Moparts

are slant 6s interferance fit engines?

Posted By: badblubeee

are slant 6s interferance fit engines? - 09/03/10 06:50 PM

The timing gears broke/slipped on my 76 Duster 225 slant 6 and I'm wondering if the valves hit the pistons.I don,t want to put a new chain and gears in and find that the valves are junk.Dave
Posted By: stumpy

Re: are slant 6s interferance fit engines? - 09/03/10 09:25 PM

No they are not interference engines. Just replace the gears and chain.
Posted By: MoparforLife

Re: are slant 6s interferance fit engines? - 09/03/10 09:39 PM

Be smart to check it out. I have seen an awful lot of bent valves and eye brows on pistons in Mopar's 'non interference' engine over the years when the sprocket or chain goes south..
Posted By: slantzilla

Re: are slant 6s interferance fit engines? - 09/03/10 10:56 PM

If it's a stock motor the pistons are at least .150" down in the hole. You'd really have to do something fantastic to hit the valves.
Posted By: Evil Monkey

Re: are slant 6s interferance fit engines? - 09/04/10 05:45 AM

I had the timing gears break apart and the chain slip on the 225 in my old 69 Valiant. I didn't check for bent valves, just put in a new timing chain set, and it ran fine for years, and still ran fine when I sold it.
Posted By: MoparforLife

Re: are slant 6s interferance fit engines? - 09/04/10 12:09 PM

On /6 it would be very rare if at all. all I said is that it wouldn't hurt to check.
Posted By: Dakota_Don

Re: are slant 6s interferance fit engines? - 09/04/10 06:43 PM

broke mine, and NP, i think you will be ok, the pistons are way down in the hole..
Posted By: stumpy

Re: are slant 6s interferance fit engines? - 09/04/10 06:48 PM

Quote:

On /6 it would be very rare if at all. all I said is that it wouldn't hurt to check.


Not everyone has the extra money and time to tear the top off an engine just because. I have never seen a stock leaning tower of power bend a valve because of a timing chain failure and I've been doing this stuff for 45 years.
Posted By: slantzilla

Re: are slant 6s interferance fit engines? - 09/04/10 11:40 PM

At stock lift the valve heads barely clear the top of the chamber if at all. Net lift is less than .400", the chamber is pretty close to that deep itself.

With the pistons at -.020" in mine I didn't even have to cut valve reliefs until I went to a .558" lift cam and put 1.6 rockers on it.
Posted By: MoparforLife

Re: are slant 6s interferance fit engines? - 09/05/10 01:13 AM

Quote:

Quote:

On /6 it would be very rare if at all. all I said is that it wouldn't hurt to check.


Not everyone has the extra money and time to tear the top off an engine just because. I have never seen a stock leaning tower of power bend a valve because of a timing chain failure and I've been doing this stuff for 45 years.

Like I said it would be a real rarity if it happened with a /6. In fact if our mechanics would have had to make a living working on /6's they would have starved to death in a real hurry. They were so close to bullet proof it was scary.
Posted By: badblubeee

Re: are slant 6s interferance fit engines? - 09/05/10 03:06 AM

Hey, thanks for all the replys. I didn't do anything wild to make this happen-I just parked in the garage,turned it off and later when I tried starting it it just spun over real good(cause open valves) and wouldn't fire -
I had this happen years ago on my 69 RR and after replacing the gears and chain it ran on 5 holes.
I've had about a dozen different slants and this is the first internal failure and this car had a easy life so ya just never know Dave
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