Matt306 Posted April 18, 2017 Share Posted April 18, 2017 I never worked much on the engine, but now have an mot might start fiddling to eek out a few more BHP. I have noticed when hot the oil pressure at idle is low. I never disturbed the oil pump so might look at swapping this out. As some holiday reading http://www.totallytriumph.net/spitfire/engine_building.shtml this suggested you could use a 1500 spit oil pump on earlier engines. I am thinking this would apply to herald 1300 engines pluses seem to be price, any reason not to?I am using Halfords standard historic 20/50 oil.I know oil pressure won't help BHP, however to low oil pressure will ensure no BHP. Quote Link to comment Share on other sites More sharing options...
rustbuckit2011 Posted April 18, 2017 Share Posted April 18, 2017 Yeah do it. Its easier to find and the same pump used on the 6 and apparently ford pintos. Should be ample for the 1300. Its a direct swap, no modification necessary. Having said that, I dont think there is anything wrong with the oe pump fitted to standard engines up to spitfire spec- they just require their tolerances checked and flat surfaces lapped. Quote Link to comment Share on other sites More sharing options...
Clive Posted April 18, 2017 Share Posted April 18, 2017 The most leikely cause of low oil pressure is worn crank bearings.However, if you intend to have the sump off anyway, it is little extra work to drop the big end caps and inspect the bearings. A change to new ones will improve things hugely. SWapping the main bearings is a little trickier, but again possible in situ, and while you are there do teh thrusts too.....Likely your pump is better than any of the new ones available.......Also, check the pressure relief valve is shutting totally, maybe a new spring for that? and check the surface to make sure it is undamaged. Quote Link to comment Share on other sites More sharing options...
Steve P Posted April 18, 2017 Share Posted April 18, 2017 I got better pressure, especially when hot using a decent oil.I always use Valvoline VR1 in mine.Steve Quote Link to comment Share on other sites More sharing options...
Matt306 Posted April 18, 2017 Author Share Posted April 18, 2017 Quoted from cliftyhanger The most leikely cause of low oil pressure is worn crank bearings.However, if you intend to have the sump off anyway, it is little extra work to drop the big end caps and inspect the bearings. A change to new ones will improve things hugely. SWapping the main bearings is a little trickier, but again possible in situ, and while you are there do teh thrusts too.....Likely your pump is better than any of the new ones available.......Also, check the pressure relief valve is shutting totally, maybe a new spring for that? and check the surface to make sure it is undamaged. When I did the car the engine had minimal work as it ran. I did take the head off and put in new valves guides and skimmed the head. Worn rocker gear was replaced too. New core plugs and seals all round. The sump was taken off but didn't touch oil pump. Since then we have completed RBRR. Engine bearings haven't been looked at all. Canleys standard size bearings make it a no brainer to change. Quote Link to comment Share on other sites More sharing options...
Clive Posted April 18, 2017 Share Posted April 18, 2017 Do check the bearings for size. It is very possible the crank has already had a regrind, and yiou won't know until you take the bearings out.And pay the few pounds extra for the HD or LC bearings, they should last better. Quote Link to comment Share on other sites More sharing options...
Matt306 Posted April 18, 2017 Author Share Posted April 18, 2017 Simpleton question HD/LC? Quote Link to comment Share on other sites More sharing options...
Clive Posted April 18, 2017 Share Posted April 18, 2017 Sorry. HD-heavy duty. LC lead copper.The "better" bearings are marked as such.Ideally a set of vandervell, but they are rocking horse poo these days, County/King bearings are about the only easy to find ones. Quote Link to comment Share on other sites More sharing options...
Matt306 Posted April 18, 2017 Author Share Posted April 18, 2017 Candles sell LC bearings so ill go for them Quote Link to comment Share on other sites More sharing options...
Matt306 Posted April 19, 2017 Author Share Posted April 19, 2017 I take it the only way i'll know if the bearings are oversize is to take em out? Are they marked oversized or is it measure the bearing or shaft Quote Link to comment Share on other sites More sharing options...
JumpingFrog Posted April 19, 2017 Share Posted April 19, 2017 Quoted from Matt306 I take it the only way i'll know if the bearings are oversize is to take em out? Are they marked oversized or is it measure the bearing or shaft You have to take them out unfortunately. They will be marked on the backs. Something like "010" would be 10 thou undersize. There should be nothing other than a part number and manufacturers name/mark if they are standard size.One thing worth adding is that the Spitfire oil pump may need to be slightly modified to fit, I'm current rebuilding a 1296cc engine and have a Spit 1500 oil pump to go in. However, when I test fitted it I could get a 10 thou feel gauge under the rear of the pump (which wouldn't be ideal for oil pressure). I think I'll have to fettle the casing of the pump (it contacts the side of the block) with a file to allow it to sit flush. Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted April 19, 2017 Share Posted April 19, 2017 Check the clearances on the new pump carefully. They may not be better than your old one!The aluminium bodied 1500 pump is higher capacity than the early iron bodied pumps, but the alloy body means the end float on the gears increases more with temperature so they don't always give better hot idle oil pressure. It is not the same as the 6 cylinder pump and not the same as the Ford pinto pump (well, possibly the gears are same as pinto ones but the rest certainly isn't). They also turn up with strange pick-up pipes sometimes (Dolly? Midget?) and if your engine is early enough to have a strainer gauze across the top of the sump you'll have to find a way around that. May be possible to use the end cover from the original pump after lapping out any scratching/scoring on it's working surface but do check that the port lines up properly.JF's point above is well made - also check the outlet port lines up properly with the oilway in the block.As already said, bearings will be marked with 010, 020 or whatever if the crank has been ground. Usually the big ends will be showing some copper as will the bottom of the centre main and the bottom of the rear main. The front main is usually better and if the rear main shows no or very little copper I've been known to leave the front alone to avoid disturbing the bridge-piece and gaskets at the front. If none of them shows any copper, either they've been changed quite recently or they are aluminium tin bearings.....Don't forget the thrust washers on the rear main.Nick Quote Link to comment Share on other sites More sharing options...
Matt306 Posted April 23, 2017 Author Share Posted April 23, 2017 On my Oil pressure guage, I have the following readingsCold idle around 50 PSIHot Idle around 5-10 PSIHot 3000 RPM (drive) 30-40 PSIHot 4000 RPM (Revving) 50 PSIAny thoughts before the sump comes off. Quote Link to comment Share on other sites More sharing options...
daver clasper Posted April 23, 2017 Share Posted April 23, 2017 There is a factory figure for oil pressure (for example the 2 litre 6 cylinder is between 40-60 at 2000 rpm , toward the higher end better). None given for idle, though I think 20+ is considerd ok.Dave Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted April 23, 2017 Share Posted April 23, 2017 On the low side but not awful.A set of shells could well bump those up 10 - 15psi on their own.NickQuoted from Matt306 On my Oil pressure guage, I have the following readingsCold idle around 50 PSIHot Idle around 5-10 PSIHot 3000 RPM (drive) 30-40 PSIHot 4000 RPM (Revving) 50 PSIAny thoughts before the sump comes off. Quote Link to comment Share on other sites More sharing options...
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