My buddy & I are working on a friends 71 Comet that has a 70 351 Cleavland 4v. The motor is full stock, but it hasn't been run in a long time. It does run but has a lifter tick in the passenger side & smoke comes from the breather on the valve cover(RH side). The valve guides are probably shot also, the motor never ran right especially at idle, we did find a huge vacuum leak at the rear of the intake-the rear end gasket squeezed out! So I'm about to put new gaskets on, minus the end ones(just use RTV) & was wondering should I just replace all the lifters now or maybe do a cam swap too? But with this neglected motor would that do more harm than good? You know, blow something else up? Any ideas on this? Thanks...
I agree, a full rebuild (and certainly all new gaskets would be included) is the best thing for the engine. I would convert to roller lifters and cam too.
Probably has a sludged up lifter (its been sitting for how long??) A rebuild is in order if it has blowby and you think the guides are bad. You have to pull the intake any ways...Check the lifters/pushrods while your in there see if it has a flattened out lifter/bent pushrod...Dont throw a new cam/lifters in it unless you are certain it is a sound engine. Leakdown test is in order as well as a cranking compression test...Good luck!!!
Yes, definately needs a rebuild. The thing is I'm selling the car & it is such a nice ol car that I just want to quiet the ticking down. People have looked at the car & commented on it, but they notice the tick, I'm honest with them in saying that it is old & probably needs a rebuild. ***I pulled the intake off & all seems ok, I'm not a master mechanic but all pushrods & rockers seems fine, but there is sludge all over the place-very neglected! I've decided to just throw a new set of lifters in, just to by some time for the next buyer & they can rebuild whenever they want, or just cruise around time to time as is. The car doesn't really smoke out of the exhaust, just the oil breather-I'm sure the guides are shot too, other than that it's ok.
I had a 351C in a 70 Torino GT when I was in High School and I agree with everyone on the issue. I would completely rebuild this Motor sparing no expense or get rid of it and start from scratch with a 351W.
In most cases the combination of new lifters/old cam or old lifters new cam doesn't work out very well. Just a matter of time before one eats the other. The smoke out of breather is the worn out rings causing some of the compression to get into the oil pan. Just simply worn out.
