Rover V8 rebuild crank problem!!

Sammy · Post by **Sammy** » Tue Feb 18, 2014 9:54 pm

I'm starting the rebuild, and everything seemed to be going ok... I've got a reconditioned crank, new shells, arp studs. I fitted the crank dry with plastigage and the clearance is ok (all around 0.050mm).
I've now put assembly lube on the shells and the journals, and evenly torqued up caps 1-4 first as per the Haynes manual (think I did all 5 caps when I did it dry).
Crank rotates OK, but now I've fitted rear cap 5 the crank is locked solid. If I loosen cap 5 it will rotate again, but as soon as it gets as little as 20ft lb it locks the crank.

I suppose I'll have to pull it all apart, check it all out and start again. Any ideas what it could be?

I torqued up caps 1-4 to 60ft lb (didn't feel comfortable going higher despite the arp figure of 110ft lb).

Thanks!

unstable load · Post by **unstable load** » Wed Feb 19, 2014 5:11 am

Did you index the main caps before you stripped the engine? In other words, is the cap on the same way around or is it only able to fit one way?

DEVONMAN · Post by **DEVONMAN** » Wed Feb 19, 2014 8:23 am

Is it a cross bolted type block?

Try rotating the crank with just cap no 5 bolted up.

DaviesDJ · Post by **DaviesDJ** » Wed Feb 19, 2014 9:09 am

If the crank has been heat treated it my no longer be straight, this can be fixed, if the block was fine before then it is likely to be still fine. But as states if they are the wrong way round etc this can be the problem. If it is a different block or it has bee overheated etc it may be warped and need line honing.

Sammy · Post by **Sammy** » Wed Feb 19, 2014 6:47 pm

Doh!

The rear cap only goes on one way, and has two large rubber cruciform seals which go on each side of the cap. These seals are a tight fit, and when I've pressed the cap into place a small piece of the seal broke off and landed on the journal. So it got compressed and has made a nice little dent (about 3mm diameter) in the shell on the cap.

The cap now goes on properly without locking up the crank, I just have to decide whether or not I need to replace the dam shell?

DaviesDJ · Post by **DaviesDJ** » Wed Feb 19, 2014 7:50 pm

Great! Glad you found that- I would replace it for the sake of a shell! You will only worry about it - and she'll problems can lead to crank problems Etc. if there is a dent in it then that may cause poor contact and a drop in oil pressure etc

Sammy · Post by **Sammy** » Wed Feb 19, 2014 7:59 pm

Yes, I've just ordered another bearing set and cruciform seals.
I just hope it gets here for the weekend!

Cheers