borg230rover
|
| posted on 8/6/13 at 01:46 PM |
|
|
Spark Plugs overheating
Hi
As a general rule, if spark plugs are over heating will it effect the maximum RPM.
I have a BEC (R1 Turbo) before the upgrade of the turbo it used to rev right up to around 11500/12000rpm however since the turbo has been fitted the
most Rpm I seem to be able to get is 10600 that's max sometimes slightly less. I think I have narrowed it down to it being the spark plugs as I
have left the standard ones in and narrowed the gap to stop spark blow.
The reason I am assuming its the plugs is because, it reaches different maximum Rpm's all the time and is not consistent it ranges from 10050rpm
up to 10600rpm,it is perfectly fine at the low rev range and starts fine, so I am assuming when Im on full throttle and max boost the combustion
camber is obviously at its hottest in turn making the plug at its hottest and instead of it sparking its probably pre-igniting or its not sparking at
all due to the heat.
Another reason I think the spark plugs are faulty from heat issues is because when the engine is on tick over and I disconnect HT leads (1 at a time)
2 of them make next to no difference in the way the engine is running, 1 of them makes a big difference, and 1 of them stools the engine.
Thanks from all help.
Just remember "There is always going to be someone quicker than you"
|
|
|
|
|
snapper
|
| posted on 8/6/13 at 03:12 PM |
|
|
You can run low temp plugs to see if it helps
The other problem can be the turbo restricting flow at high rpm
What does your boost gauge do?
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
|
|
|
dave_424
|
| posted on 8/6/13 at 04:10 PM |
|
|
Like snapper says, if your manifold is restrictive then that can stop your engine revving fully.
What are your spark plugs at the moment? CR10EK plugs are a good choice for a turbo bike engine, gapped to .018"
How are you controlling fuel and spark? If your ECU pulling massive timing at the high end of the rev range?
Do you have a wideband? getting lean/rich at the higher end of the rev range?
What turbo are you running?
Really need more information to solve the problem
|
|
|
mark chandler
|
| posted on 8/6/13 at 04:27 PM |
|
|
Cannot see the plugs holding you back TBH, I would look at fuelling and sparks first.
Do the plugs show signs of overheating, molten ceramic etc.
My turbo blade is affected with any lead pulled, maybe you have head gasket issues, have you packed out to lower the compression with 2 gaskets? My
car is happy with stock compression running on optimax with 7psi boost.
[Edited on 8/6/13 by mark chandler]
|
|
|
borg230rover
|
| posted on 8/6/13 at 04:30 PM |
|
|
I have some cooler plugs on order to try, the whole engine including manifold was lifted straight out of a bike that was running spot on, manifold has
remained the same, turbo etc original built and setup by holeshot racing including restricted timing, the exhaust has had to be restricted due to over
boosting and even with boost controller it was not controlling the over boost enough, I have wide band fitted air fuel is good, even before the
exhaust had restrictor placed in it it would still not fully rev so it's not that.
Just remember "There is always going to be someone quicker than you"
|
|
|
borg230rover
|
| posted on 8/6/13 at 04:33 PM |
|
|
Hi mark, I wouldn't mind meeting up one day for you to cast an eye over as I only live Basingstoke and work in Tadley.
Just remember "There is always going to be someone quicker than you"
|
|
|
mark chandler
|
| posted on 8/6/13 at 04:36 PM |
|
|
I run a BOV to protect against over boost, I have also set a max boost cut in megasquirt at 11psi (from memory).
Restricting the exhaust sounds like a terrible bodge to address an over boost issue 
|
|
|
dave_424
|
| posted on 8/6/13 at 04:37 PM |
|
|
You say that when you take off one of the HT leads, there is no noticeable change? sounds like an ignition problem, has the rev limit been reduced?
will it rev out all the way out when sitting at idle, slowly roll into the throttle so you aren't making a load of boost that could affect it.
|
|
|
mark chandler
|
| posted on 8/6/13 at 04:37 PM |
|
|
You can pop over now if you like, car is not MOT'd so no chance of a run out, maybe next month.
|
|
|
borg230rover
|
| posted on 8/6/13 at 05:01 PM |
|
|
Had a couple of drinks at bar bee so can't today, maybe next weekend.
