The Stovebolt Site Forums The Shop Area Engine Shop 1960 C10 with 235 and Solid lifters

I have a mostly original 1960 C10 Chevy pickup with a 235cu engine. The engine has over 100,000 miles and is in need of an overhaul. A few questions:

I am almost 100% sure the engine has solid lifters. Research states the trucks had them, but the cars had hydraulic lifters. Am I correct?

Can the original head be converted to use hydraulic lifters or should I start looking for another head with the hydraulic lifters?

I have been told that it is a good chance the original head is cracked because “those” engines tend to have this problem. Is this true and should I be worried? If so, is this another good reason to look for another head?

Any help will be greatly appreciated.

…Russ

Hi Russ,
Not sure why you want to use hydraulic lifters.
I think the head is the same, either way... but the oiling supply from one type lifter to the other is slightly different.
Someone else who knows more about this might chime in.
If it were my engine, I'd take the head to have it checked first and stick with the original configuration.
Jerry

Russ,

I understand that the later 235 blocks were drilled for the hydraulic lifter oil passage no matter if they had the solid or hydraulic lifters installed. If you are contemplating replacing your solid lifters with hydraulic, you need to confirm if your block is set up for hydraulic lifters.

You will also need to change your cam, I believe, as the cams are cut differently.

The head will work either way.


Kurt

The difference between a solid lifter and a hydraulic engine is in the oil passageways in the block, not the cylinder head. There will be a large-diameter hole drilled from front to back through all the lifter bores on the hydraulic-lifter block to supply them with enough oil to keep the plungers pumped up. Trying to drill a non-hydraulic block accurately is almost impossible, so if your block isn't a factory-drilled one you'll need to find another block. I believe the 1958-62 blocks were all drilled for hydraulics whether or not they came from the factory with solids.

The hydraulic-lifter camshaft will have a different lobe profile, so you'll need to purchase a new, not used hydraulic cam and new lifters to match it. Once a cam and lifters are run together, never swap lifter positions, or try to match up used parts from diffrent engines. They will wear out almost immediately due to wear patterns not matching.
Jerry

Jerry, just thinking out loud,

But I would think the hole could accurately be bored in the block for the lifter oil gallery by inserting a guide in each lifter bore in turn as you pass through it. The guide could be made from an old lifter with the right size hole in the side.

What do you think?

Kurt

If you look at a hydraulic lifter block, they were drilled half way through from the front and then from the rear or vice versa, and the holes are offset in the middle (close is good enough).
I have toyed with the idea of making a drill guide that bolted to the front and rear of the block to guide a drill. I even bought a drill bit for this job.

It would require a deep-hole drill jig bolted to the block similar to what's used to make a gun barrel. The process could be done on a big lathe with a long bed, with the drill bit turned by the headstock, and the block set up very precisely on the carriage. The setup time and labor cost would far exceed the cost of purchasing a factory-drilled block, as long as they are available. Just because it's possible to do something doesn't mean it's a good idea if other methods of getting the same thing accomplished are possible.
Jerry

I was originally wanting to drill 216s for hydraulics.

Hmmmm- - - -that's an interesting idea. What type of oil pump do you have in mind to supply enough volume and pressure to support that type of setup? Who would grind the cams? Maybe use an early Powerglide 235 grind?
Jerry

Jerry, most people misunderstand hydraulic lifters. Once filled with oil they just recycle the oil inside them self, unless they are vented with hollow push rods or slotted push rod face that I discussed in another post.
1950-52 Power Glide engines ran the same low pressure splash system, as a 216, with hydraulic lifters, with no problem, so a 216 oil pump should be no problem.
Yes a 1950 to early 54 Power Glide cam would fit right in, or make a good regrind profile.

After teaching lifter principles for 40+ years, I believe I can converse about them with a bit of understanding. Lifters are in a constant state of leakdown, otherwise they would pump up and force the valves open, killing the compression. When an engine stops with a lifter on the high point of a cam lobe, the lifter slowly bleeds down to its fully-collapsed position due to valve spring pressure. Within a few cycles of the cam lobe after startup, it pumps itself up to eliminate any clearance, then it expands or contracts during running to compensate for thermal changes in pushrod length. There must be a slight, but measureable flow of oil through a lifter for it to function properly. I used a weighted tester and a stopwatch for many years to test lifters for acceptable leakdown rates, including stovebolt lifters from PG engines. The adjustment procedure in the service manual sets the lifter in a partially-compressed position to align its internal oil passages, and also allow for expansion or contraction of the lifter's overall height without bottoming out or expanding fully against the retainer clip that keeps it together. The total available travel distance of the plunger is just under 1/4" on most lifters, and the normal running position is slightly less than 1/8" fron the topped-out position. There must be enough oil pressure to replenish any lost oil while the lifter is on the base circle of the cam between valve openings. Under thrust from the lobe for the fraction of a second while the valve is opening and closing, the lifter acts like a solid because the column of oil trapped between the lifter base and the plunger will not compress.
Jerry

All correct Jerry, except the oil that bleeds past the piston is not lost externally on a 235. The oil is caught by the groove around the piston and directed, through a hole in the piston, back into what I would call the reservoir, ready to drop back down through the check valve, into what I call the working area, when the spring in the bottom pushes the piston back up.
This is where having some type of vent comes in to play. If all the air is not correctly bleed out of the lifter when installed, the air is trapped in the reservoir. Then just as the lobe is starting to let the lifter down and the inertia is sending the oil to the top of the reservoir, what is ready to go through the check valve to recharge the working area is air, making a soft and noisy lifter. This is what gives high RPM lifter noise. Once the engine is run at an idle for a short bit the air bleeds back past the piston back into the reservoir. Venting clears up this common problem. I discussed venting in a previous post.