question about adjusting solid rollers. I read that for an iron block/aluminum head engine you should subtract .006" from the "hot" valve adj. So after this is done and the engine has been ran should they be re-adjusted with the engine warm?
Jeff

I did a cold valve lash at .004 tighter with a iron block and aluminum heads. But i like the warm settings better.

I just set mine up loose. I adjust them to the hot spec when cold when running for the first time, then adjust them again after it warms up. When the car is warm is the only sure way to do it and I figure why try to figure expansion since it won't be .004-.006" loose for long anyway only until it warms up and better loose than tight.

I just set mine up loose. I adjust them to the hot spec when cold when running for the first time, then adjust them again after it warms up. When the car is warm is the only sure way to do it and I figure why try to figure expansion since it won't be .004-.006" loose for long anyway only until it warms up and better loose than tight.

Actually, it is better tight than loose. Less wear and pounding on the valvetrain by taking up lash. Ever noticed how much quieter is solid is when lash is tightened? How tight you can run the lash is dependant upon the cam manufacturer, it is best to ask first.

Whatever you do, be very consistant in your procedure.

I like the tight lash cams, like my Voodoo 60234. It calls for .018 lash hot, but it can be run as tight as .008. I verified that with Lunati.

Actually, it is better tight than loose. Less wear and pounding on the valvetrain by taking up lash. Ever noticed how much quieter is solid is when lash is tightened? How tight you can run the lash is dependant upon the cam manufacturer, it is best to ask first.

Whatever you do, be very consistant in your procedure.

I like the tight lash cams, like my Voodoo 60234. It calls for .018 lash hot, but it can be run as tight as .008. I verified that with Lunati.

Yeah if you are running it like that, my point was don't. Set them at spec, they will be loose then adjust them as soon as it warms up. Don't run it like that any more than you have to and adjust them right, when the motor is warm.

I like the tight lash cams, like my Voodoo 60234. It calls for .018 lash hot, but it can be run as tight as .008. I verified that with Lunati.


This is a Lunati 50152. card calls for .022/.024 hot.

I always set them cold. To me it's the most consistent setting you can have unless you are VERY fast and have quick access to everything. On a dyno...I can lash them all in a couple of minutes so I can keep pretty close. But even in that case...you would be amazed how much things change in just a few minutes of cooling down.

On aluminum head/iron block big blocks I set them .005"-.006" tighter when cold. Every motor is a little different, so to check...you can either set them cold and run it hard for awhile and then quickly jerk a cover and see what one of each is like...or you can run it hard...then pull a cover and see what it is when good and hot. Then let it cool overnight and check it when cold. That will tell you how much change you are getting and will establish YOUR cold setting from then on.

If I set them cold.....and just have a mild warmup and pull to the line...at the end of a 1/4 mile pass mine will open up about .002"-.003". If I ride around for 2 hours on the highway..they will open up .005"-.006" but that's as much as they move.

The key is consistency on all valves...and when doing it cold you absolutely know they are all the same temp. I agree that best case is to do them hot.....but again, you have to be FAST. As in a very few minutes to have them ALL done.

You can always run them tighter...but be very careful about going looser...it can beat things up. For example I commonly run cams .010" or more tighter on long term running street cars. You *might* lose a little vacuum...but it will be a lot quieter. There is often some power in setting them looser....as it delays valve opening slightly and then really slams them open....but it's hard on parts. Some of the Engine Master's folks were doing some REAL goofy stuff with lash to make the numbers. No wonder they lost a lot of cams in those *street motors*!!

JIM

Actually, it is better tight than loose. Less wear and pounding on the valvetrain by taking up lash. Ever noticed how much quieter is solid is when lash is tightened? How tight you can run the lash is dependant upon the cam manufacturer, it is best to ask first.

Whatever you do, be very consistant in your procedure.

I like the tight lash cams, like my Voodoo 60234. It calls for .018 lash hot, but it can be run as tight as .008. I verified that with Lunati.

