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 Posted: 07-07-2016 01:24 am
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scottsmi
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I have a freshly rebuilt 1973 mark 1 and upon starting it for the first time it has oil pressure at 100 pounds. I checked the pressure with an oil pressure tester and it is really at 100 pounds. I removed the oil pump to inspect the relief valve and it does move but I cant tell if it is really working. Do these things go bad or does anybody have any other ideas? I use 20/50 oil per the specs.

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 Posted: 07-07-2016 05:08 pm
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Greg Fletcher
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If the oil pump relief valve has something sticking in it causing the spring to bind, you will see the opposite (assuming all other things are working as intended) as very low or almost no oil pressure.

Higher oil pressure is normal if the engine was rebuilt correctly, that is; the main bearing are within spec and inner and outer oil pump rotors are brand new. These two things have the biggest impact on the oil pressure from what I have seen. My engine (with a couple thousand miles on it) shows about 90 lbs on the gauge when cold and with the engine warmed up and at cruising speed will show about 50+ lbs. Have you driven the car? What is it showing while you're driving it?

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 Posted: 07-07-2016 09:26 pm
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subwoofer
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A 5w-40 oil should be more than thick enough, and will greatly reduce wear when cold (which amounts to at least 90% of total wear. Ditch the Stone Age oil!

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 Posted: 07-08-2016 12:52 am
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scottsmi
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Thanks Greg, I haven't driven the car yet because of the high pressure. Since the gauge only goes to 100 the pressure pegged the gauge and broke it (the needle went back in the gauge where you cant see it) so I didn't warm it all the way up. All of the bearings were plastic gauged and were well within tolerances. Crank turned ect. I had read several posts about rebuilding the relief valve and thought that may have some impact. I have also read that it could be a blocked oil galley. I didn't put it together at the time but earlier (a few months ago) I tried to start it and the oil filter blew off. I thought I had not tightened it during installation but now I'm not sure.

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 Posted: 07-11-2016 07:35 pm
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Greg Fletcher
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Lots I don't know, but I would also look toward a blocked oil gallery at this point as that sounds like some very serious pressure building up. Be sure you use a good quality oil filter too, such as a K&N. An oil filter with a malfunctioning by-pass valve can cause all kinds of problems. I would start with the easiest thing first, the oil filter and then remove the oil pump housing and carefully go through it to see if anything is amiss.

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 Posted: 07-12-2016 03:00 am
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scottsmi
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Thanks Greg. I broke down the oil pump and I think the plunger is in backwards from the machine shop. This is how I pulled it from the housing.

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 Posted: 07-12-2016 03:04 am
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scottsmi
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This is how it looked.

Attachment: IMG_0975 (3).JPG (Downloaded 195 times)

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 Posted: 07-12-2016 03:05 am
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scottsmi
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shop photo

Attachment: IMG_0976 (2).JPG (Downloaded 194 times)

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 Posted: 07-17-2016 02:57 am
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scottsmi
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Update on oil pressure. After turning the plunger around and reinstalling pump pressure now reads 60 pounds at start up.

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 Posted: 07-31-2016 02:41 pm
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redracer
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Yes, looks like someone put in backwards. I would shim the spring with small flat washers in the back of the retaining cap; be sure it is less than 6mm with all the washers or the valve will not open enough to bypass the oil, causing the oil filter to "balloon" with higher rpms.

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 Posted: 08-01-2016 01:23 am
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Esprit2
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907 Oil Pressure Specs

Jensen-Healey at normal operating temp (hot)
60 psi (4.2 kg/ sq cm) at 2500 rpm

J-H's 60 psi oil pressure spec is possible, but not normal, especially if the engine is now old with a lot of miles on the clock. Looking for 60 psi will result in a lot of un-necessary disappointment.

