Goodwood blow up.

[Srenner]

Several good points made in the comments above.

Phillip: Vintage racing is an odd little world. Some are there for fun, others get their egos involved and will go to extremes. Most clubs have a .040" or .060" overbore rule. I have seen Panhard 850cc motors bored to 1200cc. Shoot, my first Jupiter motor used 40hp VW pistons at 77mm! I felt I had to do this as the only other Jupiter racing in the US had a NZ built motor with that spec. And there's the escalation in vintage racing.

With the exception of Formula cars, IMHO it's not considered cheating unless you have finished ahead of someone who complains to the organizer.
Look at Julian's overall build and stop to think he's still roughly mid-pack. Man, I want those front brakes!!!!

Chris is correct on the "mass" produced racing parts. They are still costly, but way cheaper than on-offs.

We all could benefit from a livelier motor. A better piston design to take advantage of modern rings, lighter pin, perhaps with a small dome to bump the CR for a small HP gain without needing premium fuel. Real gains in performance would come from a modern cam design and better head flow. Lighter flywheels. Tons of room for improvements.

Perhaps try for a modest 10 to 15 HP bump. A better cam, lighter rotating parts and better breathing might be all it takes to get there without stressing the motors.

[Keith Clements]

What the last couple of weeks have shown me is that better parts are available and work, but you have to accept spending say £5000 to build the engine. JCS offered new cams at over £500 but I think only had one taker. A high lift cam from Piper is almost off the shelf and will set you back about £600. But then you will need valve gear that will be another £500.
Various piston options are available but finding a set of forged ones that can be modified can prove difficult.
Some more discussion and marketing of the ideas should be done through all the Jowett fraternity.

[PJGD]

Ignoring for the moment the multiple technical issues that it could involve, would fitment of a supercharger be acceptable to most event organizers?

[Keith Clements]

For most events a supercharger would not be allowed even if it could be shown that they were fitted in period as some attempted in the 1960's with some bad results. I thought the Wiley had a supercharger or am I wrong?
Many events also have classes so it is likely that, if it were allowed, a supecharged Jowett would go into an even stiffer class.

Here is another thread. viewtopic.php?p=16234#p16234

[PJGD]

Keith,
Yes, you are correct; the Wylie Javelin did have a chain-driven Marshall or Centric or Shorrock supercharger at different stages of its life.

The engine had many modifications made to it to handle the power increase, and these are detailed in the attached correspondence that I had with Bruce Polain two years ago [I can't imagine that Bruce would have a problem with me posting our correspondence here, but if he does, we can remove it].

Full details of the car with photos can be found here: https://primotipo.com/2018/09/14/the-wy ... n-special/

[PJGD]

Here is the correspondence:

Re Javelin Engine from Bruce Polain.pdf

[Keith Clements]

