HP /HC oilpump-problems

[Dag-Henning]

I just found out (!) that my jackshaft has got its gear totally stript after abt. 50 min. of working....(!!!) Naturally, I suspect the HP/HC oilpump to be the reason for this . I run syntetic 0-40 Castrol RS, and do believe my warming up of the engine is good enough before pushing on. The gear on the oilpump looks to be hardened.......I can of course fit a bronze gear to the pump, but suspect I then will have to change it even more often that after 50 min. ....(??!) As it is a pain to take the pump out of a maximun lowered engine, I would try to avoid it.....
Any racers out there with similar experiences ??? Would I really need a HP/HC pump ?? ( The jackshaft is a std. item, no steel. )

Dag-H.

[lotusanglia1965]

I'm sure you only need bronze oil pump gear when using steel jackshaft.Read somewhere about drilling small oil feed to spray pump gear,though think this was for dry sump pump.I still think 0-40 is too thin for these old design engines.we use motorsport 15/w50 synthetic which is closer to the original grade.
sorry,haven't really helped,have I !!
Martin

[cabc26b]

Hi dag -

I have not seen the problem in my dry-sump race engine, nor did I see it in a modified ( 145hp) steet engine that ran wet sump . In the dysump motor I use Mobil 1 and the street was running a non-syn 20-50 . I have seen jackshaft failures on other engines though so , maybe since you need a new one anyways get a steel one and be done . Maybe somebody with more data point ( Rohan?) will see this and give us/you a more complete perspective .

[Dag-Henning]

Tks guys. Martin, I have considererd drilling this hole you mention from the HP port on the block-face onto the gear. I have also read somewhere that this is a must on drysumped engines, but not really nescessary with wet-sump.
Regarding the 0-40 Castrol RS, I have discussed racinglubs with the Castrol office, and were of the opinion, - initially-, that I needed something else. However, I have changed opinions......Provided your clearances are correct and your pressure is right, - i run at 60 psi -, the modern syntetic oils will offer more than the old mineral oils. They stand high temps better before breaking down, and they have a superior ability to hang /stick to the surfaces. ( not able to find the correct word..... ) However, this is a different discussion........oooops !
As the steel jackshaft no longer is available from people like QED, I think I will use a hardened and modified "std- item" , and maybe go for bronze gear on the pump......I will appreciate any thoughts and considerations from you guys, if you have inputs to give me !

Dag

[rgh0]

Dag

I have run both bronze and steel pump gears on both cast iron and steel jack shafts for High pressure / high volume pumps with no wear problems over lots of years.

Never run a 0W-40 oil as I go for a 50 hot rating. However I would not think the oil itself is the problem either as a good quality 40 rated synthetic probably gives a better hot performance than the orginal 50 rated mineral oils in real life. There should also be no problem with lubrication at the gear mesh point as lots of spray lube from engine oil flying around even in a dry sump motor.

The short life sounds like either a manufacturing problem or an alignment problem between the gears or a siezing problem in the pump itself. If the teeth are totally stripped off the pump gear then of the 3 options I would suspect a problem with the oil pump itself siezing when hot for some reason.


The Elan Factory in Australia can supply steel short jackshafts I believe if no one else still making them. I would install a new HP/HV pump (they come with a steel gear as standard) and new jack shaft, make sure everything is properly aligned and assembled and try again.

One tip with the HP/ HV pumps is to not instal them with the standard ford paper gasket but use a loctite rigid assembly sealant. if you use the paper gasket you will find the case cracks due to vibration and stress around the pump mounting bolt holes at above 7000rpm due to the heavier weight of the thicker steel end casing and the weight of an oil cooler sandwich plate if your using that also. If your not using above 7000 rpm then you dont need the HP / HV pump.

regards
Rohan

[Dag-Henning]

Thanks for your input Rohan. I do suspect a seizing problem within the pump itself.....Will dismantle and see...I am not impressed with the quality of the new pump compered with an old Ford/Burman-item. I will fit a new pump with a new steel jackshaft and follow yr advise regarding the gasket. As I run up to 8000rpm it will have to be the HP/HC then....
Will follow up on this thread after dismantling.....