Lotus at normal operating temp (hot)
Not below 5 psi (0.35 kg/sq cm) at idle
Not below 35 psi (2.5 kg/ sq cm) at 3500 rpm
Not below 45 psi (3.5 kg/ sq cm) at 6500 rpm

Lotus' specified minimum oil pressure at idle scares me. No 'healthy' 907 will have oil pressure that low, and 5 psi at hot idle clearly indicates something isn't right.

All Lotus engines prior to the current Toyota powered cars use main and rod bearings with rather wide tolerances. The design depends upon a high viscosity oil (20W50 / 10W60) and an oil pump that can deliver a large flow volume at a modest pressure. High pressure is not a design parameter, and it is not necessary to shim the relief valve's spring to achieve 60 psi at 2500 rpm.

Modern engines must meet mandated efficiency standards, so they're using thinner oils... like 0W20 to 5W30. Those thin oils require much tighter bearing clearances, and higher oil pressures. Just because some modern, thin oil works great in your new daily driver doesn't mean it will work great in your 907. It won't!

Keep the viscosity up, and hot oil pressure of 35 psi is reasonable on the street, maybe 45 psi on the highway, and 50+ on cold start-up. 60 psi hot is not necessary, or even good.

Regards,
Tim Engel

Last edited on 08-01-2016 01:27 am by Esprit2

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 Posted: 06-13-2017 06:51 pm
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Spaceman
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I have the same problem, oil pressure too high, so looking at the picture, which one is the valve? Appears to me its the little cylinder with the holes, and the other end with the o-ring is a retainer.

Also, I have successfully repaired my oil gauge which also bent past 100, seems if they go too far, a little wire pops out of the needle. All you need to do is pull the bazel, undo the nut on the back, and reposition the wire back in the needle. The bladder doesn't appear bent too much.

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 Posted: 06-15-2017 12:12 am
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Esprit2
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Please excuse the redundancy, but I just posted this photo in another thread on this same general subject. All the parts together make the pressure relief valve. These parts are typical of the Lotus and Mk II JH oil pumps, while the Mk I JH has a different piston config. Look past the details, and both versions work basically the same way.

At the far left is the 'Insert'. It's just a hollow sleeve that serves as a spacer for the black 'Sleeve'. The longer the Insert, the higher the Sleeve and it's ports, and the higher the vent pressure.

Second from the left is the 'Piston'. It's a hollow cup, open to the left in the photo. It's closed end on the right also has a tapered, or domed end. The closed end must face the pump's rotor & annulus. The open end faces right in the photo, and the coil spring slips into it.

Third from the left is the black 'Sleeve'... ie, the cylinder. It has ports, or open holes through it's wall. As the piston moves right through the cylinder, it eventually uncovers the ports, venting some oil and relieving the pressure.

Fourth from the left is the coil 'Spring'. It slips into the cupped piston on one side, passes through the sleeve, and slips into the cupped cap on the other side. It's length and spring rate are fixed and not adjustable, but some people have been known to shim it with a washer or coin in order to increase oil pressure. Springs can fatigue with age and become weak. When that happens, the relief valve will vent early, and the oil pressure will be low.

Finally, on the far right, is the 'Cap' and it's rubber O-ring. It's a press fit into the pump housing. The Cap contacts the end of the Sleeve, pinching it securely between itself and the Insert at the far end of the bore. The length of the Insert therefore positions the Sleeve, and there for the ports; and that determines when the piston uncovers the ports to vent oil.

If the piston is installed backwards the vent pressure will be high. The coil spring will contact the piston's closed end, instead of slipping into the piston. That means the spring will be compressed more, resulting in higher pressure. Also, the piston's tapered/ domed end will be replaced by it's square end. That means it's edge will reach the ports later, also resulting in higher vent oil pressure.

