How much over bore can a production 4.1 handle?

[Ted]

30, 40, 50?

Or should I say far have you guys gone with your motors?

 

[Quick6'n'-K.C.]

My 4.1 was bored out .040 and it never had overheating issues.

Of course the idiot who built it installed the rod caps backwards and ruined all the bearings after 10,000 miles, i thought it spooled my TE45a with a .85 exhaust housing faster than a stock 3.8 with a stock turbo and D5 convertor. I had a 3800-4000 convertor.

BW

 

[sixgun86gn]

Mine had 4.020 pistons in it and the stock bore is 3.965.That comes out to .055 over.Never overheated.Even driving an hour to the track both ways.