Gents... I have a '62 model 235 in my '49 1 1/2 ton. It has hydraulic lifters in it. I have recently pulled the head and had it checked and have now reinstalled it. I did a rough set by pulling them down to the tappets and hand-rolling the engine a couple of times and then pulling them down again to remove all the excess free play. I used Dave's method of setting 1/2 the valves with #1 at TDC and then moving to #6 at TDC and adjusting the other 1/2. That worked to get the truck started and running but it still seems to be running a bit rough. I am looking for advice on how to do a fine tune on them since my '49 book doesn't know about hydraulic lifters and I think using a feeler gauge in 'em is not the way to go. Any advice would be most appreciated.
RE: Adjusting Hydraulic Lifters Thanks for the info. I am awaiting the arrival of a replacement vacuum advance that turned out to be shot. It hopefully will arrive tomorrow. Once I get it installed I plan on warming up the engine and making another pass at the valves. I had used the same basic procedure that Nate outlined so I guess I am on the right track. I wanted to make sure I was not missing some trick to make sure I get it right. I sure hope this cures my miss and smoothes her out.
RE: Adjusting Hydraulic Lifters Be aware the method of ' zero lash then 1-1/4 turn more ' is actually in many GM service manuals but isn't smart as it results in a tight valve in nearly -every- case . I assume you know that both NAPA Echlin and Standard Ignition both make the vaccum advance mechanism for old Chevy 216/235/261 engines. There _must_ be -NO- vacuum to the advance when the engine is idling ~ if there's vacuum @ idle , either the vacuum hose is connected to the wrong port or the carby is one of those wierd ones , test the various vacuum nipples untill you find the one that gets a vacuum signal as you open the throttle - this is what prevents "flat spots " off idle . Open your spark plug gaps up to at least .035" and check to ensure you've got a white or blue spark , a yellow or orange one means new condensor and maybe points (ask and I'll explain how to test points with a voltimiter) , after all those are good if still a yellow or orange spark the coil is dead , get rid of it NOW . I hope you get the miss out of your engine soon as a sweet running 235 is truely a joy to drive . -Nate
RE: Adjusting Hydraulic Lifters I did use the valve adjustment method of "remove the lash and add 1/4 turn". I also verified visually that the valves were not in any way being opened by watching the valve stem as I adjusted the 1/4 turn. You can see the stem if it is starting to be pushed down. If so, I would back them off so no movement was visible. I was using the TDC on Cyl 1 and then 6 to adjust the two halves of the valves per Dave's method. I pulled and cleaned all the plugs because they were all black with soot, not oil or fuel. It seems to be running real rich but I haven't been able to take it out and drive it since it won't run reliably. The points, condenser, wires, distributor, and coil are all brand new or newly rebuilt by NAPA. The head was checked, magnafluxed, cleaned and the exhaust/intake ports milled to match the milled manifolds. I put in all new gaskets. I changed the oil which was obviously contaminated with water and gas. I understand that all the idling and short runs in the driveway have probably collected lots of water and gas. There is a steady drip of water from the tailpipe at idle but there is no antifreeze or gas smell in this water so I am assuming it is condensation since we have such high humidity up here. When I had the head off I didn't see any evidence of water in the cylinders and it doesn't seem to need to have the radiator topped off after several months of fooling around. The local NAPA store couldn't find a listing for the vacuum advance but offered a rebuild service for $45.00. I went to Chevy Duty because they have one for $29.95. It should arrive today or tomorrow. I have tried to adjust the carb but 1 1/2 turns from all the way in seems to be about right, but the truck sure seems to run awfully rich all the time. It doesn't even like to be choked to start. Any other ideas? It's getting closer and closer to pleasing me, but still no cigar.
