EA71 Out of Round main bearing supports

[howpow]

Hi folks, My EA71 crankcase Main Bearings supports are now out of round, and the engine knocks really badly until the oil circulates. I Have another engine which has the same problem. I have heard that you can shave the mating surfaces of the crankcase and then have it linebored, or apparently some cars such as VW's and Porsches have external oversize main bearings shells available which still requires a linebore but eliminates any other problems.

What have the experts here done in this situation. :-\

Thanks

Edited December 16, 2010 by howpow

[howpow]

Bump. Am I the only person who has had to tackle this problem.

[subaru360]

You would have to surface the case halves then linebore the block. Be sure to verify piston to head and piston valve clearance afterwards if a lot is taken off. This will also raise the compression slightly, probably not enough to matter.

 

Probably cheaper in the long run to get another block, ea71s are cheap enough.

[Datsunrides]

I would agree that it would be better to get a good replacement engine than try and save the old one. Probably cheaper too. I would think the traditional method of line boring would create a whole lot of other issues, like line boring the cam supports also, possibly having to shorten the pushrods, etc. I believe you can get oversized (thicker) bearing shells, that are meant to be used in a bored out (not line bored, two different things) block. Again, I would just go with a new motor. I still see old stock rebuilt EA71's popping up now and again for less than $500, sometimes much less.

 

Mark

[howpow]

Thanks for the replies guys. EA71's are pretty rare these days in Australia. I will see if I can track down the thicker shells if available, that sounds like a good option.

Thanks again.

[Datsunrides]

May be better to upgrade to an EJ.

 

Mark

[GTlegs]

Thanks for the replies guys. EA71's are pretty rare these days in Australia. I will see if I can track down the thicker shells if available, that sounds like a good option.

Thanks again.

 

Mate, give Duggan balancing in Reservoir a call. They did all the machining and blue printing work on my Chrysler 360 and know what they are doing. They have a good reputation in chrysler and ford circles.

 

Really nice blokes there too - dont just dismiss you and explain everything. Dont know how much they will knwo about subaru engines, but worth a shot.

 

Otherwise how do you know its actually out of round and not something else?

 

Also, have you thought of dropping an EA81 in it? As you know I have a 77 GL, and I have an EA81 sitting at the back. I will see if its a straight drop in this xmas break and can let you know.

 

Youre in Cheltenham arent you? Let me know if you need a hand.

[idosubaru]

sure the blocks are toast? maybe it's something else?

 

if engines are hard to find i'd see if you expand available motors - are EA61, EA81, EA82's easily bolted in place as well?

[howpow]

Hi GTlegs. Yes I am in Cheltenham and thanks for the offer. I'm 68 and have a best mate who I have known for 60 years. We are both retired so we alternate every Monday. One Monday we work on his cars and next Monday on mine, so I'm OK for help, but if we need someone fit, young & flexible I'll let you know. I'll have a word to Duggans and see what they can suggest.

Grossgary, I'd like to stick with the EA71 because it's a bit special. It has ported and modified EA63 GSR heads and camshaft, hand fabricated SS extractor system and twin choke downdraft Weber.

I think the heads are part of the problem as even thought the combustion chambers were opened up a bit my compression guage was showing about 195 psi per cylinder which I think put a bit too much strain on the main bearings. I've had VW Beetles in the past and they were known for ending up with oval main bearing supports if the engines were lugged at low revs, this sounds just the same, very heavy knocking until the oil circulates. With the VW's and Porsches you can get thicker main bearing shells and have the crankcase halves machined to suit. This would be my best option I just have to find out if they are available or not. Failing that I might have to go the skim the crankcase face route with all it's complexities.

[GTlegs]

Hi GTlegs. Yes I am in Cheltenham and thanks for the offer. I'm 68 and have a best mate who I have known for 60 years. We are both retired so we alternate every Monday. One Monday we work on his cars and next Monday on mine, so I'm OK for help, but if we need someone fit, young & flexible I'll let you know. I'll have a word to Duggans and see what they can suggest.

Grossgary, I'd like to stick with the EA71 because it's a bit special. It has ported and modified EA63 GSR heads and camshaft, hand fabricated SS extractor system and twin choke downdraft Weber.

I think the heads are part of the problem as even thought the combustion chambers were opened up a bit my compression guage was showing about 195 psi per cylinder which I think put a bit too much strain on the main bearings. I've had VW Beetles in the past and they were known for ending up with oval main bearing supports if the engines were lugged at low revs, this sounds just the same, very heavy knocking until the oil circulates. With the VW's and Porsches you can get thicker main bearing shells and have the crankcase halves machined to suit. This would be my best option I just have to find out if they are available or not. Failing that I might have to go the skim the crankcase face route with all it's complexities.

 

Sounds like you have a decent idea re the noise, but are you certain its not just a spun bearing? These make a weird knocking noise too.

[idosubaru]

are you certain its not just a spun bearing? These make a weird knocking noise too.

that's the usual lower end failure mode. there's a couple folks on here that have seen a lot of this that could comment, maybe they'll show up. if you're just guessing on the out of round stuff then it's probably likely that won't be the case and a standard rebuild will suffice.

[howpow]

Hello again GTlegs. We actaully lifted the motor out today and have started to strip it down. Once it's all apart I'll get it measured up and see if that is the problem. Thanks for your interest.

[howpow]

Hi grossgary, I hope you're right, that would be an excellent outcome.

[NorthWet]

Responding to your post in a different thread regarding oversize bearings:

 

I currently do not know where to get oversize bearing shells, though I have heard of them for other vehicles in the past. I would suggest that you start a thread specifically asking about oversized bearing shells, and/or contact people that are more likely to know or at least know where to look, (Moosens, General Disorder, ShawnW, Qman and Mcbrat come quickly to mind.) Emily at CCR (vendor of rebuilt Subaru engines and other goodies) might also be a resource.

 

Frankly, I m with GG on this. I have not heard of any of the EA engines messing up there bearing saddles enough to be mentioned. Think good thoughts, take it apart and look over and measure things. I think that you will be favorably surprised.

[Ross]

Oversize bearings shouldn't be hard to get, any parts store should do them -- this was the case when I rebuilt my old ea81 anyway...

[howpow]

Hi NorthWet. Thanks for your response. I'll be pulling the engine apart once the Christmas break is over and I'll have it measured then so here's hoping.

Ross the bearings I was refering to are not normal oversize bearings used when the crank is reground, these are a thicker shell bearing to allow the crancase to be machined to solve any distortion problems.

[ShawnW]

If anything is wrong with the main bearings its likely the thrust is shot so the crank is moving too much front to back not side to side.

 

I haven't ever seen an ea81 or ea71 that needed line bored. Frankly they toss rod thru top of block or some other catastrophic failure before the roundness really becomes a problem. If I found one that way I would scrap it and move on to another one.

 

Putting an ea81 in the car isn't as easy as it might look. It would probably be easier to get custom rods and pistons and change the stroke of the engine if you really had to have .2L more displacement.

[swampbrat]

Indeed , the bolt patern on an ea71 is the same shape as an ea81 , but about an inch smaller. If we were not on opposite ends of the planet , a friend of mine has a built EA71 with a tuned turbo sitting on his shelf. ( he lost his health license and no longer builds or flies helicopters ).