confused newbie rebuild

[ant95talon]

Hi I have a 95 Talon with a 98 GSX engine that I purchased which is in pieces. So I have decided to do a total overhaul on the engine. My goal is in the 400-500hp range. I started talking with some people who said that they have experience with the 4g63. I was told the best approach would be to do a 6 bolt swap. I started to do some research and talked with others about my plan. I was informed that all i would have to do is swap out the crank shaft and clutch pressure plate, fly wheel, and of course the head. Here is were I was thrown into utter confusion. I was informed that the 6 bolt head would bolt right up with a 7 bolt block, then I was told that the head would have to be machined to enlarge the holes for the head studs. So, I have been thrown back and forth trying to figure this out. Do I need a 6bolt head or would the 7 bolt head I have do just fine. I need someone to set me straight. HELP ME ###.

 

[bryanwheat]

Stick with your 7 bolt. Just dont ride the clutch because thats the reason why they get crankwalk. I just had my machine shop explain it to me yesterday and im going to try my best. 7 bolts have a thrust bearing, 6 bolts have the thrust bearing but its built into the main bearing, making it less prone to wear side to side. And when your constantly riding the clutch (even more so with a performance clutch because of the added pressure) it is pushing the crank slightly to a spot where the thrust bearing isnt getting oil, which makes it wear more. After enough time of riding the clutch and low oil flow to the thrust washer, it wears too much and thus crankwalk is born. So all in all as long as your not riding the clutch you'll be fine with a 7 bolt.

Actually 1g and the earl 2g 7 bolts use a thrust bearing that is built into the main bearing just like the 6 bolt, so that theory is out the window. The split thrust bearing that DOESN'T fail is in the late 2g blocks. According to your machine shops theory the late 2g blocks should be the ones walking, not the early blocks. Has your machine shop actually cut these blocks into slices to look at the oiling passages and tested the oil jets? Until they do extensive research than it is just theory.

 

[renogsx]

OP you would buy 4 bolts to plug the holes M12 x 1.25 pitch and at least 12MM in length. Before you do that make sure to do your research -general consensus is to leave them in even with forged pistons. The worst could happen is that it's more reliable. If your doing a stroker (which may interfere with the nozzles) get the EVO squiters no clearancing required.

They are to cool the piston tops not the pin bushing

People plug them for more stable oil pressure to the mains. As far as cooling the piston a proper tune would be the better way to handle that.

 

[jimbob_843]

Tooshay sir. The only other sensor i can think of is the barometric pressure sensor on the drivers side of the intake mani, whether its plug is the same i dont know. I agree that the 6 bolt is well worth the time and effort, as i have done the swap.
And NO ONE has a dead on cause of crankwalk, even magnus. And they cut a block in half to study the causes. On their site they state there is no simple cause of it only theories.

 

[renogsx]

Stick with your 7 bolt. Just dont ride the clutch because thats the reason why they get crankwalk. I just had my machine shop explain it to me yesterday and im going to try my best. 7 bolts have a thrust bearing, 6 bolts have the thrust bearing but its built into the main bearing, making it less prone to wear side to side. And when your constantly riding the clutch (even more so with a performance clutch because of the added pressure) it is pushing the crank slightly to a spot where the thrust bearing isnt getting oil, which makes it wear more. After enough time of riding the clutch and low oil flow to the thrust washer, it wears too much and thus crankwalk is born. So all in all as long as your not riding the clutch you'll be fine with a 7 bolt.

Not true. Early 7 bolts come with a single thrust and bearing combo that is more prone to "walk" than the 98 and up design that was used in all the later evos

Tooshay sir. The only other sensor i can think of is the barometric pressure sensor on the drivers side of the intake mani, whether its plug is the same i dont know. I agree that the 6 bolt is well worth the time and effort, as i have done the swap.
And NO ONE has a dead on cause of crankwalk, even magnus. And they cut a block in half to study the causes. On their site they state there is no simple cause of it only theories.

Its clearly an oiling issue and I believe magnus doesn't use oil sprayers on there 7 bolt motors at least on the 2.4 they do not drill and tap the block.

 

[Awesomewheeldrive]

Okay then i stand corrected but even if it isnt because of split bearings, the only thing putting.pressure on the crank would be the drivetrain. Im trying to stick up for the 7 bolts because, crankwalk can happen on any vehicle, but my personal theory for the7 bolt getting the bad rep about crankwalk is because the 2g's are "fast and furious cars" so all the douches wanted to be like the movie and got 2g's, beat the hell out of them and now bam! A bunch of 2g's have crankwalk!

 

[bryanwheat]

Tooshay sir. The only other sensor i can think of is the barometric pressure sensor on the drivers side of the intake mani, whether its plug is the same i dont know. I agree that the 6 bolt is well worth the time and effort, as i have done the swap.
And NO ONE has a dead on cause of crankwalk, even magnus. And they cut a block in half to study the causes. On their site they state there is no simple cause of it only theories.

There is no such sensor on any 1g or 2g 4g63. The baro sensor is build in to the maf sensor. As i said the only things on the intake manifold are coil pack, ignition transistor and mdp sensor for a 2g.

 

[rebuild4g63]

And the idle air control sensor motor attatched to the throttle body attatched to the intake mani

 

[bryanwheat]

And the idle air control sensor I think or is that on the throttle body. same area

That is on the throttle body. They are same between 1g and 2g also.

 

[NHerron]

People plug them for more stable oil pressure to the mains. As far as cooling the piston a proper tune would be the better way to handle that.

I think you mean more pressure. A balance shaft delete would bring up pressure enough you don't need more by plugging the jets. As I stated before, all it will do is be more reliable. I beg to differ dumping extra fuel for cooling is better than keeping free oil jets unless your talking about alternative fuels -ie methanol.

On a 1g 6 bolt and 7 bolt this will work, on a 2g 7 bolt the oil jets are in the main journal casting of the block. I just tap the hole and install a set screw in them or install new oil jets.

Thanks for catching my mistake, I got a little distracted since we seem to be talking about all years of DSM 4G63 haha.