I purchased my first Javelin s/h with 20,000 miles about 1955 and entered in club motor sport for some years winning some forty class awards against the like of Morris
Majors, Peugeots and Simca etc. The engine received a mild port and polish and the muffler was modified by inserCng a heavy gauze pipe to go diagonally internally from
inlet to exhaust within the muffler thereby avoiding two 180 degree turns.
The result was lowering a standing 1/4 Cme from 21.5 to 20.4 – though it was a trifle noisy. Then raced it at Mt Drui=, Schofields and Mount Panorama at Bathurst where
we were electrically Cmed at 86mph.
Having now achieved an interest in Jowe=s - purchased the Wylie Javelin racing car (it had competed in the AGP).
As far as its performance in a standing 1/4, this was in the 16's but progressively over a couple of decades I lowered it to a regular 13.2.
How I achieved this, involved many things and some of which are perhaps relaCve to your arCcle:
a) I ground and polished the rocker arms.
b) Manufactured lighter weight/stronger pushrods using chrome molly from an aircran store which tubing had an id that I could thread to take the screw ends of a
standard push rod.
c) Relaced the spacing springs on the rocker shan with brass tubing – to eliminate the torsional acCon of the springs and contain oil for rocker shan lubricaCon.
d) Made up replacement valve guides using naval bronze with the exhaust a trifle longer to parCally protect the valve stem from exhaust heat.
e) Having acquired heaps of valve spring from the Agent when closing down, I used a valve spring pressure tester to test the result – as you observed those from a
hydraulic engine were much soner so they were discarded. Then found large variaCons in tension – so sorted them into like tensions.
f) Made up a 3/8 perspex cover for the combusCon chamber with a small hole and measured with pipe=e and kerosene the capacity of the combusCon chamber – found
many had excessive capacity due to valve seat wear with valves seaCng below their normal level thereby reducing compression raCo from 7.2 to 1 down to 6.5 or lower.
g) The club recommended new seat inserts but my method was a li=le different. Found a valve manufacturer who machined up specials - 1/32 over size for head
(thereby cancelling the need for inserts). In addiCon, using his recommendaCon, we changed the profile for the inlet to that of a CorCna (which gave a nice looking sweep
to the intake gas – the extra weight was offset by a dish in the crown). For the exhaust the head was crowned which looked the thing to do to improve exhaust flow. The
crown on the exhaust equalled the dish in the inlet so combusCon chamber capacity remained unaltered)) Next we made up alloy spring retainers - then set the valves up
in head and measured the distance to the spring locaters that rest against the head – any variaCon was corrected by use of shims under the spring locaters.
i) Welch plugs were removed from the heads and the water jacket given a mild grinding/polishing to improve water flow – should be remembered that the engine would
ulCmately be producing some three Cmes original power output. A surplus head was bandsawed into secCons and from that we deduced the water flow and consequent
cooling could never work at the opCmum, as flow was impeded by areas that would always retain an air bubble. The soluCon was to drill in from outside and run a
relaCvely minute tube from these pockets to the swirl pot in the cooling system and problem solved – no more over heaCng.
Much more was done in relaCon to alternate con-rods and clutch, plus oil and fuel delivery enhancements - also sump and flywheel modificaCons plus a girdle but the
above is hopefully relevant to your arCcle.
Cheers.......BP
<wj engine ohv.jpg><WJ girdle.jpg>
<Jowe= Mono-Head Concept.png>
<Cover dran 2.jpg>

[Keith Clements]

