The Stovebolt Site Forums The Shop Area Engine Shop hydraulic lifters

Hi guys, I had my 235 chevy engine rebuilt; bored 40 over, rings, cam bearings, etc, etc; to the best of my knowledge the block is 1958 & I installed an 848 head on it; My problem is the engine had no oil to the rockers; I ran a 1/4” line from the gauge outlet to the rockers & solved the problem but the engine ran rough & all attemps to remedy it was not successful. Also when I adjusted the valves 1/2 turn from 0 clearance the engine would not run ( backfireing & no power, so had to back adjustment off to 0 clearance; engine then ran pretty well but sounds like a diesel. I then pulled the lifters & found that 4 of them were not pumped up, so do any of you have any ideas? Sorry about the long message, but trying to explain the situation. Thx for your help. Richard

You probably have some plugged-up oil passages that are not allowing enough oil volume to the oil galleries to keep the lifters filled. Did your rebuilder take all the oil gallery plugs out and brush/flush all the passaged? That's vitally important with any engine, but it's really necessary on one with hydraulic lifters.

If new cam bearings were installed, it's also possible to obstruct certain oil passages by not getting oil holes in the bearings lined up correctly. You might be looking at another engine disassembly if the lifter-filling problem persists. Try taking the pushrod cover off and spinning the oil pump with a 1/2" drill motor, and watch the lifters to see if oil is being supplied to them properly. I'm beginning to suspect an incompetent assembly of the lower end of the engine by the rebuilder.
Jerry

A 58 block huh? Does it have a steel line behind the side cover? The reason I ask is that GM changed the oiling system slightly for the 59 model year. So you could have a 58 casting date for a 59 model year car/truck. that block might not have the steel line as 58 was the last year for the steel line. That may or may not be a consideration here. May or may not be part of the problem, or it may be part of a much larger problem as Jerry suggested above, poor assembly of the lower end. Were the rear most lifters pumped up? Which lifters were collapsed? Any chance you used newly manufactured lifters as opposed to NOS GM or RNOS aftermarket (25 years old or older)? For whatever reason, the new lifters on the market have been a bit of a challenge. A close friend of mine runs a machine shop. Did a 54 hydraulic motor for a customer. Three sets of new lifters before he called me. Could not get a complete set in that motor that did not have a few that collapsed shortly after start up and run. I gave him a set of NOS GM lifters and that was the end of that. This issue with the new lifters has been going on for some time.

Hi Jerry, Thx for your reply; I will contact the machine shop to inquire about that; & will also try the drill to see if any difference.

Here's some good info.

http://www.canadianmilitarypattern.com/1960%20235-261%20Engine%20Manual.htm

My initial thought is that your machine shop installed the drilled head bolt in the wrong spot. Secondly, Your 1/4 oil line is taking away too much of the oil pressure needed for the cam/lifters. They used an orifice to restrict the oil to the valve train.

Hi dragsix, This is the 2nd time I have assembled this engine. The first time it was rebuilt evrtything was fine ( new hydraulic lifters & cam; but after 5 or 6 k # 6 cyl dropped to 55 pds of compression so I disassembled it & used another block that I have & installed the 848 head & have had the problem ever since.

So what is the casting date for the block and the head? Anything stamped on the distributor pad? The reason I ask is that in 55, GM was still making two different 235 blocks. One block for stick motors and one for automatic motors. The stick blocks could not be fit with hydraulic lifters because the galley needed to supply those lifters was not drilled. In other words, no retro fitting hydraulic lifters to those blocks. The blocks made for automatic equipped cars came fitted with hydraulic lifters so was drilled for that use. You can use hydraulic lifters or you can retro fit solids. It would not be totally unheard of to find a 55 pass car engine in a truck. Probably pretty common. This distinction ended in 56 when all car blocks were drilled for hydraulics. I am not sure whether that was the case with all truck blocks. So identification of your block and head would be good information to have as to what year you actually have.

What year distributor? If you don't know, just pull the cap off and get the part number and the date code and we can see if there is an incompatibility issue. I would be surprised but you never know. If the block is in fact a late 55 through 62 235 block, the distributor for those motors is one ending in 2403. There may be some variation if it is a truck motor but I would have to pull my delco remy stuff and double check.

Before you pull the motor and take it apart, you might tinker a bit. Jerry recommended that you spin the oil pump. The way that I do it, which does not mean its the only way, is to get a spare 2403 distributor. Grind off the head in the gear pin, knock the pin through and remove the gear. Then gut the rest of the distributor until you have just the shaft and the cast iron housing. Now you have an oil pump tester and engine pre-oiler. I have heard recommendations to use a screw driver and all other manner, just not for me. Manually bring your motor up to TDC for No. 1 cylinder. Take off the cap and put a chalk line on the body of the distributor where the rotor is pointing. Remove the distributor. Remove the side cover. If there is a steel line remove it. Install your new fangled tool making sure the tang on the shaft fits into the slot in the oil pump. Chuck the top of the shaft into a drill and spin. If the oil pump is working properly you should start to hear the drill labor a bit and you should see oil coming out of the threaded boss at the back of the lifter galley, rear cam bearing boss. If no oil is coming out then that is a problem. If its a later block, 59-63, there will be no oil line as those blocks directly feed the rockers through a drilled galley in the block and head. So you should see oil from the rockers (remove your copper line and plug the head).

I would probably pull a lifter and spin the oil pump just to see if any oil flow in the lifter bore. If not, it all points to having to pull the motor and really investigate the problem.

BTW, the drilled bolt that you hear so much about is actually a bolt and a plug. So if you had a 55-58 block, and the head went bad, and the service replacement was a 59 and up 848 (for the record, the 848 casting number started production for the 56 model year, I have an 848 head cast in late 55 for the 56 production model) and you were going to use the 55-58 rocker set up on the 59 and up head you had to use the drilled bolt and plug. I have an nos bolt and plug if anyone wants to see one. What is the difference you say, well there is a drilled orifice in the head for the rocker feed. In 59 Gm increased the size of this orifice in addition to changing how the rockers are fed. GM also altered the rocker connector by pinching off the copper tube, and modified the rockers. a 55-58 rocker has a groove on the inside of the rocker that directly intersects the spit hole in the rocker. The 59 and up rockers the groove is off set. GM was trying to create a sort of high pressure system for 59 and up. So if you use the 59 head on a 55-58 block with 55-58 rockers, you get way too much oil spitting, not dribbling, out of the rockers. The drilled bolt and plug corrected that problem and supplied the correct amount of oil to the 55-58 rockers.

There's no need to butcher up a distributor to turn the oil pump- - - - -just go to a hardware store and buy a piece of 1/2" steel round stock and grind/hacksaw/file a tang on the end of it. Spin the pump with the shaft clamped into the chuck of a 1/2" variable speed drill motor. I've been priming V8 and 6 cylinder Chevy engines with a tool like that for almost 50 years.
Jerry