UPDATED: Ok to run with 'loose' valve clearance?

[BurbankJalopy]

Hi all. I did some head work to my car so now my valves are ticking. They're definately loose but it isn't as though the cups are going to fall out - it just sounds like a louder Honda engine with it's ticking. In your opinion is it ok to run like this for a few weeks, maybe few hundred miles until I feel like messing with changing the shims? I personally think it is fine, I can't imagine any damage being done by the valves being too loose. I haven't measured the clearance. Thanks for your opinion. One more question: should I alter the ignition timing given the fact that now I've got maybe a tiny bit more compression caused by the head losing thickness and hence smaller combustion chamber?


If you're curisous, I had a few things going on that I wanted to fix. It had a cam housing leak, broken exhaust stud, the heater pipe outlet was ready to fall apart, and head gasket minor leak...all those things coupled with our freezing cold weather lately (55degrees) preventing me from my mountain biking, giving me the itch to fix something. So basically I had a head rebuild and new gaskets. The head gasket was leaking a slight amount of compression into the cooling system (after a day of driving it'd become a problem and I'd have to open the steam valves to release pressure). I took it apart planning to replace just the gaskets....well of course one thing leads to another on these cars and it was best to just spend a little more time and money to get the head redone. The cylinders still had cross hatching marks which was a nice suprise as to the history of the engine. I also took off the oil pan and in there was nice and clean too. I had to have .0015 taken off the head to get all the pitting out. It fired right up after about 3 revolutions and runs great!

[So Cal Mark]

it would be nice to know just how loose is loose. Excess clearance is a little hard on the cam besides costing power

[BurbankJalopy]

Hi again. I was able to measure the clearances I have with the current valve shims, please tell me what you think in terms of driving with these clearances;

Intake in thousands of an inch order of 1 to 4 cylinders;
.028 .028 .026 .027

Exhaust
.026 .022 .017 .024

I believe it's supposed to be .017 intake and .018 exhaust (for a stock 81 2000 fuel injected) Do you guys think it's ok to run with this excess clearance for a little while (a few hundred miles at most)? I do get the sense of valve float/surging at high rpms, other than that it's just a little 'tickier' than normal.

I plan to buy and wait for shipping on the valve shim tool so I can measure the old shims......Does anyone have a trick instead of buying a $45 valve spring/shim compressor from IAP which will be used just a few times? I wish I had a spare distributor hold down bracket, if you ground out the center a little larger I think you could use the cam box hold down bolts and tighten down the valve that way to get the shims out. And yes, I admit it was dumb to not measure the shims while I had it all apart. So again, two questions;
1. Do you think it's fine to run for a few hundred miles with the clearances noted above?
2. Any easy way to get the shims out without having the tool from IAP?

Thanks a lot!

[So Cal Mark]

I haven't tried running clearances that large, so I can't comment on how long it will take for damage to occur. I sure wouldn't run it any longer than necessary.
The right tool makes the job do-able. Without it you'll have to figure out how to depress the valves to get the shims out

[ventura ace]

If you plan to maintain your spider yourself, the valve shim tool is a tool that you should own. You'll also need a set of micrometers to measure the shims (calipers will do, but a micrometer is more accurate), a syringe to clean out the excess oil in the cam towers, little sharp tools or compressed air to remove the shim, and replacement shims. I wouldn't run the engine very much with valves that loose, but I don't think 2 or 3 hours would cause much harm. The cam lobes are supposed to hit the shims with their 'ramps', which are ground at a slightly different approach angle to 'ease' into the shim, and at those clearances, I believe that the cams are missing the ramps and slapping the shims more abruptly, which is not good for the shim or the cam lobe.

I have the shim tool, and could help you make your measurements. Give me a call if you want to bring it up here to Ventura to take a look at it.

Alvon
805-338-1767

[sptcoupe]

Valve lash is like an accounitng ledger - off either way is not a good thing.

[BurbankJalopy]

Hi Alvon / Mark
Thanks for the input. Thanks Alvon for the offer to help with it...Ventura is a little too far I think with the valves the way they are but I really appreciate the offer. What I'll do is order the valve shim tool and wait for it then get the right shims after that. I feel so dumb that I didn't think to measure the shims when I had it all apart - it's a good lesson I suppose.

[baltobernie]

Mark is too polite to say this, but that won't stop me

After your tool arrives, you'll need to remove all eight shims and measure them. If your motor is like most Fiat TC's, the shims in there now are cupped, so you'll have to guess what the new shim thickness should be. Then you'll order and wait for (hopefully) the correct shims, install them and check new clearances. Repeat ordering process, most likely.

This is why UPS has shiny new trucks, and we have old, beat-up dirty ones.

If the car is already in Los Angeles, why don't you simply take it to Allison Automotive and have the job done right. It's probably the only time you'll ever need this service performed, and he'll most likely find something else under the car that you've missed. All for less money than you would have spent DIY.

I could see if you lived in Podunk, but jeez