rob rossitto

mine did, but if the screen gets blocked....

IIRC, some of the cams just drop in (I always forget which, sorry), and 1 of them needs to either have the bearing redone, or the head modified for the journal....if you compare your set to a stock set, you can probably see which way they went... I was quoted $300-$500 to have it done, thought just dropping a GT set in would be cheaper, and then found out I had to have the GT set cleaned up - the pitting was pretty obvious on my set/hard to miss...was a good excuse to have them "fixed" (reground about .020" or so for more lift and increased duration)... since the hydraulic lifters have about .070" of "play", I got by w/keeping my stock springs/etc and just had the valve hts changed a bit when they did the 968 valves/porting stuff...

if the cams that you need to replace are not the one w/the required work, you might even get by just swapping the ones you need... if you want, I can send you my set so you can ck it all out/compare what they did...they are just sitting around at greg's place/taking up space...just promise not to drop them into the pan too ... PM me w/shipping info whenever you're ready ...

mark kibort

How do they fail?? i assume that you machined the "spiders" for the 16 valve so they could have the adjustable timing? ive never got that far into the cam pulley mech. before.

Mk

PorKen

The 'spiders' are supposedly cast, and can fracture, but how I haven't heard. Overtensioned timing belt, and/or undertorqued cam bolt, perhaps.

Correct. I also made a 'pointer', referenced to the woodruff key, to allow setup. Even if you don't change the valve timing (I advanced mine by 3 cam degrees), synchronizing the cams makes the engine run much smoother. Typically on 16V engines, the right cam is ~2 cam degrees retarded (sometimes up to half a tooth, 3.5 degrees), even when the engine is warm.


click pic for install thread

blau928

Hey MK,

I think I have a similar situation to yours at Laguna happen to me on Sat... But, my tensioner light came on, and then rough running, then I shut it down... Hope it's only a jumped tooth... I'm thinking it may be the plastic thing-a-ma-jig/doo-hickey that tensions the chain... Can't get to it until the week end, and I'll let you know what I find then....

Hopefully, some of your luck rubbed off on me from being at the track and helping with your car...

Cheers,

mark kibort

Yep, it could be, but first, i didnt have the light to warn me or indicate that the tesioner was loose, or even loose for a moment that happens when you have a loose belt. second, it did run very very rough for me , and that was 3-4 teeth. (almost like the right side of the engine was off) Now, if you think your cam sprocket jumped teeth, thats a long shot. i cant imagine that it could jump teeth, without doing some major damage. dont you think that you may have just jumped cam belt teeth, and maybe only 1-2 since it was not catastrophic when it happened. did you trailer it home, or drive it?

in any event, do the compression check as we did, then hope the whole side is off by 50psi!, then you know!!!

lets hope its just a belt issue like mine was!!

Mk

blau928

Hi Mark,

I had it flatbedded it home, as it happened on Hwy 1 about 10 miles from the house. I think it is either the belt tensioner, the cam belt sprocket, or the plastic chain tensioner thing. The back of the belt looked fine when I peered into the breather holes on both sides. I will remove the covers (Cam Belt first, then Valve ) to check if the toothed side of the belt is good, then check the plastic tensioner things after popping off the VC.. If all looks well, after this, then compression test the thing. I think the problem should be found by then, however, if not, then off to the shop, as my hands will be cold by then as it's a bit colder now with all the rain we had lately....

BTW, After the light came on (3500rpm), I eased off the pedal, and coasted to a halt at an exit ramp. Car was still running, but a bit lumpy idle... I then eased around the corner, and the idle turned to bucking and wheezing, so I went up a block more to be out of traffic, and shut it off. Now that I think about things, I heard a slight scraping noise from the left valve cover the day before, but dismissed it as the PS pulley.. It also idled rough the night before for about 5 seconds, and then ran normally. With the new exhaust, it's a bit harder to hear all the little things as before.. Normally idles very solid, no lumps or sputters at all.....

I think I need to get a trailer... Most likely will rent one and drag 'er up to the shop if it comes to that...