Tuning PMO Carbs with a difference?

[mycar]

You should also consider Clewett's crank fire system.

https://www.clewett.com/index.php?main_ ... 1_13_14_18

MSD.

https://www.holley.com/brands/msd/

And 123 distributors.

https://www.123ignitionshop.com/gb/12-123ignition

All these systems have been fitted to cars here on DDk at one time or another.

[911hillclimber]

Over the last few years I've considered what to do with this car, Subaru engine, turbo and an easy 360 bhp, have such a car before this Lola, stunning engine and box.

Boxster engine and box, bit too big to fit into the chassis, water and an awkward gearchange route needing cables.

Sort this existing engine to Rev and keep it on carbs with Megasqirt on the ignition, rolling road needed.

All are expensive, the Impreza engine is the cheapest and gives the best bhp/ £.

Lastly, I love the air cooled engine in this car as the right engine for the history of the car and age, 1978, so nostalgia is an influence.

All this has just been put deep down on the list of the 911hillclimber, well below the new front door that is on the top rung.

[rhd racer]

I struggle to see the argument for an engine change to avoid a rolling road session costing £200 ish with an old school carb specialist Graham to be honest. Even throwing in a little investment for improved ignition, which once set up / mapped will never need touching again seems a very sensible idea.

If you were getting into the whole gearbox thing, then Boxster gearboxes come with cables attached so it would be super easy to just run through the chassis and use an OE gear-lever on a little mount. The last thing I would do is a scooby-swap, especially if you are considering your last season or two, I would get out there and enjoy the car as much as possible. Just do a few little jobs to enhance the experience and improve saleability when you decide to move on.

Cheers
Wayne

[hot66]

Have a look at ‘home built by Jeff ‘ ( he posts on here ) latest project on YouTube .... putting a cheap Audi v8 into his boxster ... mates straight up to the boxster gearbox..... but surely a bit of the point of your car is that it is a bit retro and fun , seems to me it suits having an air cooled 911 motor for this reason alone

[911hillclimber]

Yes, seen the 'V8 changes, interesting the parts mate.
The rolling road session will never stop at £200.
The carbs will be a mystery to most even though most of the jets are from the Weber dcoe range.
Some will mess about for ever getting things as good as they can make it all at my cost.
The bill from Bob to dial this combo in was £1200.
Also, with restrictions, getting to someone is not easy.

The chassis cannot take giant power increases, or rather torque, so about 300 may be the max.

Must admit I have not looked for a rolling road locally who would convince me the session would be positive.
Aldon would be the obvious choice, but been through that before.
Hitachi is another, and that was not conclusive.

[dragonfly]

I thought most of the Tuthill Safari rally cars run 3.0 on PMO carbs. If so they must have the setup pretty sorted

[911hillclimber]

They must have a tame RRoad somewhere, but can't go to them due to a past Issue over a gearbox...

[Nine One One]

I am sure that is long forgotten?

[911hillclimber]

When I've been crossed I've been crossed.

Before the car went to Bob's I tried Hi-tech who are local and have a big historic race car support operation, but most of their work is F3/F3 FF etc. They struggled with the triple webers mainly because they didn't have the jets, but the PMO carbs use DCOE jets.
They failed to sort the engine and were professional enough to say so.
Might be different now after all these years, so will contact them and see.

[neilbardsley]

They must have a tame RRoad somewhere, but can't go to them due to a past Issue over a gearbox...

Tuthill use Northampton Motorsport RR. I heard a few good things about them? Call and quizz them about their pmo experience

https://www.northamptonmotorsport.com/



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[911hillclimber]

Thanks Neil, I've been told that on another forum too.
A friend has just had his Mallock tuned there and was very impressed by the whole procedure but hasn't run the car up a hill yet.
Twin DCOE webers.

They use a picture of tipple webers on their web site, re-assuring!

[Richard M Knight]

Completely off topic but looking at your engine pictures how does the cooling fan work horizontally?

[MikeB]

Graham

Should have asked this earlier, when does the car pop and miss?

[911hillclimber]

Mainly at tick-over, occasionally on the hill when off the throttle coming into a bend.

Possibly an inlet gasket, been the culprit before and I end up replacing all the top head/manifold gaskets. I make my own now using gasket paper and a number of sharp blades, bit tedious, but quick that getting them from PMO.
To my knowledge, there are no spares outlets in the UK, just sellers of the full kits.

Expect to fire the engine this week and will spray around the interfaces with carb cleaner and see if a cylinder changes note. This method worked last time a treat.

Northampton Motorsport charge £110 + vat / hour and on average take 3 hours to do a car; add another hour for something unusual so about £550 plus parts such as jets I'm sure = about £600?
Add a CDI ignition to gain more from the exercise and the bill will be close to £2000.

Hard to justify the cost against the performance (time) benefit as in 2019 my fellow class mates were 3 seconds faster in places, sometimes 5 seconds.

Anyone reading this who hill climbs will know what it takes to close that time.

Just to put this into perspective, Paul Howells in his RSR will cover the hills I do faster in a car 2 x the weight, about 60 bhp more and FAR more bravery!

In fact, £2000 spend on driver training would probably do it!

[MikeB]

So if it is only a idle or trailing throttle why worry? It’s not affecting performance.