Dag

[paros]

Dag
I use a QED hp/HV pump at an indicated 60 psi to nearly 70 when hot. However I don't necessarily believe the gauge so lets say around 60 psi at 7000. The oil is 20/50 synthetic [ Red Line ] and the jackshaft is a shortened normal cam and the pump, as I said is normal with no special gears.
Two seasons of racing 7500 and SO FAR no problems! Howver the quality of the latest pumps did not impress and I stripped one and did some selective assemly from an old pump.
I would guess, as you and Rohan have concluded, a fault with the pump is most probably the answer.
Being wet sumped [ baffled QED sump ]I also overfill the sump to help avoid starvation and suspect this makes a bit more splashing of the gears.
Richard

[Dag-Henning]

Thanks Richard, - seems that we need someone to produce better pumps.....- turning one of those pumps by hand tells me the tolerances may not be very accurate......I have ordered new pumps ( std.rate) from Ford, and will uprate them. If they seem superior in quality, I will throw the HP/HC pumps as far as I ever can. ( Believe Ford used the pumps until the mid nineties for Fiestas etc.....!)
Took me hours (!!)yesterday to pull the engine out, and I do not want to do that too often.....

Dag

[rgh0]

Dag

I looked at putting HP / HV internals into a standard ford casing after I cracked a couple of the HP / HV casings but found the bore and shaft diameters were slightly different on the pumps I compared. It could be made to work but in the end I stuck with buying new complete HP / HV pumps.

regards
Rohan

[Dag-Henning]

- Rohan, do you know if there are different suppliers / makes ?? If so, some might be better than others........

Dag

[cabc26b]

I heard about somthing called a "california wetsump" Not sure of the exact configuration but I want to say it uses a dry-sump pump with the stock oil pan and was intended to skirt the penalty assesed to elans that run a dry-sump here in NA . I don't know if the FIA will allow you run this but it is suppose to be pretty effective.

As i said before , I run the drysump and claim the car preped to 1966 specs- as we do not run to fia periods. My experiece here is that the organizers are very quick to move any lotus up a group regardless of the oiling system .... my next car ( 1964 S1) is intended to be acceptable anywhere in the world. so, I would like to keep in touch with this subject and any anything else having to do how best to build a "small valve" fia twimcam

[rgh0]

Dag

I have never done any research to try to idnetify if their are more than one make of HP / HV pump. I have source mine from the Elan Factory in the past. Given the relatively low world wide demand it would surprise me if more than one place was making them.

I was surprised by the shaft size differences as the HP / HV casting just looks like the orginal Ford casting with the Ford logo ground off. I can see no need for them to be different. May be it was just a tolerance thing and the set of HP / HV rotor shafts they got make tuned out a little wrong so they bored the casing a non standard size to suit.

I have heard of dry / wet sump arrangements. Basically you put a standard dry sump pan inside the original wet sump pan and use the orginal wet sump as the reservoir for the dry sump system. I guess it gets over surge problems and creates a little less oil drag on the crank while still sort of technically having a "wet sump". I dont think I would get away with it for to long in our historic class.

regards
Rohan

[Dag-Henning]

- no, that would definately be considered as an illegal twist of the rules.... I dismantled my HP/HC pump yesterday, and could unfortunately not find any obvious reasons for what happened......However, the pump-gear is "as new", and is quite clearly much tougher and harder than the jack-shaft. I guess my options would be one of either ; - fit a steel jackshaft and a new HP/HC pump, or fit a "std./modified/hardened" jackshaft and a std. pump with a HP-modification........
Have to sleep on it for a while.......
BTW, a friend from Sweden asked Tony Ingram (?) in the US abt. the matter, who also had thoughts abt. how the pump lined up and connected to the shaft-gear. Apparently, sometimes you need to modify the fitting-holes on the pump, and the hole in the block, to get the optimal clearences between the gears, - more or less as you would set up the diff.........
Life ain't easy........

Dag

[Dag-Henning]

- have done some further thinking in the matter, and found that my baffling is so effective (!)that it acts almost as a drysump.... - thus starving the jackshaft-gear of lubrication.......Have drilled a hole through the block where the oil leaves the pump and straight on to the gear, and will fit a brass insert with a 1,5 mm hole. That will at least assure me there is sufficient lubrication..!!

Dag

[rgh0]

Dag

While your baffling may be very effective and captures oil as effectively as a dry sump I dont think it ( or a dry sump) can adversly affect lubrication to the gear oil drive.

Most of the oil that goes through the pump comes out the main and big end bearings, much of the rest comes out the jack shaft bearings, much of the remainder that goes up to the head comes back down through the drain holes on the inlet side that drop straight onto the jack shaft. All of this combined with a turning crank and jack shaft ensure there is a constant spray of oil over everything inside the block. This spray lubricates the cylinder walls and pistons, the piston wrist pins and the exposed gears and chains and also helps with cooling the piston crowns.

While the bleed hole will not hurt I doubt that it does very much more in practice to aid the lubrication of the gear pump. I suspect its an old racers myth on its need in a dry sump engine. Someone a long time ago had a gear failure like you, probably due to a faulty gear or something similar, they put the lube hole in when they reassembled the engine and it worked next time so they concluded the lube hole fixed it. In reality it probably had no relationship.

regards
Rohan