Alfa Romeo Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
971 Posts
Discussion Starter #1
I am bumbed to report that I just bent valve(s) on my spider after adjusting cam timing and failing to sufficiently tighten the 55mm intake cam nut.

I did a leakdown on cylinder #1 which showed, to no surpirse, a severe leak through the intake side. I am getting ready to pull the head but how do I ensure I have the intake camshaft nut torque to the correct 55 ft-lbs. (IIRC). I have a wrench that will fit the nut but have hard time holding the intake camshaft tight enough to torque the nut (while holding the cam timing in place).

Help! Don't want to go through this again after replacing the valves.

I should have left well enough alone. My car was running great but had somewhat of a lumply idle. I knew that the cam timing was not correct for the cams in the car (RJR mild cams for S3 '84 spider).

Looks like I'll be calling Richard again and contributing to his boating funds!
 

·
Premium Member
Joined
·
13,991 Posts
I hold the crankshaft with a 1 1/2" socket while I pull hard on the 22mm wrench on the camshaft nut. I use loctite on the nut as the tab washers usually break. I would have expected the little hardened bolt that goes through the holes in the cam flange and the sprocket to keep it in correct time. I use loctite on that one too.
 

·
Super Moderator
Joined
·
10,588 Posts
I would have expected the little hardened bolt that goes through the holes in the cam flange and the sprocket to keep it in correct time.
Right! It isn't the amount of torque on the 22mm nut that holds the camshaft in phase with the sprocket; it's that small (5mm? 6mm?) through bolt that pins the two together.

dghii: From your post, I am guessing that these bolts weren't installed. See Centerline part number LT901.

 

·
Premium Member
Joined
·
13,991 Posts
I am getting plenty of practice with this. I have a new exhaust camshaft that is not behaving as expected so it is a case of move it one hole and test it. If that is good then move it another, if not move it in the opposite direction. check piston valve clearance. Adjust the jetting if necessary. Do the same with the other cam. You can spend days doing it.
 

·
Registered
Joined
·
971 Posts
Discussion Starter #5
I am getting plenty of practice with this. I have a new exhaust camshaft that is not behaving as expected so it is a case of move it one hole and test it. If that is good then move it another, if not move it in the opposite direction. check piston valve clearance. Adjust the jetting if necessary. Do the same with the other cam. You can spend days doing it.
Thanks for the replies. My problem is with the intake camshaft. I can get the Ex. tightened up, and I do have the small bolt and nut installed through the sprocket.
 

·
Registered
Joined
·
2,578 Posts
Thanks for the replies. My problem is with the intake camshaft. I can get the Ex. tightened up, and I do have the small bolt and nut installed through the sprocket.
If the small bolt didn't shear, the cam didn't move, regardless of how tight the nut is.
 

·
Trained (ex)Professional, , 1953-2018 RIP,
Joined
·
16,232 Posts
Inertia and impact are your friends.
With the cam and chain installed, I simply 'open palm' (impact) the end of the wrench a few times to tighten the 55mm nut.
 

·
Richard Jemison
Joined
·
7,374 Posts
VVT Sprocket

You didn`t say how far out timing was when it bent the valves. If the intake valves were bent it had to be out a great amount.

The VVT nut should have a drop of locktight on the threads when timing has been Finally set at the correct position.

Depending on cam lobe design that position at the unadvanced position should be 116/114 on the intake. Otherwise the "Advanced" position at 102/100 LC might involve p to v contact.

If you bought cams from me you got the Setup PDF file.

Basically a VVT "Performance cam" should be installed initially (after setting lash) using a 100 or 98 LC mark (using a centerline Alfa template) Then turned over by hand to insure that you have .040 P to V clearance. If not you retard the cam one "notch" on the VVT unit and test again until you do. Then the final cam position for it to be locked down at would be that LC position plus 14 degrees. If it was OK at 100 LC then you can set the cam up at the original 114 mark. If it was clear at 102 then you would set the cam at 116 (2 degrees at the crank not cam) retarded from the OE 114 mark.
 

·
Administrator
Joined
·
16,999 Posts
I have a copy of the Alfa camshaft holding tool & 55mm wrench from Totally Alfa.

If you (or any other trustworthy BB member) would like to borrow it and are willing to pay shipping there & back, let me know.
 

Attachments

·
Registered
Joined
·
971 Posts
Discussion Starter #10
You didn`t say how far out timing was when it bent the valves. If the intake valves were bent it had to be out a great amount.

The VVT nut should have a drop of locktight on the threads when timing has been Finally set at the correct position.

Depending on cam lobe design that position at the unadvanced position should be 116/114 on the intake. Otherwise the "Advanced" position at 102/100 LC might involve p to v contact.

If you bought cams from me you got the Setup PDF file.

Basically a VVT "Performance cam" should be installed initially (after setting lash) using a 100 or 98 LC mark (using a centerline Alfa template) Then turned over by hand to insure that you have .040 P to V clearance. If not you retard the cam one "notch" on the VVT unit and test again until you do. Then the final cam position for it to be locked down at would be that LC position plus 14 degrees. If it was OK at 100 LC then you can set the cam up at the original 114 mark. If it was clear at 102 then you would set the cam at 116 (2 degrees at the crank not cam) retarded from the OE 114 mark.
You are correct. I screwed up and set the intake cam at 104 base on the Centerline template. The S3 intake journal mark is 118.
I was way out of tme.

After the car quit (upon first upshift) and I got it home, I pulled the cam cover and the 55 mm nut was finger tight. At first, I thought that was my problem but now I realize that I just flat out set it up wrong.

Crap.
 

·
Registered
Joined
·
971 Posts
Discussion Starter #11
I have a copy of the Alfa camshaft holding tool & 55mm wrench from Totally Alfa.

If you (or any other trustworthy BB member) would like to borrow it and are willing to pay shipping there & back, let me know.
Thank you for the offer. I might well take you up on it. What is the locking tool locking on to? I can't tell from the pic.
 
1 - 11 of 11 Posts
Top