SR3 hot start issue
Discussion
I have just started to look after an SR3 for a friend who has only had it a few months.
We took it to track and did a few sessions and all was fine but after the third session the car wouldn't start and it sounded like a flat battery so we connected the booster box to the jump point and nothing, it sounded the same.
Fearing the worst we loaded it back into the trailer and took it back to the workshop.
The next day we rolled it out, I tried to start it and behold it fired into life with no horrible noises, checked the dry sump tank and oil was being pumped around the system and looked fine with no metal in it. (It did seem a little high)
Being a motorcycle mechanic I am wondering if the starter motor over heated as it's not protected from the exhaust pipe or the battery leads or battery got cooked.
Has anyone else had a similar fault and if so what caused it?
By the way it's an SR3 with the 1500cc conversion and a dry sump kit.
Any help would be great
We took it to track and did a few sessions and all was fine but after the third session the car wouldn't start and it sounded like a flat battery so we connected the booster box to the jump point and nothing, it sounded the same.
Fearing the worst we loaded it back into the trailer and took it back to the workshop.
The next day we rolled it out, I tried to start it and behold it fired into life with no horrible noises, checked the dry sump tank and oil was being pumped around the system and looked fine with no metal in it. (It did seem a little high)
Being a motorcycle mechanic I am wondering if the starter motor over heated as it's not protected from the exhaust pipe or the battery leads or battery got cooked.
Has anyone else had a similar fault and if so what caused it?
By the way it's an SR3 with the 1500cc conversion and a dry sump kit.
Any help would be great
TADTS...
Solution is 24v starting. The easiest way is to buy another battery, mount it in the passenger area somewhere ( with a made for the job bracket). Run a battery lead from the starter side of the solenoid to the negative terminal of the secondary battery then run another battery lead from the positive terminal to the starter. Make sure you can get charger leads on to the bat or connect some fly leads before you fit it if you are going to hide it. A charged battery will last for a few months as a starter so if you charge it between events you will have no problems
S
Solution is 24v starting. The easiest way is to buy another battery, mount it in the passenger area somewhere ( with a made for the job bracket). Run a battery lead from the starter side of the solenoid to the negative terminal of the secondary battery then run another battery lead from the positive terminal to the starter. Make sure you can get charger leads on to the bat or connect some fly leads before you fit it if you are going to hide it. A charged battery will last for a few months as a starter so if you charge it between events you will have no problems
S
Have a look at this thread (beginning and end) for a powerful 18V low cost, high quality and super low weight solution for your problem:
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
PM me for detailed info.
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
PM me for detailed info.
Yep!
That's pretty common with 1500s. When they are cold piston sealing clearances are pretty slack and so the engine turns over easily (depending on the ECU in use you may need to turn the crankshaft over 360 or 720 deg before the spark is engaged) and hey presto, it starts. When the engine is hot the clearances close up and the the effective high CR makes it difficult to turn the engine over to 1 - engage the spark 2 - generate enough momentum to bring several cylinders to sparking point.
The answer is as Simon says, 24v starting (or, if like Babak you're in Oz, 18v).
Just remember that you will need a late model starter (identified by a green label) to run 24v reliably and of course remember to charge the 2nd battery every few weeks.
I've also found that 1500s (esp but not uniquely on carbs) have a tendency to wet their (standard NGK) plugs if they don't start quickly and once wetted the engine never seems to start and run well (even blow torching the plugs doesn't seem to restore them). I've found that the only solution is to change the plugs or switch to Iridium.
That's pretty common with 1500s. When they are cold piston sealing clearances are pretty slack and so the engine turns over easily (depending on the ECU in use you may need to turn the crankshaft over 360 or 720 deg before the spark is engaged) and hey presto, it starts. When the engine is hot the clearances close up and the the effective high CR makes it difficult to turn the engine over to 1 - engage the spark 2 - generate enough momentum to bring several cylinders to sparking point.
The answer is as Simon says, 24v starting (or, if like Babak you're in Oz, 18v).
Just remember that you will need a late model starter (identified by a green label) to run 24v reliably and of course remember to charge the 2nd battery every few weeks.
I've also found that 1500s (esp but not uniquely on carbs) have a tendency to wet their (standard NGK) plugs if they don't start quickly and once wetted the engine never seems to start and run well (even blow torching the plugs doesn't seem to restore them). I've found that the only solution is to change the plugs or switch to Iridium.
I might be shooting in the dark here, but when starting a hot SR3, it really hates it if you open the throttle and it doesn't want to fire up. Also opening the throttle lets more airy-stuff into the cylinder which when running 12v starting, stops the uppy-downy bits in their tracks. So it seems to me that on 12v starting, it's even more important to keep well off the throttle.
Bert
Bert
Thanks again guys,
this has all been very helpful & we are now looking into 24v starting but I don't think the whopping price of the original start/charge kit can be justified so it will be a stand alone battery under the seat with a couple of extra tags coming off so it can be charged after each event.
It was defo a battery or starter motor fault as the engine wouldn't turn over at all, it wasn't that he had flooded it.
Another quick question for the guys in the know: This particular SR3 has a small black box fitted on the L/H side near the kill switch, it says "gear control" ??? Is this a flat shifter interface? if it is it don't work
I've gotta get a wiggle on as it's being used at Cadwell near the end of the month.
Once again thank you all for all the advice
Mark
this has all been very helpful & we are now looking into 24v starting but I don't think the whopping price of the original start/charge kit can be justified so it will be a stand alone battery under the seat with a couple of extra tags coming off so it can be charged after each event.
It was defo a battery or starter motor fault as the engine wouldn't turn over at all, it wasn't that he had flooded it.
Another quick question for the guys in the know: This particular SR3 has a small black box fitted on the L/H side near the kill switch, it says "gear control" ??? Is this a flat shifter interface? if it is it don't work
I've gotta get a wiggle on as it's being used at Cadwell near the end of the month.
Once again thank you all for all the advice
Mark
MotorGuru said:
Another quick question for the guys in the know: This particular SR3 has a small black box fitted on the L/H side near the kill switch, it says "gear control" ??? Is this a flat shifter interface? if it is it don't work
Mark
If that's what it says that's probably what it is!Mark
Has the car got paddles or a conventional gear lever?
How does one change gear?
The way a flatshifter type system normally works is a load sensor in the gear linkage (most likely at the gearbox end) which sends a + or - signal to the electronic "Black Box" which works out whether it's an upshift or downshift that's been called. It then either cuts the spark for a pre-determined time for an upshift or for a downshift sends a signal to the "Vacuum Black Box" which adds a throttle blip by sending a vacuum pulse to a blipper pot attached to the throttle quadrant. Can you see the other bits that one would expect with a flatshift type system - the in-line load sensor, the second "Vacuum Black Box" with vacuum pipe(s) and an electrical signal wire from the first electonic "Black Box" and a blipper pot on the throttle quadrant? If you've got all the bits then there's no reason why it can't be got working. BTW is there a manufacturer's name on the box?
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