mpbarrett Posted January 31, 2018 Report Share Posted January 31, 2018 I know a few people have fitted Megasquirt EFI systems to there Heralds and Spitfires. I am interested in what injectors you have used (ideally model and flow rates). I have got my MS3 system working on a 1500 engine in a Herald but feel the injectors are too big so want to change them and am interested in what others are using. Cheers mike Link to comment Share on other sites More sharing options...
Clive Posted January 31, 2018 Report Share Posted January 31, 2018 I think the common rule of thumb is to use injectors from a car that is similar power to what you expect. So something around 90-100bhp should be about right? A bit more certainly won't hurt, but I would avoid going too large. Remember flow will be affected by pressure too, so that is worth a thought. You could use a lower pressure regulator, that would have the same effect as smaller injectors. I am guessing the mapping is a bit sensitive,with injectors running at low duty rates. Link to comment Share on other sites More sharing options...
Darren Groves Posted January 31, 2018 Report Share Posted January 31, 2018 I used Bosch 0280155884 fuel injectors on my Herald, used on many Rovers, widely available and cheap to buy...I don’t think I paid any more than £7.00 each for any of them. When trying to find the flow rate, I did find various answers, but settled on the one in the attached image. Darren Link to comment Share on other sites More sharing options...
mpbarrett Posted January 31, 2018 Author Report Share Posted January 31, 2018 Clive you are right it is very sensitive to pulse width. I am using Bosch 747 injector at 200cc/min @3bar a bit big for a 1500 Triumph engine. If I use the default VE map it runs very rich using the default dwell time, if I reduce the dwell time I start to get a decent AFR reading. I can get it running ok with a reduced VE map (multiplying everything by 0.5). but then the VE map values are lower than what others have used, that's why I want to review the injector I have been using. All a bit of a long learning curve, but quite fun. Mike Link to comment Share on other sites More sharing options...
mpbarrett Posted January 31, 2018 Author Report Share Posted January 31, 2018 Darren thanks. I think those are ideal and cheap! Are you running a 1300 engine? There are a bit longer than the747 I am using and will run into the airbox I have built! Poor design.... cheers mike Link to comment Share on other sites More sharing options...
rogerguzzi Posted January 31, 2018 Report Share Posted January 31, 2018 36 minutes ago, Darren Groves said: I used Bosch 0280155884 fuel injectors on my Herald, used on many Rovers, widely available and cheap to buy...I don’t think I paid any more than £7.00 each for any of them. When trying to find the flow rate, I did find various answers, but settled on the one in the attached image. Darren Hello Mike I think those are the same injectors I use? and I use the same flow rate on a 1500 spitfire with ITB,s (Jenvey type but cheaper!) I will check tomorrow. At the moment I run a Triumph grind cam 25 65 65 25, semi ported head, 4 branch and about 9.5 to 1 compression ratio She did about 5,000 miles last year on these settings(sill not perfect but building a new engine so not adjusting any more for now!) Roger Link to comment Share on other sites More sharing options...
Clive Posted February 1, 2018 Report Share Posted February 1, 2018 Yes ,those injectors look about right for approx 110bhp at 3 bar and 80% duty. Are you running a wideband controller? I know ms3 is pretty advanced, and it should be able to autotune itself and modify the VE table itself? But smaller injectors would give better definition. Link to comment Share on other sites More sharing options...
rogerguzzi Posted February 1, 2018 Report Share Posted February 1, 2018 14 hours ago, rogerguzzi said: Hello Mike I think those are the same injectors I use? and I use the same flow rate on a 1500 spitfire with ITB,s (Jenvey type but cheaper!) I will check tomorrow. At the moment I run a Triumph grind cam 25 65 65 25, semi ported head, 4 branch and about 9.5 to 1 compression ratio She did about 5,000 miles last year on these settings(sill not perfect but building a new engine so not adjusting any more for now!) Roger Hello Mike Yes those are the ones I use there are lots on Fleabay Rover 200,s etc used set £20! If you keep looking you will find new cheap, I think I got a set for about £30 new! Roger ps note to self I must get one spare for tool kit! Link to comment Share on other sites More sharing options...