From: philip@philipdingle.consulting
Subject: Re: Javelin Engine
Date: April 13, 2020 at 5:43 PM
To: Bruce Polain brucepolain@ozemail.com.au
Cc: Ed Wolf eswolf@optusnet.com.au, Philip Dingle cetane55@gmail.com, Edmund Nankivell ed@jowettjupiter.co.uk
Hello Ed,
Having studied your cut-up head photos, my assessment is that the new clamp screw hole towards the center of the head and low down is clearly good - there is nothing to get in the way of that and nothing to worry about. The hole to the outside edge might be OK but it is very close to the exhaust port that runs down to the bottom face. This one would need to be test drilled to see if it becomes a problem or not. The third hole at top center looks like it might interfere with the spark plug bore, in which case it will need to move round a few degrees towards the head centerline, at which point it may begin to interfere with the rocker shaft pedestal if moved too far. Again, a test drilling is called for.
If you are in a position to make a test drilling, I can provide dimensional coordinates from my drawing to locate the holes.
Regards
Philip
On 2020-04-13 04:48, Bruce Polain wrote:
Hi Ed
As you have the dissected head why not do it live!!
From: Ed Wolf
Sent: Monday, April 13, 2020 2:45 PM
To: 'Philip Dingle' ; 'Bruce Polain'
Cc: 'Philip Dingle' ; 'Edmund Nankivell'
Subject: RE: Javelin Engine
Philip,
The mystery is solved.
Your attachments appear at the very bottom of the emails rather than where we expected to find them at the top.
I will now spend some time to study your drawings and then get back to you.
I have informed Bruce of the discovery also.
Ed
From: Philip Dingle <cetane55@gmail.com>
Sent: Monday, 13 April 2020 1:05 PM
To: Bruce Polain <brucepolain@ozemail.com.au>
Cc: Philip Dingle <philip@philipdingle.consulting>; Ed Wolf <eswolf@optusnet.com.au>; Edmund Nankivell <ed@jowettjupiter.co.uk>
Subject: Re: Javelin Engine
Hi Bruce,
Well, that is strange; it appears to be attached [as a .PNG file] to the email that I sent.
Anyway, here it is as a Tiff file - I hope this works for you. Let me know if not.
Philip
On Apr 12, 2020, at 9:28 PM, Bruce Polain <brucepolain@ozemail.com.au> wrote:
Hi Philip,
Your sketch not included <wlEmoticon-smile[1].png> (or do you mean that with your original email?)
The oil pickup was anyway modified to dispense with the original pickup (an odd shape that did not suit a baffled sump) and also to reach the small section of deepened sump which was part of our overall scheme.
Yes the blower was chain driven – anyway no room for a multiple belt pulley.
It gave no trouble – had in stock a few different adjusting sections for alternate pulley requirements from 6lbs in increments to 16lbs (and beyond which never used.)
I installed the chain guard but apart from that the odd squirt of oil (with a bit of molybdenum) was all it apparently needed.
Happy Easter – am also busy with a book on a local specialist manufacturer – if anyone reading this knows of any JWF owners or interest - please have them contact me.
Cheers.....BP
From: Philip Dingle
Sent: Monday, April 13, 2020 8:04 AM
To: Bruce Polain
Cc: Philip Dingle ; Ed Wolf ; Edmund Nankivell
Subject: Re: Javelin Engine
Bruce,
Thanks for explaining what you did with strengthening the crankcase; they look like well engineered modifications, and I see that the oil pick-up had to be modified to get past the sump
girdle. Also, it looks like the Marshall blower was chain driven; is that right?
So here is a drawing/sketch of my concept for what might be called a "mono-head" arrangement in which the liners are bolted to the head with a son copper seal ring in-between.
Cylinder head gaskets can be problem at the best of times and require to be well engineered if they are going to be robust, which the Jowett head joint is not. Ideally, the head bolts or studs would be evenly spaced for an even clamp load and they would all extend down into the crankcase to at least the depth of the shelf that the liner sits on. As it is, the differential expansion of the aluminium and the ferrous studs and liner mean that the clamp load reduces as the engine warms up.

