Overfueling -> Bore Wash -> Blow By -> Crankcase Pressurisati

[tom_m 0]

thanks for the feedback. I can see the benefit od a split pattern spray when you are injecting directly into the inlet, but I can't see the difference it would make injecting into a throttle body.

 

Anyone care to explain ?

 

I'll do some research regarding the high powered 8vs on here..

 

saveloy is saying you won't be seeing any benefits from the split spray and might even be losing out because of it. but i tend to agree with sandy, spray pattern at that point in the inlet is debatable. its not like they are flowing enough to be dribbling fuel

[smckeown 1]

Your plugs tell the full story really. They are richer than a Russian football club owner.

 

I'm not sure running rich can be attributed to the injectors being the wrong type. My thinking is that during the original mapping the AFR showed all was good. Surely if the injectors were the wrong type (if thats possible with TBs) then it would have showed up there ?

 

So my thinking is that if all was well during the first mapping, and things have gone downhill since just after the 2nd mapping that either:

 

1 - The more wild cam and same fuel map has made it run rich (as there is less air but same fuel low&mid range)

2 - The temp sensor has indeed packed in.

3 - An injector has failed and is spraying more than when it was tested or since mapped

 

If only I had invested in the lambda sensor and display earlier I could have detected such a problem earlier.

 

I'm tempted (in the interest of science) to test the injectoir flowws. The new o'rings have arrived so I can do this when i'm at home tomorrow

 

I can also test the water temp by putting the rad back on and starting her up, then logging the ECU data (or filming it)

 

That might give us more information to go on

 

I have the VEMS arriving next week, but it will be at des' place before I can fit it

 

Thanks all for the debate, it's been an interesting area to learn more about

Edited December 14, 2006 by smckeown

[Grim.Badger 15]

Going back to your other post, are you sure you're not leaking oil because of your petrol contamination?

I seem to remember you're already using fairly low viscosity oil so if it's being thinned by petrol I'd expect the seals to really struggle.

How much petrol is in the oil? Have you still got any of the stuff you removed after running it? Can you ignite the fumes?

When mine ran rich the oil (15w40) would come out like water when I changed it, and I had fairly mild contamination. I'm also thinking that might have killed my rings because ever since then the car has been burning increasing amounts of oil, plus it appears to have been the cause for the silicon sealant to be stripped from the sump spacer which caused the oil pump to clog with strings of sealant

I hope yours isn't trashed considering you've hardly had the chance to drive the car.

[B1ack_Mi16 67]

Also one other thing, if your fuel-map is all over the place, it might kill torque.

So maybe the "new camshaft" ain't as bad as first thought anyway?

[smckeown 1]

Also one other thing, if your fuel-map is all over the place, it might kill torque.

So maybe the "new camshaft" ain't as bad as first thought anyway?

 

yes I have thought along those lines recently. Such a dilema, if the new build revs better then the current cam may actually be a better choice. Especially if the new smaller diameter exhaust improves low range torque.

 

Before the forum trolls start, the following includes no digs, just thinking! so sod off!

 

I read an interesting quote last night regarding puma commenting on maxi's engine and a reference to changing to a wilder cam. He said that as the engine was currently making only 70% of max torque at 3k revs that a wilder cam is not suitable. On my old cam I was making 80% max torque at 3k, so maybe there is/was a possibility that the wilder cam would benefit top end.

 

It all comes down to why torque was falling off so quick. If the torque would have fell of low slower, it would have made a lot more top end power (I have played with the graphs ) The reasons i know about could include:

 

1 - The rings were not sealing from the beginning, and crank case pressure was already an issue

2 - Head was not flowing enough for top end (Puma has contradicted himself in this area on the posts here, in 1 post he says adding forged pistons, PT28 cam and raisng compression to 11.75 would provide much more power..at hight revs obviously; in another he said the bottom/head combination was never meant to rev)..so who knows!

3 - Heavier pistons not ideal ? i'm sure all the high powered and revving 8v have had forged or mi16 pistons...i'm just researching this now.

