2800 V6 based May Turbo

[Willi]

This is a 2800 based May Turbo engine I built. It runs a 72mm stroke crankshaft (modified 2.9) and 1mm overbore with Accralite pistons, so almost exactly 3000cc. Slightly reworked unleaded heads, 8.7:1 CR, Kent V6 T21 cam. Original rebuilt KKK 3 LD turbo at 0.7 bar boost.

[Dyno]

Awesome engine !!!!!!

Pictures of the engine? blow through carburetor ?

[beeRS]

I guess that’s about 275bhp. Nice.
Good flat torque curve too.
Would love to see some pics too.

[Willi]

Thank you both.
Yes, blow through carb, almost stock Solex 38 EEIT. Block is wire ringed.

[Dyno]

any pictures of the fully finished engine?

[Willi]

No, unfortunately I don't have any. The owner collected the engine from me as in the picture above and completed it with the parts of the previous engine and fitted it by himself. Will ask him for pictures though. Which details are you specially interested in?

[Dyno]

Would be nice to see the complete engine with carb and turbo setup as complete

[Big Daft Lad]

Double post.

[Big Daft Lad]

Thank you both.
Yes, blow through carb, almost stock Solex 38 EEIT. Block is wire ringed.

I know this thread is two years old but what modifications are required to the carb?

[Willi]

The carb is unmodified as far as I know. I have only built the engine, the setup was done by the owner of the car and by a company near to him. But I will speak to the owner soon again and ask him about the carb. On a stock "May Turbo" setup with 200 HP on a 2.8 V6 the Solex carb was completly stock anyway

[Big Daft Lad]

Thanks Willi, any further information would be gratefully received.

[Willi]

I had spoken to the owner of the car yesterday. The carb is a completely stock Solex EEIT, they only changed the idle jets to one size up, from 47.5 to 50. And they recurved the Distributor.

[Big Daft Lad]

Thanks Willi that's brilliant!

It's crazy that the carb works without modification with a turbo blowing through it. I've got a 38 EITT to go into my engine (the original has been swapped for a 38 DGAS)

I'm planning to put a small turbo on my TVR. I'm only looking for about 180bhp so hopefully that should not be a problem. I've got a vacuum canister that retards the ignition and I'm going to feed the carb with a high pressure pump via a rising rate regulator.

[Miniliteman]

Why a rising rate regulator?

[Big Daft Lad]

I'm not sure if the Solex needs it but if you put 8psi of boost through a Weber that needs 3psi fuel pressure you're not going to have any fuel in the carb. The fuel pressure should be boost pressure +3psi

[Willi]

There is a regulator from Malpassi (should be available through Burtonpower) that does exactly the right job. That was originally a Maserati spare part for a car with a blow through carb. And yes, the Solex needs that, too.
180 bhp should be realistisc from a stock 2.8. If the engine is in good condition you should see this kind of power at around 7 psi of boost.

[Big Daft Lad]

I was planning to use this regulator.

[katana]

That's an excellent regulator used on everything from Metro Turbo's to Lotus Esprit Turbo's. But whilst that covers accurate boost related fuel delivery, if you don't ensure that boost pressure is fed into the float bowl also you'll get a massive lean condition through to no fuel flow at all! All of the OEM's either used modified carbs to allow boost pressure into the float bowls or enclosed the whole carb within a plenum / airbox that was pressurised.
The bike world is big on 'add-on' turbos with carbs, & use pitot tubes in the boost pipe to provide better dynamic pressure to float bowls and FPR to boost fuel flow fractionally as boost builds!

[katana]

Double Post - bloody slow software ! ! !

[Big Daft Lad]

if you don't ensure that boost pressure is fed into the float bowl also you'll get a massive lean condition through to no fuel flow at all! All of the OEM's either used modified carbs to allow boost pressure into the float bowls

So if I drilled and tapped the side of the float bowl then attached a small pipe to the inlet pipe would that be good? I'm assuming you need a one way check valve on this?

[katana]

Most carbs will already have a float bowl vent - if they didn't the engine wouldn't get any fuel as a vacuum within the bowl would result. Whilst a connection to the manifold / plenum would work to provide boost pressure, this through years of observation / experimentation with Bike blow through installations, shows that a 'pitot tube' positioned in the boost pipe to the plenum provides a better 'signal' to the FPR, Wastegate and of course the Float bowl. It is more dynamic and can be 0.5 - 1psi above measured plenum pressure and so counteracts a little lean cough when boost kicks in. A J shaped pipe, 5-6mm ID bore facing into the airflow from turbo usually works. And, no - no one way valve required.