Honda Civic Timing Belt

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Get him to check the valve clearances by turning the cam(s) over by hand while the pistons are at half-mast. Bent valves will have HUGE clearances compared to the others.

Simple and cheap.

'Curly'

"Kylie" wrote

The risk of severe damage is higher at higher rpm or at higher speeds and decelerating in gear. The risk is lower if you're accelerating from a stop but not above 25-30-mph on autos. In a manual transmission the risk of damage is higher.

First off, the damage typically sustained by the pistons is usually minimal. When the pistons hit the valves, there's usually just some small dents in the top and they can be reused without any problems. The most damage is to the valves. These get bent and will not seal flat against the valve seat. Since the valves are not seated, as Curly noted, the clearances on any bent valves will be excessive. You don't even need to use a feeler gauge to find them. It takes just 15-20 minutes or so to pull the valve cover and check all the valves. If you're going to junk the car rather than pull the head and replace the bent valves, then this might be the best option. Keep in mind that older cars are a lot like onions. Once you start peeling back the layers to fix one problem, you find a lot more problems. There's usually no getting around it unless the car has had excellent maintenance (but it wouldn't likely be in its current status if that were the case). It sounds like you've evaluated the condition of the car and judged it not worthwhile to repair the valve train damage. Since this is the case, just get the clearances checked and then decide.

Eric

Great words of wisdom, Eric. I'll have to remember that (and where it came from, although I'll keep thinking it was from Shrek.)

Mike

I've never watched Shrek. The statement is almost verbatim of what we told customers when they brought their older cars into the shop. It helped lessen the impact of dealing with reality. With the OP's '84 Civic that's likely been neglected it might be like opening the bottomless can of worms. With pulling the head, it would be reasonable to replace the valve stem seals, overhaul the CVCC valves, repair assorted vacuum hose and coolant hoses problems, probably overhaul the distributor, and then even if you were careful, there's probably enough crud in the carburetor float bowls that's accumulated over the years that it would get sloshed around and wind up plugging up the carburetor.

Eric

Fast, sporty drivers can damage there connecting rods or other areas of the engine block if they reach very high speeds. Especially going downhill where the pistons will continuously beat on the twisted valves. Although, the sound will be very loud and obvious, this is pretty rare.

This is well said and very down to earth.

"'Curly Q. Links'" wrote

As you get him to grab the cam wheel to turn it over by hand he'd be surprise to find the cam stuck. Most often the belt snapped because the camshaft is poorly lube.

Usually, you don't need to get the piston at half-mast. As you turn the cam wheel several revolutions by hand to visually check the valve clearance the valves pushes the piston out of the way. And the odds of it at TDC is close to 1 in 100. If it happens to be at TDC I'll give you our family horse - with saddle. :-)

I was clicking off 120km/hr and broke my tb in my Integra. Absolutely no damage and it was standard. My friend was driving his dodge colt a few years ago down a local st. going around 20k, belt broke, and he tried starting it 2-3 times......the motor was toast.

The key is do not try to start you car if it breaks down you you think its the timing belt. Pop the cover off and have a look

I lost confidence when I saw Gates listed the Volvo B230F engine as interference. It's been pretty well hashed over on alt.autos.volvo, and the experts agree it is a clearance engine even with the non-standard high lift ("K") cam. However, it probably beats a wild guess.

Mike

"Michael Pardee" wrote

Interesting. I wonder if there's some subtlety in certain engine designs that result in their being a gray area here.

"Elle" wrote

Oops. I reckon it has indeed been a long afternoon bustin' a control arm bolt free! You give a lead to one important subtlety right above, and it went right by me!