Walt,

Did Harold/Lunait say you can run that .008 hot? That means cold, you would set them around .001-.002?

I've been setting mine .007 cold, for a running lash of .014 (my lash grows .007 exactly). Recommened lash for me is 16/18...I just run both at 14. Cant say the motor ran any rougher with the tighter lash. I may go tighter still...I like quiet!

Yeah if you are running it like that, my point was don't. Set them at spec, they will be loose then adjust them as soon as it warms up. Don't run it like that any more than you have to and adjust them right, when the motor is warm.

The issue with trying to set them warm, by the time you get to the last cylinder on that head, the temp can drop dramatically, and then you will be really off on your lash cylinder to cylinder. Set them cold, .006 TIGHTER for iron block/aluminum head combo, and be CONSISTANT in your method.

Walt,

Did Harold/Lunait say you can run that .008 hot? That means cold, you would set them around .001-.002?

I've been setting mine .007 cold, for a running lash of .014 (my lash grows .007 exactly). Recommened lash for me is 16/18...I just run both at 14. Cant say the motor ran any rougher with the tighter lash. I may go tighter still...I like quiet!

Hey Vince, Yes I verified that with Steve/Lunati. I asked how tight I could run it, and he said .008 hot easily.

The issue with trying to set them warm, by the time you get to the last cylinder on that head, the temp can drop dramatically, and then you will be really off on your lash cylinder to cylinder. Set them cold, .006 TIGHTER for iron block/aluminum head combo, and be CONSISTANT in your method. [/B]

I don't know about you, but I can check my valves in 5 minutes and I'm pretty sure the motor is still warm enough. Even 10 minutes will not let it cool enough to change lash noticeably.
If you are worried about a drop from first to last valve, then warm it up again and go the other way around, unless it takes you 20 minutes to adjust the valves you won't see a noticeable change.

So here's my question, if you can't get an accurate reading while reading hot, then how do you verify the cold setting you chose is correct? Why do cam manufacturers even list "hot lash" settings?

Bottom line do it how ever you feel comfortable. But that's how we have done the race cars, and for that matter all of my cars for a long while now and never had a problem yet.
And for the record I never said run the car with loose lash, I set start loose to warm up the motor then adjust.

Set a cyl or two valves to the correct spec fully hot, as is driving it around for a while. After letting the motor COMPLETELY cool off, recheck the cold lash...you now know exactly how much YOUR combo expands....just set your valves tighter to what that expansion rate is.

My BBC with alum heads grows .007.

Tip....you may have to wait 2 days for that motor to completely cool off and assume room temp. You would be suprised how much heat these motors retain internally. Also, air temp makes a difference too....been cooler here latley, all my valves were .001 looser this time around.

Set a cyl or two valves to the correct spec fully hot, as is driving it around for a while. After letting the motor COMPLETELY cool off, recheck the cold lash...you now know exactly how much YOUR combo expands....just set your valves tighter to what that expansion rate is.

My BBC with alum heads grows .007.

Tip....you may have to wait 2 days for that motor to completely cool off and assume room temp. You would be suprised how much heat these motors retain internally. Also, air temp makes a difference too....been cooler here latley, all my valves were .001 looser this time around.

I have done it both ways, but hot lash is the best IMO. The all aluminum 707 in the race car changes almost .020, and not consitently from valve to valve (a reason you wouldn't want to base all on one cylinder). We use cold lash numbers on it to check, but set it hot. In a street car motor, with an iron block you are splitting hairs either way, so just do it how you feel comfortable.

I've been setting lash since I adjusted the tappets in my Grandmother's 6 cyl 58 Pathfinder - Sish! - 48 years.

Here's some things that I've learned over the years:

1/ Engine Temperature: You would be suprised how much heat these motors retain internally. In the morning, after an all night snowfall, my BB is the only car in the lot with no snow on the hood. I prefer the Block Warm not Hot to set the lash - Never liked the way Hot Tappet Adjuster Assemblies torqued. From my experience the "Cold/Hot Lash" varies with each motor and should be noted.

