Javelin horse power

[David Kemp]

The question I would like to ask is, what is the most reliable horsepower possible to get out of the Javelin motor. & what is the limiting factor?
I ask as the Wylie Javelin is supercharged, & Augustins raced their Grey nurse boats with Javelin motors, there fore grunt can be obtained.
In the past people have said the bottom end is the weak point. But other discussion in this forum, thinks an engine built with modern bearings is OK.
Others have mentioned head gaskets, but Neil Moores Jupiter runs I think Wells ring gaskets successfully.
Like wise if getting power to the ground is what matters an easy improvement would be thermatic fan & electric water pump(these are probably now cheaper than a replacement Jowett item)
If any one has uprated their Jowett ,what works? If I ever modify a Javelin I don't want to go the Small block Chrysler route as someone has done. I think if an engine swap was going to be done
something more like a Mazda rotory would disturb the handling dynamics far less.

[Keith Andrews]

I don't want to go the Small block Chrysler route as someone has done. I think if an engine swap was going to be done
something more like a Mazda rotory would disturb the handling dynamics far less.

I definately would not go rotary...or the Chrysler sb 1st choice would be the buick 3.8 (think your vauxuals may have them.
Dynamics..you pump resonable HP no matter what suspension brakes, chassis is all going to have to be beeefed up..
But are you looking to HP more high speed ovail track or torque street track....vert different monsters

As to breaking bottom ends etc...the root of the cause is dynamic balancing , building design stuck in british pool fuel instread of moderm fuel charactoistics... dynamic compression, cam profile, and timing.
Either one of these if not right will drop a crank or rip bearings no mater what super duper stuff is used to make them.

[Forumadmin]

We should ignore discussion of what engines might fit into a Javelin as it depends on how much structural damage you do. We could make a list of all the 'failed' attempts as none, as far as I know, produced a car that would go around corners as well as the Palmer set up. Sure there are those that have managed to move in a straight line and some which are arguably acceptable aesthetically.

On the subject of modifying a Javelin engine, it also depends on how far you stray from the original. If you stick with period modifications and the original block and crank then you are limited. Superchargers , overhead camshafts , multiple exhausts, strengthened sump were all period. Modern pistons and liners, valves, springs, pushrods, camshafts and bearings are all possible, If you can afford redesigning and fabricating parts then start with the crankcase and bearing housings and redesign oil delivery perhaps with dry sump. Design a new crankshaft as was fitted to the Monte Aston Martin I rode back in from Monte to Nice (great if you can afford such a one off).

I studied the engine and talked with the Wylie mechanic, the mods they did were extensive; but were modest compared to what could be done with the Mclaren design team available.

Probably the best parallel is to study the early Porsche engines or the later Subaru to see what could be done and how much development would be required. http://en.wikipedia.org/wiki/Flat-4

[george garside]

totally agree with above first paragraph. Without a Jowett engine ( whether lightly or heavily modified) it would become a bastardly contraption rather than a Jowett! There are plenty of unloved 'old cars' with big hollow spaces under the bonnet that can be endowed with v8's in line 6's or whatever odd desisres some people have.

george :

[Forumadmin]

To answer the question then you need to ask a few more.
Reliability is not something that is easily measured. Do you mean 100 race miles or 20000 sedate road miles?
Your references to the racing Wylie suggest you mean racing. Most race engines need to be rebuilt every few races anyway. All components in a racing engine will be stressed close to their maximum. It is usually dynamic stress caused by imbalance that causes failure and that is usually worse at high revs. The Jowett engine is generally limited to 5000rpm although I regularly ran for short periods at 7000rpm on my race engine. That was after a lot of work everywhere lightening and balancing. In 40 years of driving Jowetts vigourously I have never had a crankshaft break. In fact the only real disasters have been dropped valves after long motorway thrashes and one valve spring cap after a few years racing. I have had one slightly bent push rod, a small end circlip breaking and eating its way through the piston. All these incidents were removed from the equation on rebuild through modifications. Most incidents are traceable to poor assembly or maintenance or unsympathetic driving.

Are you limited by the regulations of the event you intend to enter?
Do you stick to 1500cc and do not fit larger pistons?
Do you retain 30VM carbs?

90BHP is about what you would expect from adding larger pistons, crack tested and balanced everything, flowed heads and valve ports, Dellorto carbs with full flow filters, lightened valve gear and stronger springs, good profile for camshaft. You might get some more with tuned exhaust system to get the power at higher revs and stiffening of the crankcase to achieve higher revs but the Jowett engine is really giving broad torque; not power.

[Keith Andrews]

We should ignore discussion of what engines might fit into a Javelin as it depends on how much structural damage you do. We could make a list of all the 'failed' attempts as none,

Certainly not the attitude to threads others have started on well engineered rodding of jowetts....
Surely the failed attempts should be made far greater notice of....thats when people die thru stupidity..

So lets clairfy...posting of none jowet modification are now no longer acceptable or not?
And commenting on such mods in a positive manner is not also accepted anymore?

Some of use have interests beyond jowett...out into other areas such as American Desoto, ford, Chev, and hot rodding based on English eurpean AND Amercan rod, bring a huge amount of practical ecperiance.

[Forumadmin]

Keith,
There was no intent at stiffling any discussion, just expressing an opinion. But if you can show me a Javelin hot rod that actually does go better than the original around corners then I would love to have a ride in it.

