Jupiter restorations.

[Forumadmin]

Suggest you do not torque more than 35 lb ft

[David Kemp]

As a beginner in flat four Jowetts I am learning all the time.
I discovered while assembling my motor I had a series two oil filter holder not a series three.
Some one in the past has also hacked mine about, though repairable, I am looking now for a series three holder.
The photos below show the difference.

[Keith Clements]

JT has a few topics on the filter housing, so use the search facility. Many blocks and housings have had their galleries modified to improve oil flow.
Good luck in finding a suitable housing but make sure all holes and faces mate. Perhaps do the O ring mod

[PAUL BEAUMONT]

There are principally 2 filter housings which differ in the size of the oil galleries. It is not really feasible to convert a small bore part to a large bore one. JCS May have a large bore one! The next problem is that Jowett only specified one gasket! Today JCS stocks 2 variants of the gasket to reduce sealing problems there

[Srenner]

Well, I'm going to go 180* from the above and say that the earlier housings can be modified, BUT that means switching to modern fittings and not using original style banjo fittings. And certainly it would be easier to get a later unit from JCS!

The bore in the housing from the oil pump can be enlarged to the Series 3 size through cautious use of increasingly proper size drill bits. The feed hole inside the housing cavity also needs to be enlarged. IIRC, bores to the two case halves are the same in both housings.

The factory banjo bolts are the reason modern fittings are needed. The smaller banjo is a choke point and limits flow. The TPI on the banjo bolts is non-standard ( to the rest of the non-Jowett world), so enlarging the ports on the early unit is rather easy. From there, I used -8AN fittings, but perhaps a metric banjo size might work. In one case, the aluminum AN fitting was welded to the housing.

I will post up some pics of my modified early flat base that was in use prior to the addition of the oil line ports. Mods were made to convert to a remote mounted oil filter. It will be so nice removing an oil filter without sloshing oil all over the top of the motor!

[David Kemp]

Please post photos i need all the ideas I can get.
I would appreciate any ideas on mounting the oil cooler, as I have seen them mounted in multiple places.

[Keith Clements]

I fit my oil filter on the jup above the gearbox on the sloping foot plate of the scuttle.
In the Jav i put above the air intake tube in the wheel space under the mudguard.

[Srenner]

Pictures of a modified early flat base and an unmodified small banjo bolt one.

Machined a cover plate held in place by socket head screw. Two ports located to maximize the internal configuration of the base. Tapped for 1/4" NPT x -8AN oil fitting. Internal passages modified to increase cross sectional areas. O-ring grooves machined into sealing side of plate to seal "in" from "out". Used the original groove to seal the plate to the base. Drilled passage from oil pump to match Series 3. Contrary to my previous post, I did enlarge the feeds to the block to larger Series 3 size. Yet to be installed.

Small banjo bolt base. As seen in the flat base, there is room to enlarge all the ports without breaking through the mating face. The small inlet hole in the cavity needs to be opened up.

With the pressure relief valve removed, it's easy to see the passage from the top bolt to the cavity is choked off by a fairly small drilling. Both the banjo location and the floor of the pressure relief chamber need to be enlarged. The hard part is reaching deep enough on the transverse passage at the bottom of the base to get it opened up. One might argue that after getting past the right side hole (2,4 cylinders), the restriction is simply the same as that directing oil to the block.

Easier to buy a Series 3 from JCS!

Forgot to mention that after all the internal work, drill and tap the ports for modern fittings. I'm now thinking that up-sized metric banjos might be a good solution as it would look somewhat original.

[David Kemp]

I have sent message to JCS via this site, I am not sure if it went through, is there a way to check?

[Keith Clements]

I assume you sent an email using the spares@jowett.org address. Yes there is a method but I am not going to chase as I am at Goodwood.

[David Kemp]

Hmmm this housing is a real learning experience . while waiting to see if a series three housing is available I decided to at least get the mounting bolts ready as I have none.
Seems series 2 uses 3/8 bolts to clamp the housing down, however series 3 uses 5/16.
I am guessing to allow for the larger oil holes,
If I can't get a series 3 seems I will need to modify the series 2 even more.
Does anyone know of any other differences ?

[PAUL BEAUMONT]

Pretty certain JCS has a few late housings. I was unaware of the bolt difference. Many thanks for that

[Keith Clements]

Some of us have extended the depth of the securing bolts and fitted longer ones. Fitting Helicoils also allows more torque to be applied.
viewtopic.php?p=44897#p44897
viewtopic.php?p=23595#p23595

[Srenner]

Beg to differ on the 3/8" bolt size. Both of my flat, as well as all the small banjo and large banjo oil bases on hand here are a nominal 5/16". The actual bolt hole size is around .345" on the ones not mounted on a motor. All of my blocks stamped E0, E1, E2 and E3 have used 5/16" bolts.

I'm thinking your parts have been "improved".

[David Kemp]

Looking at my series 1 cases they are 5/16 bolts. I feel your comments Scott that the housing I have is "improved" is correct.
one bolt hole is 3/8 the other 1/2 inch oval. Paul I am at a standstill , can you please assist through JCS?
I have heard nothing, & though this is not critical as I am not driving the car, I need the housing to finish the engine rebuild.
I would like the chassis a driver by Xmas,