2/ Never loosen a "Girdle" when setting lash. Just slacken ONE Mounting Bolt at a time just enough so you can barely adjust one Polly-Lock. You would be surprised how much Rocker Stud Alignment affects Lash.

3/ If you have room above the keepers, I recommend "Lash Caps" as they not only protect the end of the Valve Stem and prevent the Roller Tips from wondering but also make setting the lash easier and the setting remains effective.

http://farm4.static.flickr.com/3371/3234547525_43e983d24e.jpg

Sure my 7000rpm 600Hp 460BBC makes one H*LL of a racket when cold on startup but after 20 minutes (which seems to take forever, $10 of gas and the Volvo 70S Fan cuts in), the engine has reached Operating Temp and the Oil Pressure Equalized, it's runs verily quiet and buzzes like a Nest of Hornets ;o)

PS: If you did not have the Lifter Bores Trued and run oversized Ford Lifters, I highly recommend that you use an Oil with Hi-ZDDP content (1200ppm minimum) in a FT Engine that has been Retro-Fitted - Consider the Forces associated with Cam Walk on the Lifter Needle Bearings ... etc and use a Strong Anti-Cam-Walk Device (NOT stupid Teflon buttons against a Stock Timing cover). Don't use Torrington Wear Plates but stack Drilled Impregnated Washers and Lube with drill hole into the front Cam Journal Gallery. Lock the cam to within .004" end play. I personally use a Donovan Cam Gear Drive but ISKY make a solid Anti-Cam-Walk Device. If your after Rev's Isky's light weight 7/16" Chrome-Molly Push rods are very nice. For the Street I like the Comp Cams 933-16 Springs that set up at 200/500lbs at the stock 1.88" BBC Spring Height and it doesn't hurt to drill the PSGR front Oil Gallery to lube the Timing Chain or Gears - Whatever it takes to run a SR on the Street - Just make sure you have the BRAKES to STOP IT ;o)

http://farm4.static.flickr.com/3415/3547432296_74412c8618.jpg
Original 70Z Body, 7000rpm 600+Hp 10.25 460ci SR MK IV LS4, M22/3.08 12 Bolt Posi - HWY Warrior. If you live in Northern Ontario, I don't worry about Road Conditions or Snow Plows.

I run the AR288-10/Crower HIPPO's but thinking about the Lunati 502A1LUN that would sacrifice RPM for Torque to quench a ride that is somewhat EXPLOSIVE with the M22/3.08's.

4 years on the mill BUT forget the Chin Spoiler ;o)

Thanks for all the input. I just finished up adjusting "cold"@.006 looser. I will run it tomorrow and re adjust warm if it sounds pretty loose.

Thanks for all the input. I just finished up adjusting "cold"@.006 looser. I will run it tomorrow and re adjust warm if it sounds pretty loose.


You did it the opposite way as it should be done. You will GAIN lash doing it this way. So, if you cam called for .020, and you lashed it for .026, at operating temp, it will be .032!!!

Too much lash beats the cam to death. If you are doing it because the engine runs better, then you have selected the wrong cam, and need to go to a smaller one.

http://farm4.static.flickr.com/3371/3234547525_43e983d24e.jpg


Got to love them Jomar girdles.....


http://i150.photobucket.com/albums/s86/wildman926/69%20Chevelle%20SS/Jomar.jpg

You did it the opposite way as it should be done. You will GAIN lash doing it this way. So, if you cam called for .020, and you lashed it for .026, at operating temp, it will be .032!!!

Too much lash beats the cam to death. If you are doing it because the engine runs better, then you have selected the wrong cam, and need to go to a smaller one.


Sorry I explained it wrong. :o I subtracted .006 so instead of .020 i set at .014 and .016 instead of .022