Sprint Bottom end rebuild - can it be done in the car?

[Bluevitesse]

Hi all

I tried to search for "big ends" but can't seem to stop it searching for either "big" or "end" which gives me hours of entertainment paging through irrelevent posts.

Anyway.......The oil pressure on my Sprint is suspect. The voltmeter has been replaced with an oil pressue gauge which was sticking at 15psi when I bought the car. I replaced the gauge with another of unknown accuracy and this one reads double that but is still worryingly low. There are no untoward noises and I will put the gauge out of my Vitesse in it to confirm before going any further but in anticipation of surgery being on the cards...........

I know the sump comes off with the engine in the car and presumably it's not too difficult to replace the big ends assuming a re-grind isn't in order. But can the mains be changed in situ too?

Cheers

Glen.

[xvivalve]

Glen, if you are getting 30 psi at warm idle on a standard engine, I wouldn't be worrying too much. Does it rise readily with increased rpm?

Trying to replace the mains with crank in situ would involve dubious methods such as 'pushing a half shell in with a feeler gauge'; if there is effectively little wrong with the engine as is, you could end up messing with it and making matters worse.

[tony g]

A trick ive used for years to get the mains from the block side:
Get a flat headed nail like the ones for felt roof etc, put it in the ctank oil hole and rotate the crank. It just pushes it out,

Tony

[Bluevitesse]

Glen, if you are getting 30 psi at warm idle on a standard engine, I wouldn't be worrying too much. Does it rise readily with increased rpm?

Trying to replace the mains with crank in situ would involve dubious methods such as 'pushing a half shell in with a feeler gauge'; if there is effectively little wrong with the engine as is, you could end up messing with it and making matters worse.

Hi

It sits at 30 psi pretty much irrespective of engine speed, it's probably lower at hot idle but I haven't had the opportunity to get it really hot yet. It also takes a while to come off the stop on start up though the dash light goes out immediately. This is why I need to fit a known good (From my Vitesse) gauge before delving deeper. The slow responce from startup could just be air getting compressed in the line.

I'm not afraid of "dubious" methods such as the one suggested above if it saves me a lot of pain but will be carefull not to cause more damage than I'm curing. Mind you laying on my back being dripped on is not pain free...........so maybe I will whip the lump out anyway if it comes to it.

Glen.

[GrahamFountain]

with the engine in the car... replace the big ends assuming a re-grind isn't in order

I've had this done twice now, i.e. replace the ends and mains without regrinding the crank, both times as part of replacing one or more pistons because the lands failed through pinking. In neither case was there any suggestion that the bearings were actually in need of replacing. It was just done because they were out, and could be replaced.

Both times one of them failed within a couple of hundred miles.

I've since been told that this is common, and it would have been fine if the olduns had gone back in where they'd come from, but I've no proper explanation of the cause.

Graham