camming setting up help UPDATE!! - Saxperience

andymiller_VTR · 30th November 2009, 21:50

Ok so this is starting to give me a headache tbh

Ive fitted a piper 285 cam to my vtr. The car runs however very badly. It will idle....just but it runs badly.

If i bring the revs up too say 2k then put my foot down the car pops and pops and the revs dont go up at all. Its kinda like a misfire or like its over fueling.

Ive been playing about with the timing tonight. When the pulley is advanced it runs worse, when its set to retarded it runs worse. So ive left it in the middle. However i still get the problem

The valve clearances are set at 0.2 for inlet and 0.25 for exhaust which is what piper say to set it too. Tomorrow im going to open them more and see if it runs better.

Any idea what this could be guys ?? All the sensors are plugged in etc so i really have no idea

cheers.

Sparco_Tom · 30th November 2009, 21:53

did you use the correct method to setting the spacings? the cam needs to be retarded 3degrees iirc

Liam_ · 30th November 2009, 21:55

When you fitted the vernier pulley, I assume you did it in such a way that the middle of the adjustment (0 mark) is standard timing? If you don't have a DTI to set the timing to the lift at TDC for the cam, I'd leave it at standard timing and have someone adjust it on the rollers for you.

Did you follow the guide in the Haynes when doing the tappets? Can be quite hard to gauge when the right valve is on the rock, i.e fully open. A DTI sometimes makes it easier as it'll tell you when the valve is at its lowest point.

andymiller_VTR · 30th November 2009, 22:02

i have no idea what a DTI is tbh

Yes the centre of the vernier is standard timing. I think the valve clearances are set too tight actually. ill check them tomorrow. Is 0.2 and 0.25 sound about right ??

raunchz · 30th November 2009, 22:08

That's the spec piper recommend so I'd leave it at that - I hope your planning a remap as looking at the cam spec it'll need one which could account for it.

Set the timing up so full lift at 110 degrees and get a remap

andymiller_VTR · 30th November 2009, 22:10

i cant afford a remap just now its too expensive. I thought this cam was the same as the ph3 and could be made to run ??

The thing is when the clearances were open more when i first turned it on it ran so much better than when there set to the piper settings

raunchz · 30th November 2009, 22:19

I don't really know about how cars with less than 16v run with aftermarket run.

It's a 264degree cam, so will be very lumpy when on standard map and standard timing. If you set the timing and valve gaps properly, then it gives the place who map it a basis to tweak to get the best results.

Could get it plugged into diagnostics if you don't think it's running properly

andymiller_VTR · 30th November 2009, 22:26

do you think loosening the valve springs a bit would make any difference ??

Liam_ · 30th November 2009, 22:27

DTI is a dial gauge mate... from memory, this is how williams did mine:

Basically, your cam will have a lift at TDC figure on the spec sheet (or contact Piper for it). You position the DTI so it's reading off the inlet or exhaust valve for cylinder 1 (can't remember which, I think it's the exhaust valve but williamsvts will be able to confirm) and zero the reading on the gauge. You then turn the engine over and lock the flywheel at the front of the block so cylinder 1 is at TDC, then measure the lift on the valve. Adjust the timing via vernier until the valve lift matches that on the spec sheet. If I didn't have a DTI, I'd make sure it was at standard timing - 8V's tend to make good power there, so let the mapper/ tuner adjust it from there on the rollers.

A DTI is also useful for adjusting the tappets too, as say for instance: when no 3 exhaust is fully open, check and adjust x and y if necessary. If you position the DTI on no 3 exhaust valve, you can turn the engine over and the gauge will show when the valve is at it's highest point - fully open. As the valve goes down, the pointer on the gauge will be rotating one way, then when it's gone past it's highest point it'll switch and start rotating the other way. The valve will be fully open between the two.

