HELP! noise after changing cams

TheHood

TGA think it's definitely a cam timing problem and according to the timing tool I have I'm doing it correctly, so that combined with what TGA described as "premature wear" to the bearing caps in the picture below leads me to suspect the cams may have a manufacturing error.

There was some scoring before, but in less than 500 miles I'd say it's doubled the amount the original cams caused in 40,000 miles (all bearing cap bolts tightened in a spiral pattern from the middle cap outwards to 10 Nm with a brand new certified torque wrench).

I freely admit I have next to no practical experience with these things and would be willing to hear if anyone that has any other explanation?

vocky

that doesn't look good, certainly it looks like the bearing has 'picked up'

I wonder if you have an oil pressure problem, that would account for the noisy lifters. A new oil pump might be an idea, but no guarantee that it's that, certainly worth changing oil and filter, maybe even some engine flush first.

I would have the bearings cleaned up (they are the head so replacement = new head) with some very, very fine emery cloth, at least 1000 grit

For info: Oil pumps are over £250 at the dealer but this one on ebay is £75 delivered, genuine part too.

http://cgi.ebay.co.uk/VX220-Oil-Pump-Z2 ... 286.c0.m14

vocky

I've just checked the bearings on my saab head, which has done a similar mileage, there are no visible scoring marks.

the fact you noticed some marks whilst removing the cams would point to a problem before you removed the cams.

TheHood

Engine flush was the first thing TGA tried as part of the service. :thumbup:

I may replace the oil pump, but I'm not convinced oil pressure is the only culprit- why would the cam swap cause the wear rate to increase so much given an oil pressure issue would have pre-existed? (BTW I was ultra paranoid about making sure the bearings were spotless before the swap)

These are the bearing surfaces on the exhaust side of the head; what do you think?

Would I be best talking to an engine re-builder about getting the bearings cleaned up, or is it something I could do myself with the right kit?

Oh sod it, is your lost foam head spoken for Vocky? 🙂

vocky

I would strongly advise to replace that head, for whatever reason it's suffered oil starvation and that amount of 'pick up' is not good 🙁

the top pic is how they should all look, just slight witness marking where the cam turns, but the other pics don't look very healthy at all 🙁

there was an engine on ebay which suffered a similar end, the bearings caps seemed to have melted only on the exhaust cam !

my lost foam head was sold weeks ago 🙁

nickb777 will have a spare head in the next few days / week or so, might be worth a pm ?

TheHood

Double arse 🙁

I've sent bickb777 a PM and clicked "buy it now" on that oil pump. :thumbup:

Another option I'm considering is admitting defeat and getting Courtnays to do a proper CS5.

Shame really; I enjoy working on the car and I'm not convinced I've done anything wrong, but evidently I'm shite at it!

Either that, or I've got a rouge set of cams - ComCams did reject a batch of blanks because they were .080in too big......
I'll know more when I swap back to standard and measure them.

nickb777

Pm sent in reply Hope it all works out for you I hope its not comp cams as I have a blower cam on it's way!!

vocky

I will be checking my comp cams when they arrive, that would certainly cause the cam bearings to 'pick up' 🙁

nickb777

vocky said:
I will be checking my comp cams when they arrive, that would certainly cause the cam bearings to 'pick up' 🙁

Anything we can do about it if it is apart from sending them back to the states again?

2-20

How did you break in the cams ?
It seems that this phase should not be overlooked.

vocky

nickb777 said:

vocky said:
I will be checking my comp cams when they arrive, that would certainly cause the cam bearings to 'pick up' 🙁

Anything we can do about it if it is apart from sending them back to the states again?

two options,
get the head bearings line-bored, this may be a good idea for TheHood dunno..

get the camshaft bearing lobes reground, I'm sure pipercams would be able to correct it if it's an issue :?:

a good way to check is to fit the cams without the followers and make sure they turn easily when the bearing caps are correctly tightened :thumbup:

TheHood

2-20 said:
How did you break in the cams ?
It seems that this phase should not be overlooked.

Plently of cam lube on the lobes, then ran the engine at about 2500 rpm for 20 mins whilst keeping my eyes glued on the water temp gauge. :o

TheHood

Swapped the cams back to standard and the noise is gone dunno..

Measured the CompCams and they're the same within the error range my calipers / eyes can manage (about 0.04mm), so the wear must be due to oil starvation or my incompetence notsure.gif

Courtenay's should be able to come up with an answer when they gently empty my bank account for a CS5 when i take it into them tomorrow morning.

vocky

I hope they can sort it for you 🙂

TheHood

Just for the record; both Courtenay and the chap they use for their head porting work thought the markings to the bearing caps and head were no cause for concern and were happy to re-use them :thumbup: To be fair, the pictures above do seem to highlight the "witness marks" more than is visible to the naked eye.

The exhaust valve guides were replaced as they were showing very early signs of wear - done more as a precaution with longevety in mind given I plan to be using the car on track a bit more next year.

Oh, the CS5 and lightened flywheel are rather good. 😃

edited for spelling

vocky

thats good news 🙂

did they get the cams re-fitted ok ?

exmantaa

Did you check the base circle of those new cams?
The Z22SE's lifters are not very happy with a smaller than normal base circle... (regrind cams)

2-20

IIRC They are 30 mm base circle.
What is the base circle of stock cams ?

vocky

I just checked some saab cams and they are also 30mm base circle :thumbup:

TheHood

I checked the base circle of both the Comps and standard - both are bang on 30mm.

Vocky: The CS5 included the whole Schrick kit (double valve springs, ti retainers etc.), so I'm not using the Comps. I'll probably sell them on with the offer of a refund if the buyer expirences the same problem as me with the noise.

« Previous Page Next Page »