The Stovebolt Site Forums The Shop Area Engine Shop HOWARDS M4F CAM VALVE SETTINGS?

This is sort of a poll question as to what is the proper valve setting for the Howards M4F solid lifter cam. I have researched this subject extensivelty and I still am not convinced I have set the valves correctly. Hundreds of these cams have been sold by Howards and other vendors so you would think someone could tell you. Lets just say may confidence level is not high after communicating with the usual suspects, looked in old motors manuals for the corvette settings, called the cam company, sent them e-mails, looked on the cam card. You know the drill. So I am asking you who have actual experience with these cams in your beloved 235/261 engines, with settings (after break in) and WHY you like your final settings, (higher vaccuum, engine runs cooler, too much valve noise so I changed it, better gas mileage, etc).
Tim

I don't understand why you do not have confidence in the cam grinders recommended clearance. It is established as part of the cam design, depending on ramp profile, seat time, wear characteristics of camhaft and valvetrain materials, expansion factors, etc. It is certainly a safe starting point. There is always going to be noise with a solid lifter engine. Tighten up to reduce the noise, and you risk burning valves and/or wearing out the cam. Too loose and you will have a power loss because the valves aren't doing what the camshaft is telling them to. Any possible "preferences" that folks may have can be due to differences in their feeler gauges.

I just put one of these cams in my rebuilt '54 235. I haven't put enough miles on it yet to have to reset the valves. The way I set them (after talking with Patricks) seems to be fine as far as noise, engine temp., etc. (Patrick) told me to use the #1 ex valve as the guide.. bring #1 piston up to TDC then mark 12 o'clock on the balancer. At this point you could set 2 valves (I have this written down in my manual out in the garage but, can't remember exactly right now). Then rotate the engine till balancer is at 4 o'clock set a couple of valves, 8 o'clock 2 more, etc. has worked out ok thus far.....
Stingray

I posted a week or so ago about changing the lash setting on the M4F in my 261. The recommended setting on the cam card of .014 and .016 worked best for me. Trying the stock 261 setting resulted in poor performance on my engine.Our other 261 is a stocker with the original "Corvette" cam as used in 261's. The factory listed lash of .006 and .018 works best on that engine. The Corvette cam and the M4F are similar in duration but the M4F seems to have a more aggressive opening and closing profiles.
I have found on the M4F, the most accurate settings are done one valve at a time, the lash checked when the companion valve on the same cylinder starts to open.Using the traditional method of rotating the engine until the number one cylinder is in firing position ,then adjusting #1 intake,#1 exhaust and so on leaves a wide variance in clearances. The settings are done warm, like after a 1/2 hour run.Once set correctly the valves stay in adjustment for a long time. The Howard cam is busier sounding than a stocker, but the valvetrain mechainical clatter is vintage hot rod music.

This is a very timely post. I just did my valves last weekend using the "set the #1 intake & #1 exhaust .... then rotate one revoloution. I don't think they are quite right yet. I need to get my vacuum gage out and see what that shows. I think I'll have to try it again using Tony's method.
One question on using the vacuum gage, do I disconnect the vaccum advance from the carb and plug or do I leave it? I'll be using the port on the intake manifold for the vacuum gage. I would like to try to use the vacuum gage to check the valves, timing, ect. Thanks

To help in getting an accurate adjustment, I trim the feeler gauge tip to about 1/4 inch wide using a sharp sheet metal shears.Even with refaced or new rockers, it doesn't take long for the valve stem to wear a slight depression in the rocker end that contacts the valve.Hopefully your valves are not recessed into the head , this throws off the rocker geometry, resulting in more noise and wear.Even if the seats are replaced ,its no guarantee the valve stem heights are close to correct unless you check them yourself.
I have lots of free time,lol, so I can check the valve lash on one cylinder at various degrees of cam rotation before the cam opening flank closes up the lash and starts opening the valve.As I stated earlier, the tradition valve adjustment techique varied the lash by at least .005 depending on where you checked it. On my engine setting the valves one at a time etc,keep the lash as constant as possible.The engine is happy, more power and less noise.Does all this fussy crap matter on your vintage engine?Maybe not ,but you'll never know unless you try.Oh yeah , if you take too much time messing with the valves, the engine will cool down some and maybe affect valve clearances as you go through the procedure.
46forme, I have never used a vacuum guage on an after market cam.It may be better to do the valves on a modified engine with feelers as the highest vacuum at idle may not mean much when the engine is reved beyond the original stock limits. Try it and post the results.

