IT'S ALIVE!!!

[bran100]

4mm pistons, Mark's 274FI cams, lightened flywheel, new clutch plus new seals, bearings, rings, etc., and stock 4-2-1 exhaust.

The valvetrain is a little noisier than I expected. It looked to be dialed in pretty well by Beek. Need to dial in timing and I'd like to find adjustable cam gears and upgrade to a distributorless ignition. I'll probably keep the 4-2 exhaust and replace from the catalytic converter back.

Any thoughts on the valvetrain?
http://youtu.be/LNu-x4Mvxrg

[focodave]

SWEET!
Are you sure the sound isn't an exhaust leak, specifically at the manifold-to-head?
Hard to tell from the video due to fidelity problems, etc.
If the valves were recently lashed properly, it sounds louder than I would expect from the valve-train.

[bran100]

Just checked, and no exhaust leak

[So Cal Mark]

what were the valve clearances set at?

[bran100]

Hopefully you can see the numbers Beek wrote here. I'm honestly, not sure what they refer to.


I used plenty of assembly lube and filled the cam boxes with oil prior to starting.

Brandon

[bran100]

BTW, I'm running 5W-30 with a break-in additive added to the oil. The engine is warm during this video, so from what I understand, the oil shouldn't be the culprit?

[seabeelt]

Funny that you posted this. My 1600 makes the same noise, but on the exhaust side only. I did a break in as well before making any real load or revs on the engine. Probably let it run for about an hour changing the revs from idle to about 1500 from time to time. The noise isnt there all of the time, but I would say 95-99 percent of the time. I did the ole long screwdriver handle to the ear test trying to isolate the noise and it seems to be coming from the valve train. I went around and checked the exhaust manifold gasket and the manifold to down pipe gasket just to be sure. Had to replace the down pipe gasket this weekend as I was getting just a small leak that you could just barely feel on the back of your hand. (Have almost almost 1000 miles on the car now) I do know that BEEK had pointed out a worn lobe on one of the cams where it was hitting the cup and thought it might still be doing so. I have pulled the cam cover, but cannot visually see any new wear or damage to any contact surface. I'm open to suggestions as well, if anyone has any ideas. It does seem odd that it is the exhaust side only. Intake is quiet as a mouse by comparison. I also get an occasional squeel that almost sounds like the belt on the alt but am begining to wonder if the bearing surface in the cam box might be in the mix. BTW the numbers BEEK posted on the cam box look to be the size shim used and the final valve clearance
r/

[BEEK]

its the size shim and the clearance .010 was the clearance and 4.95 would be the shim size, for example. please recheck them though, i do run the cams over a few times and recheck them myself before sending to make sure there are no errors. let me know if there are any issues, because you have the size shim thats in the tappet, if the clearance is different i can send you a replacement. but i would wonder why the clearance had changed, especially if it was just 1 valve, i hope that one didnt get bent somehow. that would usually be the only reason that one valve would have a larger clearance. please be sure to follow the camshaft break in procedures though. call me if i can be any help

[SpecialTool]

Beek, I noticed your cam-tappet clearances are a lot tighter than a book I have for the '75 1.8.Is there some advantage to that? Does it just seem to work better from your personal experience? Maybe I should relash my valves.

[narfire]

I noticed your cam-tappet clearances are a lot tighter than a book I have for the '75 1.8.

These are after market cams. Different clearances than stock.

I have the same cams in my FI and after shimming and then after running for about 2000 kms I checked and re-shimmed the odd one that needed attention and it is quieter than when I had the stock cams in.

[SpecialTool]

I see. What about the tappets, aftermarket also or stock? Are the clearances tighter for these cams due to a larger base circle then? I'm just trying to learn all I can as one day after I get the chassis sorted out there will be a performance street engine build in my '75's future.

[BEEK]

the clearances are the specification of the camshaft supplier. i have run tighter clearances on factory cams with no ill effects, you just have to keep up with the adjustment. imho thats why the clearances are larger on factory cams, because of service intervials. by tightening the clearances you are adding to the duration of the camshaft, very slightly though