Building an engine for Economy
Turbo Mini Forums

Jean, excuss my ignorance, maybe not, but certainly more than a wet setup, considering need for cam sensor, dual widebands, sampling tubes etc. to do the job properly. As ill need a new head anyway, the SC 7 port looks quite tempting. I plan to make my own plenuem & use MS3 ecu.

Class C 3rd Place Avon 2011 14.18 @101mph

It's going to be difficult to package long inlet runners with a 7 port head. And if economy is the priority, that would be an important part.

Jean

http://www.jbperf.com/

What kind of length are we talking? I could move the plenum under the snatch panel on the clubman. I have about 90mm for the runners if I dont cut the front. ie Head face to plenum. So 150mm in total.

Edited by alaskanow0 on 9th Jan, 2012.

Class C 3rd Place Avon 2011 14.18 @101mph

Another foot should do it :)

http://www.starchak.ca/8port/efi.htm

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

If you are going to make the plenum anyway isn't it worth considering the 5 port with port injection? The engine could be pretty standard for the performance you are after.

My main concern is making the plenum / inlet manifold, the cam sensor and sampling tubes should be reasonably straight forward.

I would put the extra cost of the wideband, cam sensor and sample chambers at around £200. That's £150 for the 2nd wideband, £25 for a cam sensor in a dizzy body and £25 for tubes and fittings for the sample chambers. If you have your own fabrication facilities, then that should be it.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

john your right! i think gary missed the "Building an engine for Economy "

i run a 2.7 on 10's with a T2, i do a lot of motorway in the clubby,
no idea of mpg, but i love the 2.7 on a cruise.....

Edited by alaskanow0 on 11th Jan, 2012.

Class C 3rd Place Avon 2011 14.18 @101mph

out of interest, what size valves and cam is the 7 port running currently?

Currently 36x29 valves, smoothed ports, throat area opened up, with SW10 cam, 10.5-1 CR, 1.3 Rockers. It made 101 bhp.

Compared to same engine with Vmax Scart stage 4 36x31 head @ 10-6-1CR that made 84bhp.

I found the webbers very smelly, the engine ran more lumpy and was off cam until 3.5k, instead of 2.5k. So the plan was to use some AT Throttle bodies to sort out the bottom end and hopefully fine tune the top end power. But now thinking of swapping the turbo on the clubman and going all out with the 7 Port n/a on my lightweight mini for track days and class B. Still only thoughts

Edited by alaskanow0 on 11th Jan, 2012.

Class C 3rd Place Avon 2011 14.18 @101mph

The throttle bodies will help with the low end response, but you'll never get that combo to give good road economy.

For good economy and running a 2.75 diff, you need high torque/VE at 2-3k rpm. So low overlap cam, small valves/ports and effective scavenging are required.

Edited by Paul S on 11th Jan, 2012.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Ok, thats prety much what i was expecting to hear,

my head is also 36x31,

interesingly I didnt have running problems on my last engine (1380 Turbo phase2 cam 1.5 rockers 8.5 cr)
but on the new engine (1380 turbo, RE13T cam, 1.5 rockers, 8.2:1cr) it didnt like cruising at about 2000-2500 rpm would miss and buck, I've largely cured this by richening the mixture up to 12-13:1, interestingly I have changed te injector today for some lower flow ones that should have a better spray pattern, and straight away it will run a leaner mixture more happily and the exhaust smells cleaner.

I think the webers are not helping due to the big droplet size, going to injection (assuming the spray is fine) should be a big improvement,

on mine the stagnation will be worse bacause there are no butterfly's in the runner to help speed up/ disturb gas flow at low throttle openings, and also the RE13 has a RIDICULOUS 50thou duration for the seat duration, (think in terms of a 296) so most of the time the valve is wide open saying come on to the air...

my next move is a set of bike throttle bodies, (as my plenum is getting a bit tired anyway) on a long manifold to give the fuel time to evap to hopfully get some inertial ramming and pulse gain.

that said mine is quite drivable, but i think the low end is boosed by the vnt triyng to come on boost as low as 1800 rpm,

950 turbo diesel on veggi oil... Think out of the box!

[X] nail here for new monitor

Paul, I wasnt really concerned about economy previously with this setup and was running 3.44FD. But plans to do the long distance Italian Job run, means I will need a comfortable quiet car. I like the challange to create a turbo'd car that will return 40mpg with a full load and possible trailer specifically for this event. I know I could build a non turbo, but that would be no fun. The Webcon 7 Port really would never be able to return what am looking for and maybe not the SC 7 Port, due to needing longer runner lengths.

It all seems a compromise,

Edited by alaskanow0 on 11th Jan, 2012.

Class C 3rd Place Avon 2011 14.18 @101mph

Edited by alaskanow0 on 11th Jan, 2012.

Class C 3rd Place Avon 2011 14.18 @101mph

Spot on :)

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Edited by alaskanow0 on 11th Jan, 2012.

Class C 3rd Place Avon 2011 14.18 @101mph