When setting the valve lash on a new engine that hasn't run yet, its cold during the adjustment. The howard cam card says to set the valves .005" tighter than the specs, to account for break-in. Does this sound right?

Tony, how did you set yours? Did you set #1 exhaust when #1 intake was open, then spin the motor until #1 exhaust was open and set #1 intake, then go to next cylinder in order? Or did you bounce around between cylinders?

Thanks

Chip,I go in order, from front to rear.My truck has a later car starter making it easy to spin over the engine with a pushbutton hooked up to the starter.You can jump around if it makes it simplier and you have more brain cells than me, I get so confused, lol.Yeah that break in lash setting sounds familar.I would rather run hydraulic lifters, but so many guys have reported problems with them on 235/261's.Hydraulics supposedly run with zero clearance,giving all the lift and duration designed into the cam.
When you think about it, we spend an awful lot of time messing with engines that are pushing the limit with 180 hp from 235-261 cubic inches.This is fun , not to be taken too serious.
Chip again, how's your engine coming along?did you get the machine shop straightened out?

Its a long story. I should have started videotaping this disaster from the start of this project in May 2001. I could have broken it up into a TV series on public-access cable. It would have been a hit. Welcome to the next episode of "As the crank turns".....

So machine shop #2 keeps my engine for 8 months. I get it back 2 weeks ago thinking its ready to build. Then I inspect the parts and find out that the shop did a minimal job.

Head: Valves lapped, but head not vatted or cleaned in any way. Head still dirty.

Block: Water passages, oil gallies, threads full of crud.

Crank: Paid for balancing, don't think it was done. Slight impact damage to #1 main that may polish out.

Pistons/Rods: No loc-tite on pin clamp bolts. No balancing. One rod still has lockwasher on pinch bolt. Other 5 do not.

Cam: Appears that the new aluminum cam gear is pressed on incorrectly. Aluminum metal shards visible on cam snout where cam was pressed into gear.

I thought about going to the shop and complaining, but what good would it do besides [censored] machinist and me off? I can't trust him to rework these parts correctly.

A friend had a Mitsubisi Eclipse head done at another shop in town. They did a great job on it, so I brought them my 235 head. One machinist there knew what the head was when I brought it in. He was friendly and knowlegable about the 235s. If they do a good job, I'll bring them the bottom end and camshaft to inspect. I'll keep you guys posted on what happens.

Sorry for the rant....

Thanks again guys,

chiphead.

Oh, I forgot: The new machinist said that the '55-62 engines must use shimstock in their main bearings. Is this true? Am I in the twilight zone?
do-de-do-da-do-de-do-da.....

Chiphead,
Yes, Cam card sais .005 tighter for break in. However when calling cam company last year - man there said to not do that? Recently I hear that Howards Cam has sold out a small machine shop somewere in the midwest is making the cams now.

Has anybody else used these cams or experience setting them up "lash wise"?

Tim

I called Howard cams a week ago looking for a M4F because Patrick was out out them. They told me that they have not made them in some time and though the specs may be the same technically Patrick should not be calling them Howard Cams. He also said they were thinking of starting to make some agian.

The cam I got from Patrick's has "Howard's Cams" on the snout. My cam must have sat on a shelf for awhile. Some of the lobes have slight surface rust. How do I clean this off?

Try some ultra-fine emery cloth, oxide base. Or some fine rubbing compound for polishing car paint. Whatever you do, go slow. You might also take it to your new machine shop, they should be able to clean it up with little effort.

Playing with valve setting have recently changed mileage from 10.79 to 17.86 mpg. So I am on the right track. Thanks for all who responded. I think there is at least 20 mpg in there somewhere.
Tim