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Posted: Thu Sep 04, 2008 5:43 am
by stevemgbgt
after much effort,experimentation,research etc I have finally got my 67bgt running on megasquirt.I am using a version3 with msnexxtra controlling fuel and spark.I used the SU inlet manifold and made an aluminium plenum chamber(sealed) with 2 SU rampipes leading into the inlet ports.Ifitted two jagaur XJ64.2 injectors firing into the rampipes and used a modified fuel rail off the same car to supply the fuel and the same cars pressure regulator and an external high pressure pump and return feed to the standard MGB tank.I used a throttle body off a Ford(escort I think)as it has a handy air bleed screw to fine tune the idle,connected to some air trunking and a K n N air filter.Triggerwheels supplied a 36-1 wheel and a VR sensor and a Ford wasted spark coil pack.Using Megalogviewer and a Techedge wideband sensor and controller I have been mapping it whilst driving and have to date covered approx 600miles with it getting better as I refined the mapping.Things such as the warmup enrichment and acceleration enrichment are still being fine tuned and as I am running in the rebuilt engine have only been to 70mph but it seems to be at least as good in performance terms as it was originally (possibly better but it is so long that I drove it I may have forgotten how good/bad it really was).I would submit some pictures but I am embarrased by my agricultural workmanship and am not entirely sure how to do it on this site as I am not too computer literate.

Re: 1967mgbgt1800

Posted: Sat Sep 12, 2009 10:04 am
by RSS
Fixin' to do the same thing on a '73 roadster. I've gotta decide which way to go for the TBs - use an old set of HIFs I have on hand, or go for something more sophisticated and use motorcycle TBs. Got both on hand, just need to decide which way to go. (HIF route is easier, and looks more "stock" but I like the sophistication of the motorcycle TBs and associated linkage and TPS.)

As for your "agricultural workmanship" (love the term!), I wouldn't worry about it. Your car is what, 43 years old? Post pics. :D

When you post an entry or reply here, look down below. You'll see a couple of tabs - one is labeled, "Options" and the other is labeled, "Upload attachment". Clicking on the attachment tab gives you the chance to locate a file on your local PC (using the "Browse..." button) and upload it. That lets you post one pic.

Another way is to have your pics hosted on Photobucket or the like. Use "img" code to post several pictures. For example, the picture below was posted using the following code: {IMG} ... s.jpg{/IMG} - where the { and } get replaced by the " [ " and " ] " characters.


Re: 1967mgbgt1800

Posted: Mon Sep 14, 2009 3:45 am
by stevemgbgt
Apologising for any errors or omissions this is my observations on Megasquirt/MGB1800.After 23 years of ownership the engine was worn out so whilst rebuilding it I had the great idea to extend my hobby into EFI.I bought MS because it was cheap,thinking if it did not work I would have wasted the least amount of money.I knew nothing of the forums at the time and bought it from a vendor with a very poor reputation.My experience with this vendor were nothing but excellent with speedy telephone and email advice(I have since bought a 2nd system from the same vendor for my Rover V8 MGB roadster with the same levels of service.Indeed when after 18months and 10,000 miles a coil driver failed on my original MS a phone call and a 3 day turnaround repair under warranty reinforced my good opinion)Following several scrapyard visits I decided to try to copy a manufacturers system for free with a single throttle boby and plenum.Using hand tools and A mig welder produced a working but ugly system.Due to inexperience I worked out that I would need injectors capable of supplying fuel for 20mpg which turned out to be too small with 100%duty at 4000rpm.Approx 7000miles of thought later I made a manifold with 4 injectors using a Y shaped heater pipe off a classic Triumph and a larger throttle.This larger throttle was soon junked as the map was 100% practically as soon as you touched the accelerator and it was almost undriveable.The design allowed 5500 rpm with 80% duty but loww speed(up to 2500rpm)response was poor and acceleration was full of flat spots at low speed and slow throttle roll on was very poor.Suspectiong low air speed/poor atomisation due to the much larger inlet manifold volume I made some small rampipes which I fitted in the plenum at the entrance to each intake runner.This helped tremendously but still was not right as thhe flat spots were lee noticeable but were still there.I tried every combination of AE this MS1 with the extra code allowed,some were better than others but none were spot on.This led to the latest (and possibly last:thoughts???? turbo?????) plenum and manifold.As my skills were insufficient I enlisted the help of a friend who built a new plenum with bigger ram pipes and modded the inlet manifold to take 4 injectors.The transformation is incredible with the engine now smoother and more responsive throughout the entire range of rpm and throttle positions.
ran out of attachments will try another post with rest.

Re: 1967mgbgt1800

Posted: Mon Sep 14, 2009 3:57 am
by stevemgbgt
Last two if you are still interested
On a different topic my V8 rover was already EFI and when the original Lucas 4C ECU died I ordered a wasted spark MS1 V3 ecu with the extra code,spent a weekend removing the redundant MAF sensor and rewiring the TPS and new MAT sensor,mounted the trigger wheel and fired up straight away.Less than 100 miles driving with TS and MLV and it runs better than it ever did and does 35mpg at 70ish mph

Re: 1967mgbgt1800

Posted: Mon Sep 14, 2009 4:01 am
by stevemgbgt
Sorry to run on and on but here are 3 more

Re: 1967mgbgt1800

Posted: Mon Sep 14, 2009 11:17 am
by RSS
Interesting evolution on the intake side there. I like the throttle plate setup, actually. Makes the linkage a lot simpler....

This is good info.

Re: 1967mgbgt1800

Posted: Sat Oct 14, 2017 12:39 pm
by NamVet66
I am going to start down the MS efi road on my '66 MGB Roadster this winter. I have a set of Mikuni throttle bodies complete with injectors that I believe will give me a good start. I may be asking some or maybe LOT'S of questions as I proceed. By the way, the build did not look agricultural just a good amateur build. If it works, it is good; if it works well, it is great!
Jim Hewitt