mpbarrett Posted February 1, 2018 Author Report Share Posted February 1, 2018 Thanks for the helpful replies. Didn't have a chance to play with the car today as the granddaughter was around with her mum (Libby, GT6, 10CR) making marmalade...... And taking Libby's ford focus for an MOT, not looking good as I found some holes in the sills.... I could reduce the pressure with my injectors (suggested by Nick) to reduce the flow rate or get some lower flow rate injectors. cheers Mike Link to comment Share on other sites More sharing options...
rogerguzzi Posted February 1, 2018 Report Share Posted February 1, 2018 3 minutes ago, mpbarrett said: Thanks for the helpful replies. Didn't have a chance to play with the car today as the granddaughter was around with her mum (Libby, GT6, 10CR) making marmalade...... And taking Libby's ford focus for an MOT, not looking good as I found some holes in the sills.... I could reduce the pressure with my injectors (suggested by Nick) to reduce the flow rate or get some lower flow rate injectors. cheers Mike Hello Mike I would get the ones we all have and run at 3 bar £20 Fleabay? Roger Link to comment Share on other sites More sharing options...
mpbarrett Posted February 1, 2018 Author Report Share Posted February 1, 2018 Roger agree. But I have made my own air box that is a close fit to the throttle bodies which mean I cant fit the longer injectors that you have used, without modifying the air box! Yep stupid design... However I have found some short low flow rate ones on ebay and have ordered those! mike Link to comment Share on other sites More sharing options...
Mjit Posted February 2, 2018 Report Share Posted February 2, 2018 On 1/31/2018 at 11:15 PM, rogerguzzi said: ...1500 spitfire with ITB,s (Jenvey type but cheaper!) Which ITB are you using out of interest? Link to comment Share on other sites More sharing options...
rogerguzzi Posted February 2, 2018 Report Share Posted February 2, 2018 5 hours ago, Mjit said: Which ITB are you using out of interest? Hello I think these are the ones and they come with injector feeds they are extra on Jenvey! and connector link and they have seals on shafts and take standard Rover/MG TPS sensor(cheap if you look on Fleabay) https://www.ebay.co.uk/itm/40mm-twin-throttle-bodies-race-car-kit-car-etc-DCOE-spacing/132420692102?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649 Roger Link to comment Share on other sites More sharing options...
mpbarrett Posted February 7, 2018 Author Report Share Posted February 7, 2018 fitted the new injectors (155 cc/min rather than 200cc/min) and reset the maps and she is much better. Drove her to the TSSC/CT meeting on Monday night. Yesterday drove about 30 miles with the auto tune running and she is great. Runs much better than she did on carbs. Still a little bit rich but will leave it rich while I play, saver than running too lean. Cant get the Bosch Idle valve working correctly, and think the driver on the board is faulty so have ordered a new one (TIP122). Booked in for an MOT next week so need to check over the mechanical bits! cheers mike Link to comment Share on other sites More sharing options...
mpbarrett Posted February 9, 2018 Author Report Share Posted February 9, 2018 Driven the Herald around with it doing auto tune and seems to be running nicely (slightly rich but am happy while I play with it). Sorted the idle valve, faulty TIP122 on the board changed it out and ran it on the simulator while looking at the signals, all working well. Tried it on the car and its great. I realised that I have the valve round the wrong way (but don't think it matters) what it means is that I can adjust how much the valve is open when it powered off. There is a small allen key bolt in the end of the, valve this can be adjusted to set the airflow when the valve is off. Getting there and enjoying it! mike Link to comment Share on other sites More sharing options...
Gully Posted February 9, 2018 Report Share Posted February 9, 2018 Great to hear good progress and a success story! Well done, Gully Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now