So I've read that pre 1979 1.3L X1/9 engines are interference yet 1980+ 1.5L are non-interference, is this 100% accurate? Is there anyway to bend the valves on a 1.5L? Say downshifting at real high RPM? I'm trying to understand if such a thing is possible on a freewheel engine? Learn me please...
You are correct that the 1.3 is interference and the 1.5 is not.
Do you think the head might have been shaved in the past?
Well I was told the PO downshifted hard, slipped the timing belt and 'bent the valves' but I'm assuming if it's an 84 it really just needs a new belt and be retimed...
Fit the 2l twincam if it does need more than a belt and retiming?
I'd wager you are correct, Raze.
One quick way to tell: If you yank the cam cover and the exhaust valve clearance is excessive (and I mean a LOT), the bent valves are stuck in the guides. If it's awithin a few thou of spec, you're probably good.
You can bend the valves if something bad happened, but a simple break will not do it. I know this from experience. Even if it does have bent valves though, it is a very simple engine with inexpensive parts. I personally prefer it over the 2 liter. It is a sweet motor that will rev past 9k if built correctly. My old 1500 motor I put in my '74 X1/9 had about 120hp with a cam, dual webbers, header, etc. While that doesn't sound like a lot today, it is almost double the stock figure. A cam makes a HUGE difference in those motors!
Jerry From LA wrote: One quick way to tell: If you yank the cam cover and the exhaust valve clearance is excessive (and I mean a LOT), the bent valves are stuck in the guides. If it's awithin a few thou of spec, you're probably good.
What's spec on the clearance?
The 1.3's are interference, the 1.5's are not.
Is it possible to bend valves on a non interference engine? I'd say yeah. 1.8 VWs are allegedly non interference yet I had several come through the shop with bent valves. In every case it happened at highway speeds. Same with the 2.5 DOHC Subaru motors. That one was due to the valves hitting each oter, not the piston. Again, that was a high speed breakage thing.
Raze wrote:Jerry From LA wrote: One quick way to tell: If you yank the cam cover and the exhaust valve clearance is excessive (and I mean a LOT), the bent valves are stuck in the guides. If it's awithin a few thou of spec, you're probably good.What's spec on the clearance?
I can't remember but I'm talking a profound amount of clearance here. Like a quarter inch or more.
racerdave600 wrote: A cam makes a HUGE difference in those motors!
Amen, brother. The US-spec cams were designed to get the cars through emissions. Even the stock Euro-spec cam is a big improvement. Power improves everywhere, even down low.
gotcha, then I think I'll be at least going to look at this car, will ask the PO how he 'knows' the valves are bent, see if he took the VC off...
If you have not purchased yet, I wouldn't plant the seed in the owner's mind that the valves might not be bent.
He could be assuming it is an interference.
I'm well aware of that m4ff3w, but if the valves are indeed bent, the car is worth much much less than the much less I was willing to spend... 
BoxheadTim wrote: Fit the 2l twincam if it does need more than a belt and retiming?
This is so not a bolt-in. Way too much work for what you gain. You'd be better off buying the nearly identically sized Lancia Scorpion and the work is already done for you.
Turbo Uno
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