In my concept, the liner is bolted directly to the head with just a son copper seal in between. The only force trying to separate the two is cylinder pressure acting on the narrow land on the inside of the copper seal, and piston friction which you hope will be quite low. Hence only a few small set screws should be adequate to maintain the seal. In theory the liner does not need to be clamped between the seat in the crankcase and the head, although one would probably set it up so that it is. The three M4 socket head cap screws that I am showing
would be torqued up aner the head has been installed. I would like to have used four setscrews (or more), but the three as shown conveniently go through the water spaces and miss the internal porting. The copper washer under the head inhibits water from mixing with the oil. Now the head gasket can be optimized just to seal the water spaces without worrying about the liner seal, and the torque spec can be relaxed. This is somewhat similar to the factory use of Wills rings.
Note that I have not converted an engine in this manner yet, but I might do so on the next engine that I rebuild. I just want to get hold of a scrap head first to confirm that my setscrew
locations are good.
Happy Easter!
Philip
On Apr 9, 2020, at 10:54 PM, Bruce Polain <brucepolain@ozemail.com.au> wrote:
Hello Philip
Was amused re your comment that our valve idea (of some forty years ago) would likely be eligible for a patent – as it happened the Jowett Committee rejected the idea as they only wished to be involved with standard parts – even though it then meant the expensive seat insert option.
Re block stiffness the first picture will show how we replaced the tin cover/cork gasket over the push rod chamber nipped up with a gentle tweak using a screwdriver with an alloy plate – no gasket and bolted to the block halves. Have no idea how mechanically effective it was but it made me feel better and certainly looked good.
No we did not use a steel girdle as I was very aware we already had a light engine and had no wish to add weight – so a thick alloy plate was the answer. This meant longer sump studs and much care with the design to plot the slots that the conrods would need to rotate – added to that were the scrapers to divert oil mist into the sump. The flywheel was about half the usual weight and due to the horsepower developed required an extra dowell and hi-tensile bolts to stay in position. It was also fitted with a smaller diameter racing clutch – again a weight saving.
As we were denied the opportunity (historic regulations) to use a dry sump, much time was spent with the application of baffling, oil pick-up and only partial sump deepening. It worked and as I recall only required normal oil capacity – many use a couple of gallons which equals more weight!
Reference to the photos you will note the half inch (internal) oil and fuel lines - the latter was at my insistence as I had witnessed with others the troubles they had with fuel feed when using alcohol. Did not use brass as nipples or connectors but steel nipples bore out to 9/16 into which small length of tube welded (half inch bore) meaning half inch bore throughout.
Was interested in your idea of improving head seal efficiency – could you please elaborate on the sketch enclosed earlier.
Ray Bell is a very old friend but as he is in Queensland haven't seen him for ages – will make contact and tell him of your interest in the Forum.
By the way Arthur positioned the Ford 10 water pump at crankshan level where it was belt driven off front pulley and therefore aided the thermo siphon effect from the rear engine to the front mounted radiator. Originally the water was transferred by some (ex war disposals convoluted gas mask tubing?) which lay on the floor and very much in the way – I changed to inch and a half alloy with only the return on the floor and the hot at a higher level.
Cheers....BP
From: philip@philipdingle.consulting
Sent: Friday, April 10, 2020 4:59 AM
To: Bruce Polain
Cc: cetane55@gmail.com ; Ed Wolf ; Edmund Nankivell
Subject: Re: Javelin Engine
Hello Bruce,
It is good to hear from you. Strangely enough, although having been a Jowett owner since 1965, I was generally aware of you and your exploits with the Wylie Javelin, but it was just a couple of weeks ago that a post on the TNF site that I visit regularly: https://forums.autosport.com/forum/10-t ... gia-forum/ I think by Ray Bell, that pointed me to the Primoto website that covered the car in detail. All very interesting.
I read with interest all the modifications that you made to the engine and would agree that they are all in the right direction. I was particularly interested in the changes to the valve heads that you made; I think that you could have got a patent for that idea since I note that MAN Truck & Bus in Germany recently got a patent for a domed exhaust valve, although in their case it was for strength reasons to counter the high cylinder pressures of modern highly boosted diesel engines.
There are two ways to get significantly more power from an engine; either increase the maximum revs, or stick with modest engine speeds and then add boost in some way: - both get more air through the engine in unit time and thus more power. Applying both methods together can be done but requires a very robust engine. Having a single central camshan with very long and heavy pushrods limits the ability of the Jowett engine to achieve high revs, and the lack of crankcase stiffness limits the cylinder head clamping force and sealing and thus the peak cylinder pressures that come with boosting. It is impressive that you (and Arthur Wylie) found a way around those impediments. Of course it does not help reliability, power, and robustness that the cooling system is totally back to front in the standard car, with the pump being on the hot side of the engine (if that is how Arthur Wylie arranged it).
You mention adding a girdle to the engine; can you provide more detail? I assume that it was a steel frame that sandwiched between the crankcase and the sump? For head-to-liner sealing I assume that Wills rings or similar were used? I have always wanted to cut up a scrap cylinder head because I want to look at the potential of retaining the liner to the head with say 4 long small diameter Allen screws that go through the head and into the liner flange. Then with a copper ring or similar in a groove in the liner flange [see attached sketch], cylinder pressure would have very little separating force between head and liner and the head studs would be relieved of all cylinder pressure sealing duty.
Looking at the photos on the Primoto site, I remember being surprised that the Jowett gearbox was capable of handling the extra power; it must have helped that the car was quite light.
Best regards
Philip
www.philipdingle.consulting
On 2020-04-09 02:19, Bruce Polain wrote:
Hello Philip
Just finished reading your 10 page summary of camshans etc and thought you may be interested in some actions I took in the previous century.

[Keith Clements]

Philip can you post the reference images please.