4 - Not enough compression - i believe this has effect on top end torque

 

So i'm in a quandry as to whether the rebuild should incude a different head or keep the puma one, whethe rI should hold on to current and new cam (I have both currently) and whether I should go for a lighter and more complete balanced bottom this time. I must say though, there are some excellent posts in the archive on these matters, it's all very interesting.

Edited December 14, 2006 by smckeown

[Batfink 201]

sometimes its best not to speculate and just get the car to someone who knows what they are taking about as without examining the engine its impossible to guess or reliably work out what is wrong.

 

Why was the fueling etc not changed when the new cam was put in? I would have thought any significant change in engine spec would need as least a chech to see whether the fueling needs alteration.

 

Am interested to see the results from Des Dev next week. Fingers crossed there is not too much damage and the car can be fixed and sorted so we can see what the new spec changes.

[smckeown 1]

sometimes its best not to speculate and just get the car to someone who knows what they are taking about as without examining the engine its impossible to guess or reliably work out what is wrong.

 

Agreed, but it's still makes for an interesting discussion

 

Why was the fueling etc not changed when the new cam was put in? I would have thought any significant change in engine spec would need as least a check to see whether the fueling needs alteration.

 

I remember mikeanics saying at the time that fueling would not need to be changed. I specifically informed him beforehand of the cam change (and the specs). I assumed he knew what he was talking about, having had such good feedback etc.

 

Am interested to see the results from Des Dev next week. Fingers crossed there is not too much damage and the car can be fixed and sorted so we can see what the new spec changes.

 

I'm expecting the worst, if it has to come apart to be checked, then it's the idea time to change things, like compression, mi16 liners and pistons etc....but yeah we'll see what he things.

[johnrobertgordon 0]

Before the forum trolls start.

 

LOL

 

You said Troll.

[Robsbc 0 1 Cars]

I'm expecting the worst, if it has to come apart to be checked, then it's the idea time to change things, like compression, mi16 liners and pistons etc....but yeah we'll see what he things.

 

What a mess Sean to say it blunlty!

 

You certianly know how to chuck money down the drain...Basically you might as well start from the drawing board again from what your saying.

 

Eob

[smckeown 1]

What a mess Sean to say it blunlty!

 

You certianly know how to chuck money down the drain...Basically you might as well start from the drawing board again from what your saying.

 

Other than laugh what else can you do eh ? thorwing money away ? erm no chance!

[Rob Thomson 6]

Surely a lightened and balanced bottom end won't affect the torque curve, and neither will lighter pistons. If the bottom end can rev high enough to exploit the cam and head that's really all that matters. If you're making peak power at 6.5k and can rev the engine beyond that then you're barking up the wrong tree. On the other hand, if peak power was at the limiter and power was still increasing then a bottom end upgrade would be useful. But that's not the case here.

 

I'm amazed about the remap comments. Clearly a different cam is going to affect how much air (and thus fuel) is required by the engine across the rev range. A peaky cam is going to require more fuel at high rpm than a milder cam, that's just obvious and I can't believe the fuel map wasn't changed to suit.

[smckeown 1]

Surely a lightened and balanced bottom end won't affect the torque curve, and neither will lighter pistons.

 

If the bottom end can rev high enough to exploit the cam and head that's really all that matters. If you're making peak power at 6.5k and can rev the engine beyond that then you're barking up the wrong tree.

 

From my limited research isn't it the case a lighter set of pistons enables you to gain higher revs, or revs better ? Obviously my current engine has never reved well, there has to be a reason ? Yes i'm extatic with the mid range; before anyone pipes up as before

 

I'm amazed about the remap comments. Clearly a different cam is going to affect how much air (and thus fuel) is required by the engine across the rev range. A peaky cam is going to require more fuel at high rpm than a milder cam, that's just obvious and I can't believe the fuel map wasn't changed to suit.

 

I'm going to call him tomorrow when i'm back in the country to discuss, see what he says.