You can do it by eye though - there's a good guide in the Haynes or here for it. Make sure the engine is cold, leave it overnight if you have to. You can either turn the engine over on the crank, or jack one side of the car up and rotate the wheel (with the car in 3rd gear). Turn the engine over until the right valve is fully open (or fully down looking into the head). The feeler gauge should be a light sliding fit, not too tight or too loose. Alter the angle at which you're sliding the feeler through to confirm. Remember, inlet valves are at the back, exhaust at the front. Cylinder 1 is at the gearbox end of the engine.

Your feeler gauges are definitely metric right? If you have no joy and you think the timing may be out, then I'd stick the standard pulley back on. Lock the flywheel at front, then lock the cam pulley. That cam should idle near enough like standard at std timing imo.

raunchz · 30th November 2009, 22:28

Quote:

Originally Posted by andymiller_VTR

do you think loosening the valve springs a bit would make any difference ??

Well I don't have a haynes manual to compare the standard clearances to Pipers.

Loosening them off will just make the car sound more 'tappety' IMO - Pipers spec doesn't sound 'close really

andymiller_VTR · 30th November 2009, 22:32

hold the phone here i think ive made a boo boo. I thought cylinder one was done from the timing belt side of the engine ??

Also i thought when the valve was fully open when the rocker is at fully height looking down into the head not down ??

Liam_ · 30th November 2009, 22:35

Quote:

Originally Posted by raunchz

Well I don't have a haynes manual to compare the standard clearances to Pipers.

Loosening them off will just make the car sound more 'tappety' IMO - Pipers spec doesn't sound 'close really

Std clearances are 0.20mm inlet, 0.40mm exhaust. Assuming Pipers are in the order inlet, exhaust respectively, you shouldn't need to adjust the tappets for the inlet - they are the same as std. Just adjust exhaust clearances to 0.25mm when the Haynes/ that guide says to adjust an exhaust valve (in the correct sequence).

raunchz · 30th November 2009, 22:35

Valve is fully open when the rockers pushed it completely down

cylinder 1 is by gearbox

andymiller_VTR · 30th November 2009, 22:36

i thought cylinder one was at the timing belt side so clearly ive made an arse of that lol.

I take it adjusting them again to piper settings in the right order would make a difference to how it runs ??

Liam_ · 30th November 2009, 22:36

Quote:

Originally Posted by andymiller_VTR

hold the phone here i think ive made a boo boo. I thought cylinder one was done from the timing belt side of the engine ??

Also i thought when the valve was fully open when the rocker is at fully height looking down into the head not down ??

The valves are opening down into the engine, so fully open is when they've been pushed the furthest down towards the piston.

Cylinder 1 is at the transmission end of the engine. Let the car cool down, adjust the tappets properly and hope you haven't broken anything.

Tappets make a huge difference - they will be way out at present, so valves are opening/ shutting at the wrong times. I only hope you've not warped the head or burned some valve seats!

andymiller_VTR · 30th November 2009, 22:44

aww thats explains it then

now i know what to do tomorrow then.

cheers guys

andymiller_VTR · 1st December 2009, 20:07

ok so ive setup thew valve clearances to the piper setting now 0.2 inlet and 0.25 engine and its slighty better but stil when i put my foot down it coughs then if i lift off its ok again.

Im going to try and change the exhaust to the standard 0.4 to see if that will make a difference.

Any ideas ??

Liam_ · 1st December 2009, 20:14

Should be fine with those valve clearances if Piper have specified them for that cam. Mine were set to 0.25mm inlet and exhaust with the PT40 and it was fine - albeit a little louder (tappy) than standard.

You sure the timing is right? If not, I'd swap the vernier for the original cam pulley, lock flywheel at front of block, lock std cam pulley - then you know 100% it's at standard timing.

andymiller_VTR · 1st December 2009, 20:19

im pretty sure the timing is right but not 100% tbh. That a job for the weekend i cant do the at night in the dark lol

The car runs ok though aslong as you dont put your foot down thats why im confused

andymiller_VTR · 1st December 2009, 20:43

fuck it a garage can fix it i dont know what im doing tbh.