[Keith Andrews]

Hotr Rods are purpose built..and Im not talking backyard boy racer wantabees...
Track is striaght line 1/4 mile or cruise...
So a common running gear is jag....to take the engine and diff weight distrubution.
As discussed in prevuios posts one would have to have a death wish to even use the jowerr chassis and/or suspension with a V8 even a modern LS3 ALmotor ..then add the Hp...one is talking anything from 300 to 700.
So all one has is a jowett body shell with air con , electric windows, etc around a modern aftermarket performace running gear...that goes fast...
So done right for handling/ performace around cnrs...javlens are impressive, even on todays standards if HP is not taken into account...Add the Hp and jowet technology is left in the dust...
Your 'British' concept of a hot rod is very much different from that of most of the rest of the world...

[Jack]

I did a bit of research on possible options for this before we got into Project B, and the only sensible option I could find was to swap the Jowett engine for a Subaru. Similar engine layout, very similar dimensions (width, engine mounts, depth and overall weight and size) and fairly large amounts of power in a range of sizes available. Note that the external size of the Subaru range is very similar from the 1.6 right up to their 2.5 litre engine - assuming that you only went with naturally aspirated instead of the twin turbo engines - these are massively powerful but won't fit in the gap and would be just way too much power.

The almost identical size, weight and flat 4 design should mean that it corners in a very similar fashion to a standard car, I can't see that it would make any more difference than having a passenger in the front, the difference in weight was about 10kg between Jowett engine and gearbox and Subaru when I looked into it.

There's also a number of specialists who can convert a Subaru wiring loom fairly easily, this is fairly common on VWs, campers and beetles are being modified to provide either more comfortable cruising and reliability on modern motorways or as hotrods designed for pure speed.

The downside to the use of Subaru engine is the need to sort the 4x4 into rear wheel drive, but this is again a fairly common modification - the Japanese scene have been modifying the gearbox with a simple kit in order to build drift cars out of the Impreza or Legacy.

We did have lengthy discussions about potential modifications required on a thread a few months ago, where the strength of the diff and halfshafts was discussed - it seemed clear that you could double the horsepower fairly easily without major modification, but once you get into 100+bhp there is a lot of torque on parts not designed for those forces.

Jack.

[Keith Andrews]

the only sensible option I could find was to swap the Jowett engine for a Subaru. ........but once you get into 100+bhp there is a lot of torque on parts not designed for those forces.

Which makes it not sensable, basically one is moving into dangerous.

assuming that you only went with naturally aspirated instead of the twin turbo engines ........
The downside to the use of Subaru engine is the need to sort the 4x4 into rear wheel drive,

We still own a 1988 subaru omega..the 1st car my wife had and still a great little runner....its the EA82 engine baically used in microlites, carbed, and is not 4x4 as most ppl believe subarus are...the leone is very similar....and we have other jowetters in NZ with Omegas and leones... they are not a 'performance' even so dropping into a javelin or any old car certainly means basics like strengthen chassis, sorting better/ bigger brakes...dont know how the diff would go...
Wireing is no big deal with non fuel injection.
The easiest way would tosimply bolt up the front and rear drive train assembles from the subaru...includes suspention diff , brakes, steering, engine gearbox etc.....the big issue would be the macpherson struts geometry under the fenders.
Even that is no major ...no more difficult than using /doing the same from a XJ6 into say a American international truck or Ford F100 or 55/56 chevy.
Even use the power brake units and cylinders
Any welding mods , to chassis or say shock towers requires a certified ticketed welder.

You have a car that still rides very well cnrs better,,and lets face javlens are good at that (but with more ?) good power assited brakes, 5 speed gearbox..and sit inside the javlen...and its still a javlen

[Jack]

I guess it depends if you are building a hotrod, or if you are merely modernising the engine and adding a few horsepower for modern motoring.

Agree that 100+bhp without major modification would be dangerous, but keeping it to around 100bhp seems reasonable.

Personally if I was going to "upgrade" the engine then I'd use a more modern Subaru engine, there's a few options around 100bhp, the 1.6 and 1.8 engines deliver this, or even the more common 2l engine, which would make the Javelin quicker and able to cruise comfortably at 70mph, you could just mate the engine and gearbox (with minor mod to remove 4x4 and make it RWD) to the existing diff and other running gear.

That would make it a modification, as opposed to a complete rebuild. Realistically you could leave most of the rest of the car with minor tweaks, servo brakes would help, if drums all round are enough to stop 3 tonnes of our motorhome in a hurry it is enough to stop a Javelin with slightly increased power.

Ultimately a lot of this depends if you want to build a car or just modernise and increase the power a bit, without massive amounts of work.

Jack.

[Keith Andrews]

Ultimately it would depend what would pass engineering certification...I dont know the law in the UK, but down under the days of dropping a more powerful engine in or even modding an orginal engine, most modifcation .... have long gone....
Resulting in safer roads, and eliminating idiots with death machines.
When these laws where 1st proposed in the mid 1980s, there was a lot of controversy, espec in the Hot rod and ralley, motorsport camps...., and after a lot of negoiation, submissions....it is, has been a good thing

if drums all round are enough to stop 3 tonnes of our motorhome in a hurry it is enough to stop a Javelin with slightly increased power.

Are u suggesting putting the motor home sized drums on the javlen?..
Maybe javelin drums would be ok IF the car has 13 " rims.....a lot of science the that area to.