[Rob Thomson 6]

Can I also say, Sean, that you seem to put a lot of trust in a lot of people...

 

I'm currently having a TU engine built by Dave Baker, and I have a lot of faith in the bloke. Certainly none of your problems have put me off in the slightest; there really is nobody else who I'd want to build an engine.

 

But I don't have any faith at all in most motorsport specialists. One of my best mates runs a rally preparation company, and I let him look after my 106 for me. He's very, very good at fabrication and bolting stuff together in a hurry, but I never listen to his advice about anything technical because it's all heresay. I have an engineering degree (ok, it's Civil Eng) and can understand how things work. If someone offers me advice about something I'll use my own judgement as to whether that advice makes any sense. Nine times out of ten it doesn't. There's no way I'd trust anyone to run a car in for me... There's no way I'd let anyone who thinks that crankcase pressure and oil pressure are related even touch my car... Personally I think you should keep the list of people as short as you possibly can, because everyone's advice will contradict and you won't have a clue what to do next.

[James_m 0]

I think lighter pistons would have the same affect as a lighter flywheel, i.e, it would rev quicker if not higher.

The way i see it is, the reason it wont rev beyond 6.5krpm is because the head just does'nt flow well enough, the same reason why the standard car will barely rev beyond 6k, and an MI is still climbling past 7K

[Rob Thomson 6]

From my limited research isn't it the case a lighter set of pistons enables you to gain higher revs, or revs better ? Obviously my current engine has never reved well, there has to be a reason ? Yes i'm extatic with the mid range; before anyone pipes up as before

Yeah, of course lighter or stronger reciprocating components will rev higher, and lighter bits will spin up more easily, make the engine more responsive when you 'blip' it etc. But that doesn't affect how much power it develops 500rpm below the red-line. That's down to the head, cam, induction, exhaust, etc - and possibly in this case poor bore sealing for whatever reason.

[smckeown 1]

I'm currently having a TU engine built by Dave Baker, and I have a lot of faith in the bloke.

 

I was in the same position 18 months ago, I didnt want anyone else to build my engine. I still think he is a top class engine builder and have never said anything different, plus he's cheap..bonus!. Things didn't work out for us in many ways, personality had a lot to do with it. I can't take sh*t for no reason of anyone...anyway I digress. Good luck to him..genuinely

 

Can I also say, Sean, that you seem to put a lot of trust in a lot of people...

 

You can't compare apples with oranges. I'm in IT and know feck all about engines/cars. I always 'try' and keep my suppliers down to a minimum. Someone asked this question not long ago and I replied with why I have had to use different people, it's not been something i've gone out to do.

[johnrobertgordon 0]

I agree with the too many cooks theory. I would have stuck with one person and allowed a development curve with that same person. If you chose that person right in the first place you are going to end up with something good.

I have notice you seem to chop and change your ideas as to what you have read, you cant just read things then take it as gospel.

What are you actually trying to get out of your engine?

 

Oh and lighter flywheel and internals actually reduces torque. The lighter the flywheel the quicker it will spin up and also it will shed speed faster, a heavier one will take more effort/time to spin up but will carry more inertia (sp?).

[Rippthrough 98]

Lighter internals will increase torque under acceleration, because less of the engines power is being used to accelerate them. But, like a lightened flywheel, it's not going to make much difference in higher gears/loads, especially with the masses being little different compared to a lightened fly.

 

Your main problem here is the fuel map, if mike said you'd wouldn't need a the fuel map tweaking for a wilder camshaft then I wouldn't go anywhere near him next time, kinda weird as he usually gets good reviews, but that's plain wrong.

 

Sort that out first and then work from there, eliminate the problems one by one.

 

-Phillip

Edited December 14, 2006 by Rippthrough

[johnrobertgordon 0]

Sort that out first and then work from there, eliminate the problems one by one.

 

-Phillip

 

I agree, and dont change anything till you get your current spec running propperly and have had a good play with different settings. This should then highlight any weak areas and then you can make changes accordingly.

