[DZAUTO]

When I build an engine, I always buy new rod bolts. Period. But I used to always re-use the main cap bolts. As time went by, and I built more and more engines, I began to see some broken main cap bolts when I tore them down. So I started replacing main bolts also. I just bought another SB400. It has 150Kmi on it. It came out of my cousin's 75 Elky and was running just fine (using some oil). I tore it down last night and discovered the head of a main bolt had broken off. How long? Who knows? My whole point here is if you are planing on an engine rebuild soon, don't cut corners here. Replace the rod/main bolts, even if it is a stock rebuild. Who knows, if you re-use your old bolts, a bolt head may pop off as soon as you button up the pan. And you would never know it. Well, maybe later.

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Tom Parsons

[This message has been edited by DZAUTO (edited 12-16-99).]

 

[Gene Chas]

Whoa. Good tip Tom. I was always told ( and did ) replace the rod bolts before we did the big ends. But mains? Good tip. I guess those windage studs are more useful than I thought.

 

[Stan]

I was told by the machine shop that if you went with new main cap bolts they would also need to be mainlined as well 'cuz of the different materials used now and the fact that the bolts will torque and shift differently?

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Stan Hanek
'66 SS - 396 4 sp.
[email protected]

 

[Gene Chas]

Stan, we always noticed that the big end of the rods went out after we switched bolts, sometimes as much as 1/2 thou. I always kinda figured it was from all the banging around. But mains? Interesting. Whatdya think tom, maybe Mr. Bill has some insight on this.

 

[SS396ELKY]

Well think of it this way... Where is the most stress on an engine? Rotating assembly and heads. I replace all the bolts with ARP bolts even if it is a mild build up. Rod, Main, Head and flywheel bolts. I send the block and crank in with all the bolts. I have all the bolt holes cleaned with tap. Just a few extra precautions I take.

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JR
70 396SS El Camino #'s Matching.
69 396SS Chevelle, project "Street Bruiser"
H-D Ultra Classic E-Glide
72 Chevy C20 Flatbed, $500 DRMO sale. Thanks Uncle Sam
I live to own toyz...

 

[69SSRat]

Well My BB rebuild I just completed and presently installing I replaced all rod/main bolts with ARP main went with studs They checked align bore and was no movement.I think you should check but machining is not required.

P.S. I went with stud they say it keeps mains from walking better than bolts.