As for the restrictive exhaust, and megasquirt its carb'd, so mega squirt no good, I have been told to either restrict exhaust gas flow via
exhaust or fit a smaller air intake filter, so may mistake I have fitted small air filter not restrictor in the exhaust.
Just remember "There is always going to be someone quicker than you"
|
|
|
mark chandler
|
| posted on 8/6/13 at 05:15 PM |
|
|
Hummm
Restrict exhaust, restrict inlet however you look at it you put on a turbo to increase flow through the engine, by restricting the engine will be
making power at the piston and losing it trying to get air in or force it out, net result less at the wheels and everything getting hotter and working
harder...
You need a much better strategy, a decent external waste gate should solve things, are you using the turbo's inbuilt item?
Cheap and easy is a BOV which you preload to blow off when it see's excess boost and just waste the air in these conditions, mine cost £30
second hand a few years ago.
|
|
|
dave_424
|
| posted on 8/6/13 at 05:21 PM |
|
|
If you are experiencing boost creep, then your wastegate isn't big enough, go external or open up your existing wastegate port.
Don't go with the BOV to act as a pressure relief valve, this will over spin your turbo and can kill it.
you can put a restricting ring in the exhaust if needed, this increases back pressure which will slow the turbo down, but more heat is introduced in
the engine/manifold. This has to be done on the supras when a larger exhaust is used, the reduction in back pressure allows the turbo to make more
boost so a restriction is added to the system.
Don't restrict the inlet side of the turbo.
|
|
|
borg230rover
|
| posted on 8/6/13 at 06:46 PM |
|
|
I'm not sure how a Bov would even work to release pressure anyway, I thought that they release all the pressure on when boost drops off.
Just remember "There is always going to be someone quicker than you"
|
|
|
mark chandler
|
| posted on 8/6/13 at 08:06 PM |
|
|
My BOV can operate in two modes, the piston is sprung loaded and shimmed so if boost in excess of 12 psi hits it the piston lifts and releases air.
It also has a vacuum connection which pulls the piston up, it is plumbed between the butterfly and cylinder head so when I throttle down the vacuum
pulls up the piston and spills air, this stops the turbo stalling so you do not get lag between gear changes.
My turbo is a variable vane so no waste gate here.
I believe you need to sort out your waste gate and actuator before going any further.
Regards Mark
|
|
|
borg230rover
|
| posted on 8/6/13 at 08:18 PM |
|
|
The waste gate that is built into the turbo has been the same from when installed originally on the bike by jack at Holeshot Racing, you probably know
of him, pretty much the god of turbo bikes. However all said and done the waste gate is not likely to effect the engine reaching maximum RPM, even
with a bigger air filter than standard one it was not reaching make rpm. The engine boosts up to 14psi no problem and will sit there. The sparks seem
the only weak link.
Just remember "There is always going to be someone quicker than you"
|
|
|
borg230rover
|
| posted on 8/6/13 at 08:20 PM |
|
|
The waste gate that is built into the turbo has been the same from when installed originally on the bike by jack at Holeshot Racing, you probably know
of him, pretty much the god of turbo bikes. However all said and done the waste gate is not likely to effect the engine reaching maximum RPM, even
with a bigger air filter than standard one it was not reaching make rpm. The engine boosts up to 14psi no problem and will sit there. The sparks seem
the only weak link.
Just remember "There is always going to be someone quicker than you"
|
|
|
dave_424
|
| posted on 8/6/13 at 08:28 PM |
|
|
This is true, but with the higher load when the engine is in a car when compared to a bike, it would seem that it would cause more exhaust gas flow.
Since you haven't been having issues with boost spike/creep, then why have you been trying to restrict flow through the turbo on both the inlet
and exhaust side? I must be missing something here but those two things don't go together...
So you are sure that fueling isn't doing anything strange like getting above 12:1 when on full boost at high RPM?, if you were experiencing
misfires or something wrong with the ignition system, you would typically see a false lean condition.
So what is your ignition set up? all stock igniton? boost retard controller?
Dave
|
|
|
borg230rover
|
| posted on 8/6/13 at 09:21 PM |
|
|
Hi,
When I had the exhaust made for the car application only from turbo back! The guy said that I needed a bigger air filter, at the time I had original
bike one on there, it was only from fitting the bigger one supplied by the exhaust fitter that I had problems controlling the boost. I then changed
the filter back to the original, I have never restricted the exhaust.
I have timing retard 3 degrees I think, it was set by Jack when building the engine.