Good luck,
Tim Engel

Attachment: 9XX Lubrication - Oil Pressure Regulator 06.jpg (Downloaded 91 times)

Last edited on 06-15-2017 07:59 pm by Esprit2

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 Posted: 06-16-2017 02:23 am
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scottsmi
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Thanks Tim,
That was a great narrative and exactly right from my experience. After taking apart the valve and studying the parts catalog and reversing the piston it fixed the too high pressure problem. My pressure is now approx 50lbs at high idle up to 4000 RPM and 35lbs at idle. I since have developed a small leak that may be coming from the filter attachment point (new filter as well). Its not bad but annoying. I did replace all of the seals during the rebuild. Not a big fan of the "doughnut setup" for the oil cooler lines. I wish there was a better setup to achieve a better seal.

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 Posted: 06-16-2017 06:10 am
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Esprit2
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Did you replace the seal between the oil cooler sandwich plate and the auxiliary housing? It tends to get over-looked.

Regards,
Tim Engel

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 Posted: 06-16-2017 01:40 pm
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Brett Gibson JH5 20497
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That seal between the oil filter plate and pump can be purchased at Delta, or you can get the exact same square cut O-Ring from a Fram Oil Filter # PH3682 for 1/2 the price. I have used them for years with no issues.
Brett

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 Posted: 06-17-2017 02:51 pm
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scottsmi
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I did replace the seals (back and front) of the "doughnut" during the rebuild and inspected them again recently do to the high pressure situation and they seemed fine. But maybe something got warped during the process? I would really like to put a remote filter system in to make the system easier to work with. I have seen it on some JH's, Is there a kit available?

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 Posted: 06-17-2017 02:53 pm
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scottsmi
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Do you just buy a filter and pull off the ring? Also is this right fram filter for the JH? I use the K&N but it is expensive and large in size and can make it hard to get to other parts.

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 Posted: 06-18-2017 03:07 pm
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Brett Gibson JH5 20497
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The Fram filter does not fit a JH, It's a Nissan Maxima filter which at one time I happened to own, some how I ended up comparing that square cut O-ring to the JH fitting and it was a perfect match, so have been using it ever since, and so have a few other JH owners with no complaints over the years.

my oil filter list for a JH shows: Fram PH16 / Purolator L14670 & K&N HP 2004. But I like to stick with the K&N, I have cut all 3 up and by far the K&N is the better quality one.

Brett

Last edited on 06-18-2017 03:09 pm by Brett Gibson JH5 20497

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 Posted: 06-19-2017 04:47 am
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Esprit2
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The following is probably more than you want to know, but...

Over the years, Lotus had three oil filters for the 9XX 4-cylinder. All had the same basic part number, but with A, B & C prefixes. The early A907E6000 filter was introduced with the 907, and used on the 912 and early 910 Turbo.

The Bosch injected 910 had unique filter needs, and the B907E6000 filter was introduced for it. The B-filter will not adequately engage the threaded spigot on an earlier 9XX engine (907), and may come loose. Never use a B-filter or an equivalent cross-ref filter on a pre-1986 9XX, including the 907.

Finally, Lotus introduced the universal C907E6000 filter that is compatible will all 9XX engines, from the 907 through the 1996 910S. That's all that is available from Lotus now... the A & B prefix filters have been discontinued.

Why does a JH owner care? Maybe you don't. But if you're looking for aftermarket cross-ref filters, there are lengthy lists in the Lotus community. You can use any of the A & C equivalents, but do not consider a B-equivalent cross-ref. Websites should just purge all B-prefix references, but the fact is that they're still out there. If you're shopping Lotus sites for 907 filter recommendations, know what the person is recommending the filter for. If he owns a 1986-88 Bosch injected Esprit, do NOT follow his lead without asking which prefix letter it's equivalent to.

