New 340 Cam...Just can't decide?????

[woody9512]

   I'm currently searching for a Hyd Cam for my 71 340 Cuda with power brakes (4-speed @ 355gears) to replace my Comp Cam's Magnum 270H (1800-5500 rpm range) which has.470 lift and 224/224 duration @.05 and @270/270 @.006 (stock non adjustable rockers) rest of engine is stock except for headers. I need to replace cam due to a bad lobe and lifter. I was looking at several different ones Lunati Voodoo Etc...and kind of like the Engle brands (either K-56Hyd........Adv Dur 272/272..Dur @.05 224/224...lift 504/504)  or the K-58Hyd (Adv Dur 276/276...Dur @.05 230/230...lift...520/520...
    Here is my question/concern...I realize that I will probably need to change the springs to use either of these cams but will I run into a big problem with the extra lift in the valves with maybe having them hit the top of the pistons??? Is there an easy way to figure that out before hand if this will be a problem??...I have no idea as to what lays under my heads as to pistons as it hasn't been apart since I got it several years ago.......Maybe I'm just better off to pick another Comp Cam that is compatible with my current springs and just go that route???  Decisions/Decisions/Decisions???
As always Thanks One and All "Tim"

[Chryco Psycho]

you can rotate the engine until the valve is 6* before TDc for the exhaust valve or 6* Adtc for the intake valve & depress the valve & measure the clearance with a dial guage
 having said that I have never seen a valve come to close to a piston with .520 lift or less
 my choice would still be the Engle cam & I have used a lot of them , the Voodoo is close but just slightly milder , either will work well

[woody9512]

Thanks Chryco......that makes me feel a bit better to say the least.....which Engle size would you suggest the K56...or the K58???....I may go with some ported heads down the road at some point and if the new cam will work with what I have in the engine now I would like to have a cam already installed that will take advantage of the heads if and or when I get them on??

Thanks Again....."Woody"

[matt63]

My engine builder strongly recommends adding an anti-wear additive to the oil to prevent cam lobe wiping which is more prevalent with the newer oils.  I believe it is the Federal Mogul lube.  I can get more details if you wish.

[woody9512]

If you could get more info on that anti wear lube I certainly would be interested. I have no idea why just the bottom of the one lifter and the single cam lobe wore the way that it did?? All the other lobes and lifters were fine.......go figure!!!!
"Tim"

[Chryco Psycho]

GM dealers carry EOS ...engine oil suppliment , it adds the zinc & other wear additives lacking in most new oils
I would use the K 56 if you want the same powerband as the cam you had , even with ported heads the K56 works well 
 if you have a 2200 + stall converter the K58 will work better

[woody9512]

I have a 4-speed so I guess I might go with the bigger K-58.....I assume that my non-adjustable valvetrain will be good enough. Does anyone know will I need the longer pushrods as well or would you think the standard length??? My old cam had the pushrods just a slight bit longer than the standard ones.   
"Woody"

[Chryco Psycho]

stok is 7.5" the longer ones are 7.55" if you have the 7.55 you should be fine

[woody9512]

As per usual.....you guys certainly helped me out with my decision....and once again.........THANKS VERY MUCH!!!!
"Tim"

[Chryco Psycho]

you are welcome
 most high compression piston that get close to the head will have valve reliefs cut into them , if the piston is lower compression it wil generally have room to clear with out reliefs , it still doesn`t hurt to check clearance but I have yet to have a problem

[tactransman]

I have no idea why just the bottom of the one lifter and the single cam lobe wore the way that it did?? All the other lobes and lifters were fine.......go figure!!!!
"Tim"

I had a cam do the same thing in a 440 that was pretty full tilt(13.5 to 1,1.6 rockers,1050 Dominator,.672 lift) my engine builder told me the cam lobe was not hardened correctly at the factory(it was a custom grind Lunati) he said if it was not broken in right it would have had more than just one lobe bad. He got the cam and lifters replaced for free!

[ShelbyDogg]

If you have a lifter not rotating in it's bore for any reason, that will wear a lobe down in a very short time.

[Chryco Psycho]

absol;utly , I have a lifter form an engine I tore down shortly after having a new can installed & the pattern on the bottom of the lifter shows it was not rotating so the cam was ground poorly & it would have failed very shortly if I had not torn it down

[woody9512]

Is there a reason or reasons as to why a lifter wouldn't rotate in the block?
"Woody"

[tactransman]

I would say the number one reason would be a cam lobe not shaped correctly when the cam was made. The lobes are not "flat" they are made with a slight taper to them so one side of the bottom of the lifter gets contacted first making the lifter rotate .