[PJGD]

Before discussing the graphics that I sent to Bruce Polain, let me just make a few comments on the subject of what it will take to build a robust upgrade to the Jowett powertrain. The first thing to do is to identify and prioritize the weak points. My list would look something like this:

1) Crankshaft
2) Head gasket sealing
3) Valvetrain
4) Piston
5) Cooling system
6) Ignition and electrical
7) Carburation and mixture control

Crankshaft: If you have an oval web crank then you are in reasonably good shape; if you don’t and a nitrided example is nowhere to be found, then a new batch of cranks may be called for in which case several design improvements are possible and should be adopted. These include having the oil drilling breakout for the pin on the leading side, not the trailing side as it is now.

Head gasket sealing: The lack of crankcase rigidity and the fact that the head studs do not go down to below the liner seating shelf, plus various other design flaws that all result in gasket sealing failures are well known. To overcome these issues once and for all requires that the combustion pressure seal be mechanically separated from the coolant seal. Today, the clamp load from multiple head studs has to serve both sealing functions but is defeated by lack of crankcase rigidity. My solution [not tested in hardware yet] is to clamp the liner to the head with either a soft copper or a Wills ring in-between. There is very little force trying to separate the liner and head assembly and so only a relatively small clamp load between the two is needed; all the head studs have to do now is keep the coolant in and retain the head/liner assembly against firing pressure - a much easier job.

Valvetrain: Increases in power come either from supercharging or from or from increasing engine speed while maintaining volumetric efficiency i.e. good breathing.. Until recently and with electronic controls, it was easier and cheaper to increase engine rated speed by moving to 4-valves/cylinder and OHC rather than supercharging; now there are many engines that are supercharged or turbocharged. In our case the Jowett engine with centre-mounted camshaft has a heavy valve train that is not ideally suited for good breathing at high engine speeds. We can either spend our effort and money on improving the valve train [e.g. light weight pushrods, and scientifically designed cam profile, etc], or not go for high engine speed and go with supercharging instead to get the power we want.

Piston: If keeping the engine displacement to just under 1.5 Litre is not essential, then a slightly larger bore such as 74 mm is probably a good option. There are a number of other features that can be applied if one were to go with a bespoke piston, such a a graphite or Moly coated skirt that is relieved around the pin bosses for low friction, a forged or cast piston, and wrist pin offset etc.

Cooling system: The standard cooling system on the Javelin/Jupiter is marginal at best and is likely to lead to engine unreliability if the power output is significantly increased. The problems arise because the water pump is an inefficient paddle style pump (think paddle wheel ship instead of a screw-driven ship) and because the pump is on the hot side of the engine ahead of the radiator instead of the “cold” side immediately after the radiator. This means that the cooling system stops working as soon as the engine overheats since the pump is unable to work with steam and engine damage e.g. cracked heads will result. Ideally, the coolant flow needs to be reversed from the way it is today.

Ignition and Electrical: Electronically triggered ignition using a modern coil-near-plug arrangement is likely to be more reliable and require less maintenance than the original distributor. This may however require a timing wheel with magnetic pick-up on the crank and/or camshaft. Likewise an alternator and geared starter motor should be planned for.

Carburation: Electronic fuel injection is not totally straightforward on engines with Siamesed inlet ports, but it should not be dismissed. This is a feature that has the potential to make the engine more tractable and with improved fuel efficiency. It would be worth investigating.

Anyway, back to the correspondence with Bruce Polain and my sub-assembly of liners to cylinder head, I started off by placing a tracing of the combustion chamber taken from the JCL cylinder head drawing over the standard Ø72.5 mm liner with centers aligned, so this showed me where a copper or a Wills ring could be located on the liner flange while still leaving room for three M4 set screws to hold them together. In the assembled state, the liner would be free floating in the crankcase and not sitting hard on the lower shelf so an o-ring is required here to seal coolant from the oil. The advantage is that much higher cylinder pressures that come with either higher compression ratios or from supercharging can be safely handled. A compressible gasket such as neoprene could be used to seal the head-to-block coolant joint.

Chamber Matched to Liner.png

Proposed Wills Ring Liner.png

Jowett Mono-Head Concept.pdf