must be logged in to view this image or video.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

 

[IceMinion]

We need more pictures mate! Are you trying to figure out if you own a 6-bolt engine? or just the oil pan?

There is a "Hump" or "Bump" on ALL 7-bolt engines on the front case, the oil pan bolts to the front case and it too has a bump.

Based on those pictures, it looks like that is a good ol 6-bolt

 

[9!'clipseDOHC]

Since you have a 2g, you would obviously have to have had an engine swap to even possibly have a 6 bolt. So first, is this the factory engine or has it received a transplant?

 

[KC2RPM]

I bought the car last summer and I would imagine the motor may have been swapped out for a 6 bolt. Im not sure, thats why im asking everyone else! haha

 

[BIGMIXX]

Looks like a 6 bolt to me, but like stated above, have the mounting hump? Or can you see the vin on the block? Best of luck, bet it's feeling like christmas huh?

 

[snowborder714]

This is the easiest way to tell.

You must be logged in to view this image or video.

The image above shows a 7 bolt. If it was a 6 bolt, the front case/oil pan flange would not have that dip in it, but would instead be straight across. I don't recommend people go by humps/bumps in the oil pan any more since most of them are dented everywhere.

 

[KC2RPM]

THANKS EVERYONE! HAHAA im so happy! ordering a td06 20G now!

 

[whos_the_master]

Very helpful!!!

 

[Gundyy]

i hear 6 bolt this and 7 bolt that... what's the damn difference? p.s. hence the newbie forum post

 

[nothingfiction]

it only matters if you have the 4G63 turbo engine
(could be wrong about the turbo part, but the 420A engine is a different platform and eludes us.)
You haven't listed what car you have, so i thought i would post that.

 

[Gundyy]

okay but generally speaking what's the difference? i'll most likely be getting a 97 Talon TSI with the 4G63 so...

 

[DWR-DSM]

okay but generally speaking what's the difference? i'll most likely be getting a 97 Talon TSI with the 4G63 so...

7 Bolt that year unless they swapped to a 6 bolt

Here is everything you gonna need to know or ask about the difference and etc.

http://www.dsmtuners.com/forums/new...-7bolt-6-bolt-7-bolt-six-bolt-seven-bolt.html

 

[rlacasse1]

It will more than likely have a 7 bolt unless someone swapped it over to a 6 bolt. The bad thng about a 7 bolt is that they crankwalk alot. Which is not good.

It is obvious to tell them apart. 7 bolt has 7 bolts holding the flywheel on the crank. 6 bolt has 6 bolts holding the flywheel on the crank.

 

[asb2106]

Very similar motors really..

THe reference to 6 bolt and 7 bolt refer to the amount of bolts on the flywheel.

The internals(mainly rods) on the 6bolt, are stronger.

The 7 bolts are known for crankwalk.

The 6 bolt is a superior motor, but not by much.

6 bolts were in production GSTs, GSXs and TSis from late 89 to 92. 93s and up use the 7 bolt.

EDIT - I type slow, el oh el!!