I have a wide band fitted it, shows good AFR when on boost and high RPM it's about 10.5.
Just remember "There is always going to be someone quicker than you"
|
|
|
mark chandler
|
| posted on 8/6/13 at 10:19 PM |
|
|
At 12psi you must be getting 250bhp, apart from the rev issue does feel like a 250 BHP car?
Mine is 201 BHP from the dyno, and it feels it, spins the rear wheels up on acceleration in the first 3 gears etc.
Did you ride the bike before transplanting the engine? What's different apart from the exhaust, fuel pump, fuel lines & exhaust?
Your first post indicates that something is not correct as knocking off leads has mixed effects upon the idle, did the engine sit around before
installation as a good carb clean and balance may in order.
Bike engines are very sensitive to plugs, in a bike you cannot hold full power for long so a 250 BHP bike may never have been ridden to the point that
you are seeing the issue as low gears could through you off the back, high gears unless you are pushing 150mph you will not be hitting the red line,
just enjoying the power in the high gears.
|
|
|
borg230rover
|
| posted on 9/6/13 at 07:20 AM |
|
|
It does feel like its got 250 and will spin the rear up, I do have toyo 888 so they are pretty sticky, I had thought about the carbs already and as
such got centre off to nrp carbs for cleaning, setup etc they said they look like a very low mileage set of carbs on very good order. The engine
didn't sit around at all in was installed into the car with in about 3 days of being built, I have had it on the rolling road at pdq in slough
it was just over 200bhp at the wheels but at the time was running rich as it had 144 jets, it now has 125 jets but since having them fitted it has not
been on the rollers, I was expect it to be up around 250/270bhp going by other r1 same model engines.
Just remember "There is always going to be someone quicker than you"
|
|
|
borg230rover
|
| posted on 9/6/13 at 12:27 PM |
|
|
I understand what you are saying about the power in the bike with lower gears throwing you off the back and top speed, its a good point.
Just remember "There is always going to be someone quicker than you"
|
|
|
matt_gsxr
|
| posted on 10/6/13 at 10:11 PM |
|
|
Why not give Holeshot a call. As you say they are the experts and will know your install better than anyone.
But to throw in an opinion...
From my simple understanding you don't really want to be controlling boost creep using restrictive exhaust or restrictive filter. Although those
two can work its not a very elegant solution. Restrictive filter may alter fueling depending on whether the filter is new, wet or clean, restricting
the exhaust may well delay spin-up.
I struggled with boost creep and ported my wastegate (internal wastegate on a td04-16T), not a difficult job.
I don't think the idle issue is linked with the high RPM issue. Surely your plugs won't be too hot under idling conditions. To me it
sounds more like you have a carb balance issue, which should be easily tweaked.
Have you done a high power plug chop?
If you think you need a cooler plug then give it a go but on turbo suzuki's (below 1atm) most folk go with 9's.
Matt
|
|
|
borg230rover
|
| posted on 10/6/13 at 10:34 PM |
|
|
Hi
What's a plug chop, I am a little confused about what people are talking about now they are on about porting waste gates, getting external waste
gates, using BOV, tick over speed..... I just wanted to know whether plugs getting hot can cause the engine to not reach max RPM.
Just remember "There is always going to be someone quicker than you"
|
|
|
dave_424
|
| posted on 10/6/13 at 10:40 PM |
|
|
quote:
Originally posted by borg230rover
Hi
What's a plug chop, I am a little confused about what people are talking about now they are on about porting waste gates, getting external waste
gates, using BOV, tick over speed..... I just wanted to know whether plugs getting hot can cause the engine to not reach max RPM.
Pretty much no. What happens as you reach that high RPM wall? is it very smooth and you kind of creep up on a certain RPM you can't pass, or can
you feel miss firing, jerkyness etc?
What plugs to you have?
Give holeshot a ring and see what they say.
|
|
|
borg230rover
|
| posted on 11/6/13 at 05:39 AM |
|
|
I have tried holeshot already, and checked everything Kack suggested. Whether I'm sat still, driving normal, or giving it the beans it still
does not change, when I get to 10000 roughly it's like I'm hitting the limiter it's differcult to put into words but its like the
engine bouncing ding ding ding like its hit max rev but at 10000 it should still have another 2000 in it.
Just remember "There is always going to be someone quicker than you"
|
|
|
