4.1 out of the yard

[WH1Driver]

I found an 83 Oldsmobile in the yard with a 4.1. I thought it might be worth picking up to have since these are becoming rarer to come by. What years did the 4.1s have the rolled filled cranks. I remember hearing some 80s 4.1s did come with them. Not sure what years exactly. If one of you guys can tell me I'd appreciate it. THanks

 

[unboostedV6]

All years of 4.1 have the rolled fillet rods journals.
GB

 

[WH1Driver]

All years had them but not necessarily all 4.1s got the crank correct?

 

[KendallF]

Originally posted by WH1Driver
All years had them but not necessarily all 4.1s got the crank correct?

From the factory, the 4.1s all got the rolled fillet crank. If it's been rebuilt, it may or may not still have it. Between myself and a couple of friends, we've gotten 5-6 of them that way.

 

[WH1Driver]

Well I'll have to pull the pan and a cap to be sure I guess. Thanks for the info fellas

 

[WH1Driver]

What more out of this 4.1 can be used. Control Rods and what else in a turbo application? Pistons I assume will be too high of a compression and cast.

 

[Red Regal T]

I don't believe they all have a rolled fillet crank. Another problem is you can't pull the pan in the car. So you just have to gamble your work.

 

[WH1Driver]

I'm willing to take on the odds. I want the block anyway. Still wondering if I can use the control rods or pistons in it.

 

[CTX-SLPR]

Howdy,

Being a 4.1 owner myself the only thing that is different between the 4.1 and the 3.8 as far as I know is the block and pistons. Both for roughly the same reasons... the bigger 3.965" instead of the 3.800" bore. The rods are identical, so is the crank. The heads are probably early turbo 8293's instead of the later 8445 though I think some of the 84 4.1's got 8445's, mine didn't though. The main differences in the block are pretty well spelled out in a post I started about a month ago, basically the main weak points are thinner deck surfaces, thinner main webs, and less lifter valley cross braceing. On your 83 block will probably have less reinforcing ribs on the back just above the bellhousing as well. Do the search if you want to see a full blown debate over the power handling capabilities of the 4.1.

Just my $.01, my advise ain't worth anymore,

 

[NEARING]

Is there a "best year" for the 4.1?

Thanks