MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGA - CARBS AND DIZZIES

Advice please.

My '57 Coupe is fitted with a Marina B series 1800 engine, HS4 carbs and standard 25D4 dizzy. I recently had the head gas-flowed, compression raised to 9.7:1 and kitted out with a branch exhaust, the cam profiled to Kent 270 degree spec, and fitted a cold airbox to improve combustion efficiency. Dare I also say that I also added a Datsun/Nissan 5 speed gear box?!

Whilst the improved performance is a delight and evidences a remarkable improvement for our local road conditions of long, undulating highways, byways and mountain passes, advice about alternative needles for the carbs and tuning the dizzy with revised weights and/or springs will be welcome.

In passing I put these enhancements to the test with good effect as one of 44 participating MGA crews that spent 11 days celebrating 50 years of the model over a route of some 4000 kilometers. But when we reached the coast (I live at some 1600 metres above sea level) the Coupe showed symptoms of fuel starvation with occassional stuttering and an alarmingly white/grey exhaust that had me adjusting to a few flats richer to little avail, thus also travelling with a bit of choke.
Joe Gates

Joe,
I'm using #6 needles in a stock five main 'B 1800 with the "Eurospec" distributor. It's fitted with standard MGA aircleaners and H4's. The exhaust manifold is stock MGA into a Falcon stainless MGA exhaust.

The best thing I've done is to weld in an oxygen sensor bung and install an edelbrock rich lean gauge. I was quickly able to dial in not only the correct needles, but also the correct viscosity damper oil. Over time, I expect to be able to monitor performance and make sure footed altitude adjustments.
BOL,
Doug
D Sjostrom

Joe,

Search the MGB technical section and you may find answers to your questions.

I use a Weber, so can't help you with your carb questions.

As for the distributor questions.
I posted this some time ago in the MGB technical area, now in archive.

http://www2.mgcars.org.uk/cgi-bin/gen5?runprog=mgbbs&mode=archiveth&archiveyear=71_2005.dat&access=&subject=71&subjectar=71&source=T&thread=2005060310432027469

It relates to this product which looked interesting at the time and still does.

http://www.123ignition.nl/products.php?brand=MG

Any distributor you get hold of now will be 30+ years old, where as these use electronics to reproduce the correct factory curve and simulate 16 different models in each (mini + MG) so there's plenty of fine tuning possibilities.

Hops this helps.
<MARK>
http://freespace.virgin.net/marka.hester/RaceStuff.htm
Mark Hester

Thanks Doug and Mark - most useful assistance. And Mark, I enjoyed following the informative links on your website.

Joe
Joe Gates

This thread was discussed between 07/09/2005 and 08/09/2005

MG MGA index

This thread is from the archive. The Live MG MGA BBS is active now.