ALFAGTV6.COM

[FTHurley]

About a year and a half ago, we noticed a knocking on the right side of the motor in my Dad's 1986 GTV6 (2.5). Using a stethoscope, he pinpointed the noise to the camshaft area on the right side. Pulled valve cover, and found a point exhaust lobe, which we've been told can happen with time, and cause such a noise. The noise did NOT seem to be from anywhere else, namely lower, near the crank, so we ordered new cams, and it seemed "S" cams were the most easily available replacements. We looked around, and found a place that was selling them for about half of what everyone else was getting for them. We know ... you get what you pay for ... but we were busy with a variety of projects at the time, and without really thinking about it more deeply, we ordered them from this operation. They showed up, and we installed them. We adjusted the valves to spec, and reassembled. After running, the noise on the right side had gone. However, we now had a knock on the left, which would only become audible once the motor had warmed up, but could be felt by placing your thumb against the cam pulley nut right from start-up, and once audible, could be made to go away by placing pressure against nut with thumb, as if one were pushing the camshaft back, away from a point of interferance. Needless to say, we disassembled, rechecked, retorqued, examined, andall of the other "Oh my God" inspections, but the noise would not go away. We got to the point where we felt we were ruining the motor with all of the assembly and disassembly, but the engine showed good resilience, and thankfully, nothing failed or stripped during this time. We bought a second left-side cam from this company, and installed it with no other changed, and the pulsing knock of the cam was gone immediately, and the thumb-on-pully-nut test showed no vibration. We did a final recheck of everything, and with it all the spec, reassembled. We returned the apparently bad cam to the company, and were refunded for it. The car ran well, and has been for about 20K miles. The left side was very slightly loose in the valve adjustments on two intake valves, so there was a very slight bit of tick from that area, but we could isolate the noise to those valves, and everything else seemed great, despite all of the work done on the head area. Recently, we pulled the valve covers to tighten up the loose valves, and while there, looked a very light noise on the right, which proved to be a similar fore-and-aft pulsing of the camshaft, only not as pronounced as on replacement A on the left (the returned "bad" cam). It is a slight thrum that can be felt through the pulley nut with the thumb. Same situation, but not nearly as bad, and we missed it initially because the left side noise was the proverbial 800 lb. gorilla while we were doing the work. We took this opportunity to do a good, thorough valve adjustment all over, because we were doing a water pump, timing belt, and tensioner, and decided to combine services to save time. While we know that a "thumb test" is about the most primitive of diagnostic tools, it is also quite apparent when you do it that there is a thrum/knock transferring through the nut, and if you apply slight inward pressure, the noise and vibration goes away, with no apparent change in the motor's running. The original bad cam noise on the left was unlivable, and made us wonder if we were ruining the motor. This noise on the right, while similar, is much less pronounced, and would almost be livable, except that we are worried that over time, this unnatural wearing from contact could lead to a bigger problem in the head area, and on this motor, we are always concerned about valve interfearance, as is everyone else who owns one, not to mention any other potential damage from inappropriate cam to head contact. Has anyone else who has done this swap for "S" cams ever run into anything like this? Any help, advice, or commiseration would be appreciated, since we're now wondering if we have another bad cam that just didn't catch our attention right away, or if this is all part of the "S" cam swap process. We know there is talk of "clearance" issues with "S" cams, but once we finally got the left side done, there was no noise, and light rearward pressure makes the right side noise go away, so it just seems more like a bad cam than a real clearance issue. Thoughts? Thanks.

[Barry]

FTH,Are the cams original Alfa Romeo factory items??
I have in 25 years never experienced the problems you guys have here..
Even when our local cam grinders have made billet job for the likes of myself and Dawie,have we not had these hassles..
I would reccomend getting an original set of s cams from someone close(Factory cams) and installing these.
It sounds as if the cam supplier you now have has not done the cams correctly..

What do the trhust faces on the cams AND the caps look like after all this?Im not too worried about your cam here,but more about the cam caps..
These,if worn badly,can be rpaired and hand finnished to work as per oiriginal again.
Alternatively,if they are real bad,replacement caps from another motor can again be hand finnished to fit and work..

[junglejustice]

Barry is right.
I would just add that the bad name "regrinds" get all of the time is a bit of a mis-conception and lack of knowledge... You can take a brand new factory cam and put it on an engine with worn cam-followers and it will still wear those cam-lobbs to a knub in no-time!

While some of the cams that Dawie and Barry uses are produced from billet-stock and others are welded and reshaped by experts such as Vanderlinde, (sometimes even nitrated/plasma heat-treated for hardness), even this precaution is no guard against a worn cam-follower...

As for the finger-test/knocking - a finger can make you jump cam timing

[tomp]

But only once!

It kind of sounds like it you want an accurately ground high lift cam you have to have custom made. That would be sad. Surely there are a few suppliers of good alfa 12v cams out there. Any suggestions?

[junglejustice]

I have some Group 1 cams straight from Glenwood Motors - Works well in a 12 valve 164 or in a 2.5 or 3.0 Milano/75 V6...

For the 24 valve engines I have some GTA Stage 1 cams here that just brought back with me from South Africa (I run them in my 1995 164 LS - Super - and they work fantastic!)

Please email me off-line at john@reginaceleste.com or call me at 425.941.4747