2.0 Shortblock is tight!!!!

[FireyIce01]

Do WHAT??!!???

Good god.

Apparently it's a common practice in drag racing... *shrugs* seems a couple other people have reccomended doing the same thing, though one suggests a brillo pad instead... I personally would say use some 000 steel wool if you're looking for something really fine... course, with something that has as tight of tolerances as the 4g63.... I would probably take it back to the machinist and have them check it out, hopefully give some sort of guarantee on their work...

 

[goshred005]

Do WHAT??!!???

Good god.

get it checked

 

[Defiant]

Apparently it's a common practice in drag racing...

Ah. Yes, where an engine has an intended life of maybe three miles.

Not on the street. And never on the "bearing surface".

 

[FireyIce01]

Ah. Yes, where an engine has an intended life of maybe three miles.

Not on the street. And never on the "bearing surface".

Yea, more likely 3 runs, and I never really thought about that... I just made the assumption that he meant the back side of the bearing, not the part that the crank rides on... cause it is a surface... *shrugs*

 

[half-cocked]

I would get that rod clearance to about .025", same with the mains.

You sure? The standard value is .0008" - .020" with a MAX of .040"

 

[bastarddsm]

Uh, how many of you guys have worked in a machine shop that built high performance motors. Let alone put them together every day.

.020 rod bering clearance what the hell is wrong with you guys.

Yes, most assembly lube is sticky and thick so it stays on the bering surfaces untill it is washed away with engine oil. that way the berings arn't dry.

Just because you put one dsm engine together dosn't mean you know anything about putting a motor together.

 

[half-cocked]

I never said I was an engine builder, I am putting the engine together per the FSM specs. If .020" rod bearing clearance what is recommended I'll pull them and redo them. Any suggestions on how to increse bearing clearances?

 

[98TsiAWD]

You sure? The standard value is .0008" - .020" with a MAX of .040"

Yeah, you are gonna want almost .025", I wouldnt go more than that however. This will allow a little more oil. Spinning a rod bearing at high rpms is pretty common on a stock setup 4g63. So A little more oil on the rod bearings wont hurt you. But in order to get a little more pressure to the rod bearings the mains also need to be toleranced out a little bigger.

To do this use a scrotchbrite pad on the BACK side of the bearings, Make full and even strokes so taht you are removing the same material off the entire surface. Do small amounts at a time, go buy alot of plastiguage.

 

[half-cocked]

Before I go another mission, would you reccomend this for a motor that would be extremely lucky to see mid 300 WHP figures? It wont see over 7000 RPM either, even those runs will be few and far inbetween. I ask only because this crank was used from another engine and it only needed a polish so I imagine the guy was had the same clearances I do now, and he had some mods.

 

[rcarrier]

Ok guys had it checked out, the clearance is .008 on the main bearing's, which is the minumum, the rods also checked out, and yes there is a guarantee with the motor, i am going forward with this project, i hope it all works out, thks for all the help!

 

[Maglin]

Wow that is very tight. Which is usually a good thing. Just take some extra care in break-in and let it have some cool down periods. Tight motors usually are very strong but can be hairy at break-in. Glad to hear they did pay attention and did blueprint your motor it seems.

 

[rcarrier]

Yea, they balanced and bluebrinted, went with 9:1 pistons, got me a head from busher, got 264/272 cams ,it should run pretty good, i was just scared with the motor tight and all,since this is my first engine i wanted to make sure everything was right!
(running 12's looking for 10's )

 

[FireyIce01]

Yea, they balanced and bluebrinted, went with 9:1 pistons, got me a head from busher, got 264/272 cams ,it should run pretty good, i was just scared with the motor tight and all,since this is my first engine i wanted to make sure everything was right!
(running 12's looking for 10's )

Well, I'd say you picked an excellend machine shop, cause it sounds to me like they did an outstanding job on your motor. Take pictures along the way, keep us updated.