valve lash spec

[mr.belvedere]

i've been running the mp .590 solid lifter cam in my 440 for a while. it's always been pretty noisy, and thats the nature of the beast, but now it's starting to bug me. the cold lash spec for this cam is .028/.032 int/exh., but that seems pretty loose and even by the time it warms up, it still sounds like a hand grenade. so i tightened it up a bit to .022/.026 cold. still a bit loud, but i think the tin intake gasket/valley pan amplifies the noise. i'd like to go even tighter. for the guys with flat tappet cams, how tight do you set your valve clearance, and how often do you adjust them? do you adjust them hot or cold? this motor has iron heads by the way. any input would be appreciated, thanks guys-

 

[Meep-Meep]

I ran a .528 in my 383 years ago and it was noisy too but I didn't worry about it. It just sounded like a street HEMI. I had the lash down to your numbers and it ran fine - and the only reason I did it was to kill some overlap so it would pass the CA smog test (it did!).

I suppose you can go tighter until you drop cylinders after everything warms up, but that may be a little harsh. One other word on valve lash. If you find yourself making frequent adjustments something is moving. Not good. Either seats are sinking or something is wearing out.

 

[HOTMOPR]

I run my big crower at .026-.028

 

[joesnow]

How much for the intake and how much for exhaust?

 

[Meep-Meep]

The exhaust is almost always looser because of the expansion due to heat.

Oops, I just realized I need to make a correction to my above post. I loosened the lash to kill overlap. I believe my numbers were 32/36. After I passed the smog test I was playing with different lash settings to see if it made any difference and I don't believe I noticed much change. This is something I should have done at the track so I could record actual data.

 

[mr.belvedere]

thanks for the info. i'm going to check it this weekend to see how much the clearance has changed(or if at all), since i set the valves this time last year. i've probably put on about 1500 miles or so. it just seems that the noise from the valvetrain keeps getting louder and louder to me. maybe i'm just paranoid, but all i can envision are 16 pushrods and rocker arms flailing wildly under the valve covers begging for mercy!! if the clearance has grown from the .022/.026 mark, i'll have to do some investigating. the seat recession is a possibility.

 

[Canyon707]

I have a 440 drag car and 12 to 1 compression. I am running elbrock peformer heads and a comp cam mopar intake with a 1050 dominiator. I was setting the valve lash at 16i and 18e cold but comp cam told me to take ou 006 and bring them down to 10 and 12 any thoughts on this?? My cam card said to set it at 16/18 hot. Will I get better performance from setting them down that low? bracket race only not used on the street.
Thanks

 

[67 coronet]

i am running the same 590 mp cam as you in my 383 street monster.i run the .028/.032 spec that the designers from ma mopar said to use.i figured they designed the thing and no probs so far.have adjusted it several times and only needed minor adjusting after break in.sure,i think it sounds noisy as hell sometimes,but not all the time.i think it is more me and not that it is louder or softer at random.

 

[Canyon707]

the cam is a solid roller with roller rockers. I am going to try to match up the cam spec (comp cam) I need to set them hot. I am not sure what to expect.

 

[mopar 3 B]

Years ago ran .590 flat tapet 17/21 hot. You can actually hear rockers ratell over the rest of the noise?

 

[383man]

I have a 440 drag car and 12 to 1 compression. I am running elbrock peformer heads and a comp cam mopar intake with a 1050 dominiator. I was setting the valve lash at 16i and 18e cold but comp cam told me to take ou 006 and bring them down to 10 and 12 any thoughts on this?? My cam card said to set it at 16/18 hot. Will I get better performance from setting them down that low? bracket race only not used on the street.
Thanks

Well with aluminum heads the exspansion rate is different so you have to companste more in the adjustment. My custom grind solid flat tappet calls for .020 on both hot and I set them around .014 cold with aluminum heads. Ron

 

[dvw]

First lash is determined by ramp design. Old design = long ramps. Check a few valves when it's good and hot. Write down the results. Check same valves dead cold after sitting over night. Do the math. If your numbers were good hot your cold numbers are what you need. If not add or subtract to your cold reading accordingly. Then always check cold. Way more accurate, why? Because hot the temperature is subjective, 160, 180, 200 etc. Mine with aluminum heads needs .006" tighter cold, Iron heads will need about .002" tighter cold.
Doug

 

[Canyon707]

Thats what I did I took them to 011 and 013 will see what goes down Wed. night. Should be a nice cool afternoon / evening. Try to get this into the 10 second area.

 

[Bigal75]

Bullet solid lifter cam 667/646 lift or 0.016 hot on both intake and exhaust.