Main Bearings

[dtpugh]

I suffered from zero oil pressure yesterday. :( The cause was a bolt coming out of the oil feed and the other was pretty loose. :mad:

I can see no bits in the oil, but thought as I have the sump off. I might as well check the main bearings?

Can the main bearing blocks be taken off (one at a time), to inspect the main bearing shells with crankshaft in situ?

If so and they need replacing, can the top shell be replaced by rotating? or is the only way they can be replaced is engine out and remove the crankshaft job?

Thanks
Dave

[mongoose]

The bearings can be replaced with the crank in situ,as you suggest,by rotating.This is how mine were changed on my old chim(serp 5 litre),just be sure to order the correct size,as there are several versions i think.Take one out and use the no.on the outer surface to identify.V8d were very helpfull with this when i had mine done,i recommend them if your wondering where to source.

[trackcar]

Ah so that was the cause then .. pretty common actually .. it's one of the things you check if you ever have the sump off to reseal it .. a dab of loctite would be a good idea when you refit

and just to add my for V8 dev too

[dtpugh]

Thanks for your replies, just wanted to make sure that I wasn't doing anything stupid.

However it certainly raised the question in my mind why there wasn't a spring washer on these bolts. If it comes off the gauze on the oil feed would stop it going into the engine. Or is there any other reason why these bolts do not have them? Seems like a bit of an oversight to me.

Dave

[boosted ls1]

Remove the caps one at a time and then use a blunt screwdriver to push the upper bearing round the crank. On the back will be the bearing size. Cross bolted engines have 2.500 crank journals, non cross bolted have 2.3" journals. I wouldn't remove all the caps at once though, I'd leave 2 in situ at all times to support the crank.

When you fit the sump it may be useful to glue the gasket to the pan using a hard setting sealant. Then use something softer on the block. Hope I've helped.

Boosted.

[dtpugh]

Thanks fingers crossed.

I am planing on having a look tomorrow evening.

Dave

[boosted ls1]

Quinny said:

Not quite correct boosted, I'm currently working on a 2.3" cross bolted block. Although not an original TVR block. The 2.3 crossbolted blocks are rare but they do exist Edited by Quinny on Sunday 4th September 23:05

I know about the motorsport X blocks but didn't think he's have one of those what with them being thin on the ground these days.

What's the history behind your block? Ex twr, Triumph?

Boosted.

[boosted ls1]

Course I asked, they're pretty rare. Do you go the Chesmans at all?

Boosted.

[boosted ls1]

Quinny said:

I'm sorry, Chesmans, I don't understand

I used to know an engine builder who I though may have been you but obviously not. He used to go to an engineering place called Chesmans.

Boosted.

[boosted ls1]

Well, hello anyway

[dtpugh]

Quinny said:

I bought it from V8D about 5 years ago as a 4.3BV to put into my old Griff 400 that had done well over 100k and the block had turned porous.

What do you mean by the block turned porous?

Dave

[boosted ls1]

dtpugh said:

Quinny said: I bought it from V8D about 5 years ago as a 4.3BV to put into my old Griff 400 that had done well over 100k and the block had turned porous. What do you mean by the block turned porous? Dave

Probably coolant leaking past the liners and either ending up in the sump or getting past the head gasket.

Boosted.

[Mutant Rat]

boosted ls1 said:

Quinny said: I'm sorry, Chesmans, I don't understand I used to know an engine builder who I though may have been you but obviously not. He used to go to an engineering place called Chesmans. Boosted.

Now there's a name from the past!

I used to use Chesmans way back in the old days for work on the Imp engines we used to fit in hydros!

The company is now better know for its work on Jaguar XK units, though they are highly regarded for all engine work.

Sadly, Andy Chesman himself was killed when he lost control of his boat during a race (in Germany? My memory fails me) a few years ago.

>> Edited by Mutant Rat on Tuesday 6th September 21:12

[dtpugh]

Ok understand now, I assume that this is through defects in the manufacturer of the block, which appear after running the engine for some time.

Dave