Technical 235 Chevy milled head no valve adjustment

I milled my 235 head and now there is not enough adjustment in my valves. Can I raise the rocker arm shaft the amount I milled the head or do I need shorter push rods or shorter lifters? This is a solid lifter engine. I looked in my old manuals and searched all over and couldn't find an answer. I see plenty of posts about milling the head but none talk about losing valve adjustment only ensuring the valves are not contacting the pistons.

 

Curious, how much did you it them milled?

 

Some shim the rockers, Melling makes push rods and lifters, I am not sure if they make them in shorter lengths.

You can have custom push rods made but it is an expensive proposition.

 

Inquiring minds what to know how much that was.
You should be able to make some spacers out of flat stock once you make the patterns for them. For that you should be able to set the rockers on a sheet of card stock and press down and get and imprint. It's been over 40 years since I had one of those apart and I can't remember if any except the one with the oil p***age are different or not.

 

It was 90 bucks to have it milled. took about 30 min and shaved about .060 off. Only one rocker tower is different with the oil tube. I'm going to make some sheet metal spacers for under the rocker towers and see how it goes.

 

I think buying custom push rods might be out of my budget on this engine. It might be time to drop something else in it as Ive about machined out any more rebuilds on this crank and block. Ive had the car for about 20 years and the only reason I go out of my way to keep fixing this block is because its registered to the engine block. still haven't figured out how to change that in California without putting a blue tag on it.

 

The shim can do it. Just use something fairly soft, since you are decreasing the inner diameter of the circle. That means the sides get forced into a narrower area. I have heard of stands cracking on other engines. Note these are not the full half moon.
https://www.hemiperformance.com.au/...-020-030-x10-each-suit-slant-6-big-block.html
https://wheelfront.com/shop/product/ford-shim-kit-rocker-arm-pedestal-m-6529-b302/
I didn't see any for the 235.
https://catalog.elginind.com/engine...mponent/a7c2053d-f23b-4193-938e-976df682987d/

Custom pushrods will work too. Check the inliner guys and see if this is common and they have on the shelf solutions.
You could also dis***emble the heads and grind the valves shorter, but the keepers limit this. Considering all adjustment is gone, that may not do it.

EDIT: If the valves have been redone, they tend to 'sink' into the head, which sticks up more on top. Your last post indicates this additional tolerance stacking might be it.

 

235 Chevy engines don't have a tower like that. They sit flat on the top of the head. The slant six is pretty much a completely different engine. Yeah I cant find any kind of product made for the 235 to correct the issue. I see plenty of shims for other engines. I just don't understand why so many have milled their heads on these but no one has commented about needing to make adjustments to the rocker towers.

 

Ah, my mistake. Sorry. If they are a flat tower to head, I don't know why not.

I did a bit of searching and didn't see this come up either. The rockers are the same (solid/hyd), so a mix of parts shouldn't do it. Might go back to the valves being taller, the head skimmed and it all adds up.
They sure look like they should handle 0.060 normally.
https://store.fillingstation.com/de..._19341962_ROCKER_ADJUSTING_SCREW_NUT_SET.html

 

I've run milled heads that have been cut enough that it eliminates the relieve between the intake and exhaust valve pockets. Never had any problems. The push rods I use are Melling MPR 32. There are probably different lengths for some of the other lifter styles.

 

The valves & seats have likely been ground several times, sinking them deeply. Also, when milling Chev 6 head more than cleanup, the intake seats are supposed to be recessed a like amount. The preferred method of raising compression on these engines is popup pistons.
We just used fender washers to shim the rocker ***'y up.

 

My '54 is same, it has serial number of block used in ***le, not hull.
Luckily I have OO's purchase do***entation where back in '54 dealer typed up both numbers correctly, but CA DMV used block serial for registration.

There is a form to to correct this.
I don't recall there being any issue in maintaing your current plates.

Gimpy would be the man to ask.

 

Buy a couple of these and put any engine in that you want. Keep the old engine around if you ever need proof of ownership...it's not illegal to replace an engine.
SERIAL NUMBER CHEVY ID TAG CHEVROLET DOOR DATA PLATE CUSTOM IDENTIFICATION USA | eBay

 

Post a pic of the rocker set-up so those that don't play with 235 can see what valve arrangements your playing with...


...

 

Pics here.
https://losangelesmachineshop.com/gm-235-1953-chevy-truck/#prettyPhoto

Fixing an error on a ***le
https://www.dmv.ca.gov/portal/handb...ments/correcting-a-vehicle-description-error/

 

Smith Bros …… shorter push rods.

 

From what I have seen, the spacers need to be moon shaped, small at the ends thicker in the middle, with the same shape and size as the original stand is.. If not, the rocker shaft won't set steady or you can deform it or the stand. These are for a Mopar, but you can see how they are shaped.

 

I had a weird random thought would lash caps gain you enough height on the valve?

 

isn't that backwards?

 

I think so, but trying to visualize all this in my head makes my giant brain hurt. I wondered if too many valve grinds over the years might have sunk the valve seats enough to add to the problem. Though it seems like that might have mainly only affected the exhaust valves.

 

@Joe H That was my mistake too. These have a flat to the head pedestal. Here's one of the pics I linked. It needs a flat spacer under the pedestal.

@ClayMart If the head has been shaved, the shaft moves closer to the cam, which means the pushrod extends higher compared to the shaft. That along with valves being reground which also would make the valve tip higher compared to the shaft would cause the shaft to have to raise to keep the same relationship. A lash cap would just raise the valve tip even more.

 

Contact Rocker Arms Unlimited in Northern California and ask if they have adjuster screws that will help your situation.

 

Another possibility might be "resurfacing" the valve contact end of the rocker arm. It would probably cost you a new head gasket, but shortening the valve stems is another option.

 

Thanks for all the different input. The engine head on the 235 is 4 inches top to bottom unmilled. I have a little more than 0.030 taken out. I put some spacers under the rocker towers yesterday but they were not tall enough to get adjustment back as I tried to go on the low end of a spacer. I'm going to put some bigger spacers in today and see what happens. It just hit me that I also have three new valves in the engine and there's a chance that those could be a little long causing some problems after milling the head. This engine did run with the new valves before the head was milled. I'm still mostly confused that I find very little mention of this kind of issue on the 235 after milling especially with all the older do***entation I have about 235s.

 

A long, long time ago, I bought a '54 Corvette cam from the Chebby dealer. Had my 235 bored and the head milled 0.125". Put the thing together with no lash compensation and it ran great! What did I do wrong to make this work?

 

You thinking it runs great and it actually running tip top are two different things. The 54 corvette engine was a full pressure hydraulic lifter engine. The only way that cam worked was that it went into another hydraulic lifter engine. Hydraulic lifters are a little more accepting of being out of wack without making a ton of noise and were probably on the tight side if you didn't notice. They probably were beating the heck out of that cam and valve seats. The 235 I'm working on is a manual shift solid lifter engine and it only likes the lifter adjustment right on the money, anything else and it wont start and you will hear every valve and lifter slapping.

 

hobbyip, thanks. As my weak memory serves me, it was a '54 powerglide block and head. I think those were hyd lifters?

 

Yup, 53/54 Glide engines were hyd.

 

My first car was a '53 two door sedan with a PGlide. Had a '54 PG two door . Also had a '55 first series 1/2 ton with a stick... not sure if that was hydraulic lifters. Not sure where I got the '54 block/head that I built with the new Corvette cam from the dealer.

 

Grind the cam so the base circle is smaller. [lowering the lifters]
The added benefit is the engine goes "rump rump rump"