RE V8 starting up on 4 or so ...

I posted a query about my V8 always starting on significantly less than

8 cylinders a long while ago and got a suggestion about lifters and oil pressure.

Well, after extensive testing - ie starting it and watching the oil pressure gauge! - I can now categorically report that it is directly related to oil pressure - there is probably significant error in the gauge but as soon as it reaches at or around 20psi the thing takes off, every time. This would tally entirely with lifters pumping up as suggested. I'm not sure which sort I have fitted, perhaps lower leakage variety would solve the problem.

That's something for the future - it currently starts every time and it most definitely runs so I will not gut it's internals without due cause!

Reply to
AJG
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On or around Thu, 25 Dec 2003 21:32:48 +0000, AJG enlightened us thusly:

possibly a worn cam - if there's excessive clearance, and the lifters aren't pumped, maybe some valves don't open properly initially. it should fire on

8, and if you're listening closely, you can normally hear the valvegear quieten down once the oil pressure gets there.

If you have a good battery and a means of turning off the fuel, you could crank it for a bit before actually firing it, to give the oil pressure a head-start. In an ideal world, all engines would do this, as it's better for the whole thing not to fire instantly.

Reply to
Austin Shackles

In message , Austin Shackles writes

Shouldn't be - cam was replaced recently but I 'did a deal' with a vitesse block, a s/h 3.9 cam, the matching lifters, new push rods and timing gear ... there was no apparent wear in any parts when fitted ... the thing revs like stink now but has got bu**er all mid-range torque which I've got to work on ...

101s used to have the ignition system wired through the oil-pressure switch to achieve such a set-up. Slightly dicky battery, damp day, faulty switch or a multitude of other sins and the thing will kill the battery before it starts ...
Reply to
AJG

it was me that told you about the oil pressure and lifters . to cure inherent low oil pressure you could try fitting an oil pump booster plate kit. i think they are available from REALSTEEL in london, who do rover v-8 performance parts .

this is just a 2mm thick anodised aluminium plate that sandwiches between the oil pump body and engine block , it has slots cut in for various oilways .

it will restore a smooth face to mate to oil pump gears .

other than that take youre oil pump off and get the face of it lapped off again , you probably have some nice grooves in the face of oil pump body which are making the oil pressure drop .

if you fit the plate kit to the oil pump make sure its correct kit , some you have to put extra hole in if its used on SD1 type pumps .

there is also an oil pressure relief spring in the pump, this may have got soft , there are various springs available according to what pressure you want to run it on .

good luck .

Reply to
M0bcg

I though that the 101 should just have the fuel pump 12V feed switched, not any of the ignition system. My 101 definately only had the fuel pump switched, as it now goes though a manual switch. You could do this to give it an opportunity to turn over a few times before you start it.

Reply to
Tom Woods

On or around Fri, 26 Dec 2003 17:34:02 +0000, AJG enlightened us thusly:

odd. dunno then. what oil are you using?

Reply to
Austin Shackles

In message , M0bcg writes

Already got a high volume pump conversion on it - when it's idling it sits at about 50psi ... for a V8 that's miraculous! My conversion came from Rimmers but is probably the same part.

It has to be the lifters simply because I do get good oil pressure but, as with everything, it just takes a few turns to do whatever the oil needs to do - lifter pump up being the only obvious one. The best solution may be to try another set of lifters and see if they suffer from the same bleed down characteristics but, as I said, I'm not really in the mood for that.

Reply to
AJG

Would you perchance have fitted a non-standard cam, and the lifters have a higher rate 'bleed down' to compensate for running a lower compression ratio than the cam profile indicates (so you get your vacuum back and better low down torque)?

Otherwise if its a standard cam and lifters, then some are dodgy! Beth

Reply to
Beth Clarke

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