73, 340 compression question

[Strawdawg]

What are you asking?

Steve

[Chryco Psycho]

Generally you are safe to around .525 lift with pistons with valve reliefs , you will probably have to trim the valve guides a little or at least change to apositive seal to stop the retainer crushing the seal or hitting the top of the guides . if you stay around .500 lift with 230 -240* duration @ .050 you should be fine , But I would still check it . I have used .590 lift cams with 250* duration with notched piston in the past with steel shim gaskets in 440s

[mrbill426]

Oh I would not be going that high  at all Chryco, I am still using stock exhaust manifolds.  Thanks for that info though 


Strawdawg, it was more of a comment, no question  mark, my fault 
Will a LD340 work (fit) with factory A/C?  And, also will that intake work with the stock air cleaner, and still be able to close the hood w/hood blanket?

 

Generally you are safe to around .525 lift with pistons with valve reliefs , you will probably have to trim the valve guides a little or at least change to apositive seal to stop the retainer crushing the seal or hitting the top of the guides . if you stay around .500 lift with 230 -240* duration @ .050 you should be fine , But I would still check it . I have used .590 lift cams with 250* duration with notched piston in the past with steel shim gaskets in 440s

[Strawdawg]

Those, I don't know. .   I am guessing some where around 220-224 @. 050 would be a good cam choice for what you are proposing and no concern about clearance as Chryco said

Steve

[cudabob496]

Good thought, but you still need a way to verify how deep the reliefs are ie: valve to piston clearance. Usually the minimum recommended
is .060" on the intake and .100 on the exhaust. If heads were on then you would have to get each piston on TDC, remove
the valve springs, and put a dial indicator on the stem tip. Lower the valve until it touches. Measure the total travel
of the valve and subtract your minimum clearance from the total. Personally, I would pull the heads and measure with the clay.

Perhaps, but Chryco had suggested that if reliefs are there, should be ok for this situation, and no need to measure depth.
Many times we'll buy an engine, having been told whats inside, and it turns out not to be the case.

[Chryco Psycho]

Well the cams I typically use are aggressive , Lunati has the VooDoo which have short duration but high lift , so a relatively mild cam around 230* @ .050 can still lift close to .500 , my theory is lift is free get all you can with a ny duration .
 I am in no way suggesting you will be OK , you Should be OK but I would still check , a valve relief doesn't guarantee enough clearance , different piston mfgs could use a different spec for the diameter or depth , even swapping heads can cause issues , when we swapped eddy RPM heads onto a 440 the valves were located slightly differently in the heads so the valve missed the relifs & hit the pistons so the pistons had to be fly cut 

[mrbill426]

Okay I will look around for a cam with a profile like that.  Using stock exhaust I obviously have limitations but I do want something with a bit more low end get movin than stock.  Right now it has 3:23 gears but it's getting 3:55s.  And yes, I WILL check valve clearance 

Still have to figure the LD-340 "fit" with A/C and original air cleaner.

Thanks!

Well the cams I typically use are aggressive , Lunati has the VooDoo which have short duration but high lift , so a relatively mild cam around 230* @ .050 can still lift close to .500 , my theory is lift is free get all you can with a ny duration .
 I am in no way suggesting you will be OK , you Should be OK but I would still check , a valve relief doesn't guarantee enough clearance , different piston mfgs could use a different spec for the diameter or depth , even swapping heads can cause issues , when we swapped eddy RPM heads onto a 440 the valves were located slightly differently in the heads so the valve missed the relifs & hit the pistons so the pistons had to be fly cut