A-Prefix alternatives: (Pre - 1986 9XX cars)
Chrysler............ 2.2 4-Cylinder
Ford V8 ............ 289/ 302/ 351 Windsor
Ford V6 ............ 2.8 (USA models, Mustang II etc)
Ford L4 ............ 1.6 / 2.0 / 2.3 (USA applications)
Ford / FoMoCo ... DIRY-6731A
MG.................... MGB / MGB-GT
SAAB................. 99 / 900 / 9000
Volvo ................ All Volvo gas engines (except 850?)
AC Delco............ PF-13* PF-20
Champion........... PH-228
Lee.................... LF-17HP LF-16 LF-16HP
Motorcraft .......... FL-300
Purolator ........... L10017* PER 17(old) PER-8100
Purolator............ L102421

FRAM filters are not the most highly regarded amongst Lotus owners, so use them at your own discretion... but here they are:
Fram ExtendGuard .. XG43 (modern line extension)
Fram X2 ................. XG43 Esprit / Elite / Eclat (name before ExtendGuard)
Fram ToughGuard .... TG43 Esprit / Elite / Eclat
Fram High Mileage ... HM43 (modern line extension)
Fram DoubleGuard ... DG43 Esprit / Elite / Eclat
Fram....................... PH-16, PH-3963, PH-43*
Fram ExtraGuard ..... PH43* Esprit / Elite / Eclat
Fram ExtraGuard ..... CH820PL 1973-74 Elite listing

*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*

C-Prefix alternatives: (1989-Onward 9XX cars)
Coopers/Fiaam ......... FT4883
Baldwin ................... B163
K&N ........................ HP-2004 (K&N 2004) (It's a tight fit / made by Champion Labs)
Lucas ...................... F5534 (Tingles supplied for all 9XX)
Mann........................ W712/38
Mobil-1 .................... M1-204 (made by Champion Labs)
Purolator Pure-One.... PL20081 (3.77 OD x 3.75 Length – 8-16 psi Pressure Relief Valve)
Volvo OEM filter ....... 1950-present Volvo "gas" engines (except the 850)
............................... Good quality, proper anti-drainback valve, and aren't expensive.

**K&N oil filters have a 1 inch nut on the end to aid in removal. But that makes the filter longer and a difficult fit in some Lotus applications.

*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*

In general, the more expensive filters have better filtration. Even if two different filters look identical on the outside, they very well may have different filtration media inside them. In broad strokes, there are really 4 quality levels of filters:

Dealer/Lube Shop Brands - Pennzoil, Valvoline, Quaker State
- These are generally lowest quality, capturing 40 micron sized particles.

Conventional
- Fram Extraguard, Purolator, ACDelco Duraguard, Wix
- These are around 25 micron filters.

Mid-grade
- PureOne, Fram Toughguard, AC Delco Duraguard Silver
- These are generally 10-20 micron filters.

Premium
- ACDelco Ultraguard Gold, 8-10microns,
- Mobil One, 10-12 microns.

*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*

A fellow on the Turbo Esprit list used a Ford 90 Degree adapter from a 1994 4.0L V-6 SUV engine (also Ford Ranger). Adapters can be found in the $20 to $40 range on e-Bay or junk yards, or new from Ford parts. This turns the filter to a vertical position, hanging down. It's more easily accessible from below, and it doesn't spill oil when it's removed.

Cast in markings:
Ford
C9J1A
89TM6884AA

Some adapters have different casting numbers, so make sure it’s the one with INCH filter threads! (3/4"-16) If buying used, look for one that is complete with the special mounting bolt.

While at it, he also installed a Mocal Oil Cooler adapter with built in thermostat for faster warm-ups. He machined off the OD threaded portion on the Mocal adapter bolt and re-cut the thread all the way through.

If the factory oil cooler sandwich plate is retained, then a simple threaded adapter can be made. This adapter needs to be a little shorter to ensure full compression of both sandwich plate and adapter O-rings.

Use Permatex 56521 - High Performance Thread Sealant to seal/lock the adapter the same way the Lotus factory sealed the thread extension adapter (which, by the way, needs to be removed in order to mount the new threaded adapter piece).

If interested, I have a Word.doc article, complete with photos.

Regards,
Tim Engel

Last edited on 06-19-2017 05:02 am by Esprit2

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