 

 

Oh and as for the lightened innards I agree with the sapping less power thing but Torque is the engines inertia, you cant have lots of inertia with out weight. A lighter flywheel will definately reduce torque.

[Rippthrough 98]

I agree, and dont change anything till you get your current spec running propperly and have had a good play with different settings. This should then highlight any weak areas and then you can make changes accordingly.

Oh and as for the lightened innards I agree with the sapping less power thing but Torque is the engines inertia, you cant have lots of inertia with out weight. A lighter flywheel will definately reduce torque.

 

no, torque is what an engine generates from burning fuel.

[johnrobertgordon 0]

Sorry, I forgot about the fuel I put in my Torque wrench.

 

In physics, torque can informally be thought of as "rotational force" or "angular force" which causes a change in rotational motion. This force is defined by linear force multiplied by a radius. The SI units for Torque are newton metres. In the U.S., foot-pounds force (ft·lbf) are also commonly encountered. The symbol for torque is τ, the Greek letter tau. The concept of torque, also called moment or couple, originated with the work of Archimedes on levers. The rotational analogues of force, mass, and acceleration are torque, moment of inertia, and angular acceleration respectively. The force applied to a lever, multiplied by its distance from the lever's fulcrum, is the torque. For example, a force of three newtons applied two metres from the fulcrum exerts the same torque as one newton applied six metres from the fulcrum. This assumes the force is in a direction at right angles to the straight lever.

[Rippthrough 98]

Sorry, I forgot about the fuel I put in my Torque wrench.

 

In physics, torque can informally be thought of as "rotational force" or "angular force" which causes a change in rotational motion. This force is defined by linear force multiplied by a radius. The SI units for Torque are newton metres. In the U.S., foot-pounds force (ft·lbf) are also commonly encountered. The symbol for torque is τ, the Greek letter tau. The concept of torque, also called moment or couple, originated with the work of Archimedes on levers. The rotational analogues of force, mass, and acceleration are torque, moment of inertia, and angular acceleration respectively. The force applied to a lever, multiplied by its distance from the lever's fulcrum, is the torque. For example, a force of three newtons applied two metres from the fulcrum exerts the same torque as one newton applied six metres from the fulcrum. This assumes the force is in a direction at right angles to the straight lever.

 

 

erm, yes you do, it's called food and you eat it before you turn the thing. this is going off topic, so if you want to run through this PM me.

[johnrobertgordon 0]

Yup sorry for being off topic.

[smckeown 1]

I agree with the too many cooks theory.

 

Jumping on the bandwagon are we john john?, this thread is turning out to be a 'I told you' so' i think you should have done it this way' thread. Talk about getting off topic and hindsight is a wonderful thing. Doesn't effect the discussion that is the title of the thread though does it ?

 

I would have stuck with one person and allowed a development curve with that same person.

 

You are obviously not reading the entire thread, I have explained WHY different people have been used.

 

If you chose that person right in the first place you are going to end up with something good.

 

So by that rational you think PumaRacing isn't the right company. I simply don't agree.

 

 

I have notice you seem to chop and change your ideas as to what you have read, you cant just read things then take it as gospel.

 

What are you actually trying to get out of your engine?

 

Now this is getting on my tits. I didn't provide an exact specification of the engine, look into the posts and you'll see the engine was designed and built by PR. So maybe that's a question for HIM not ME. Anyway he listed the exact purpose and thinking behind the build on this forum, so maybe you should do some research before making sarcastic posts. The discussion on this thread has turned to the issue regarding the quick tail off of the torque. The objectives going forward are to try and stop such a quick tail off is possible, and maximise the low down torque.

[johnrobertgordon 0]

My post was not ment as sarcastic.

 

I was simply trying to ask what it is you want from your engine or are you just bolting bits on and hoping its to your taste.

 

As for twisting my words into your despute with Puma Racing I feel that was a little harsh. I have never used him for any work so I would not care to comment, but from what I have heard and read on his site it all seems good, but like I say I have not seen any of his work and even if I had i am in no way qualified to judge.