RE: Adjusting Carby Black soot is fuel fouling , I assume you're opened up the spark plug gaps to .035" -minimum- (NEVER trust the pre-gapping) and have the timing spot on . Each carby is different but 1 - 1/2 turns out from lightly seated is a -lot- of idle fuel mixture , go DRIVE the darned thing to clear out all the carbon and then when you come back and it's idling , pop the hood and take your tiny screwdriver from your shirt pocket (don't want to shut it off after the drive , dig ?) and turn the idle mixture screw _clockwise_ about 1/4 to 1/2 turn , if the engine speeds up , lets it run a few moments and turn it in again , just a little bit and keep on doing this until the engine either stumbles or begins to slow down again , what you're looking for is the highest -steady- idle speed . them back the screw out 1/16 to 1/8 turn but NO MORE and take another test drive , you may well find the idle speed has creeped up , this is fine , re adjust it with the idle stop screw on the throttle arm but DO NOT touch the mixture screw again !. You can also use a vacuum gauge connected to the port in the intake manifold , set the mixture to the highest -steady- vacuum reading then unscrew it by 1/16 ~ 1/8 turn . Carbys DO NOT need constant fiddling ! once set they should be good to go for several YEARS , if the engine begins to runpoorly , do a TUNE UP always beginning with valve adjustment . The water dripping out of the tailpipe is usually an indication of the low quality fuel we get in America these days , thank a tree hugger for that -and- the groundwater pollution caused by MTBE and other crap added to the fuel . I hope this helped . -Nate
RE: Adjusting Carby You always seem to help, Nate, even if it just confirms what I am already doing. I do have the plugs gapped to .035". I always use a gapping tool and don't trust factory gapping as the plugs can get banged around in handling if nothing else. My problem is that I still can't drive this thing until I can get the engine running halfway reliably. I am close to that. So far it will only run for a few minutes before it starts acting like it is out of fuel and it dies. Then it is a #$%ch to start for a while. I am moving it back and forth in my driveway to warm it up. My driveway is a couple of hundred feel long, so I can get it up to 2nd gear before I have to stop. Once I get so I can trust it better than that, I will take it out on the road. I got it out once a couple of months ago and got it about 2 miles before it quit and the wife had to come tow me home behind the suburban. x( I thought the water was nothing serious at this point. I sure want to get it out and completely warm it up and make one last pass at the valves. I am taking the vacuum advance in to get it rebuilt. The one I got from Chevy Duty was the wrong one. That's my fault, however. I have a 45 degree instead of a 90 and the coupler arm won't interchange.:-(
RE: Enging Quits NO problem my freind , I'm one of those few who -likes- a wrench in my hand... Vintage vehicles only please . It runs bad & quits as it gets hot ? sound like bad condensor or points to me , even if the condensor is new as I've had plenty bad ones , right out of the box . Want to take a walk through the ign. system with me and sort it out ? . How much voltage at the HOT side of the ign. coil , ign. key -on- , points _open_ ? . You're going to need a multi meter do do these simple checks , get a $10.00 one from Harbor Freight or SEARS , skip the fancy digital ones and get an analog (dial typ) one , O.K. ? doesn't need to be expen$ive but the $3.95 ones can mess you up unless you know what you're doing . -Nate
RE: Enging Quits I'm an electronics specialist and Field Applicaitions Engineer so test equipment for electronics is not the problem. It's more a need for tribal knowledge of some of these things like what the voltage should be since those kinds of things don't often appear in the manuals. I got it running last night at perhaps the best sounding I have ever had it. I drove it up and down the driveway a few times trying to get the timing set better as it was sputtering on acceleration quite a bit. It then started acting like it always had and then just died. I spent another hour readjusting the valves a little better, fiddled with the carb and just couldn't get it to start. I finally gave up and decided to follow a hunch. I pulled the gas gauge sender out and stuck the tank. It showed about 1/2" on the stick. Next I shot a flashlight in the tank and found out that the fuel intake was high and dry. I don't remember who it was on this forum that said something a few months ago about these things needing gas to run. I think I am onto something and will try that next. Sometimes it's just the little things that count.
Hydro Lifters I have an old 49' chevy that was my fathers. The only thing I know about the motor is it is a 235 out of a later model truck. It has a ticking in the top end of the motor that I am guessing is valve clatter. The motor was rebuilt back in 2000' and probably has had about 5,000 miles on it since. How do I tell if my motor has hydro lifter or just standard lifter. Is the process first explained about finding top dead center of #1 adjusting those valves and then #6 and adjusting those valve correct for my motor. This motor has never had valve clatter till now and I am very new at this motor. Also in this motor do I need to add a lead additive to the gasoline. I am currently buying gas with no ethanol at a station that sells it. Any help at getting me into the making this thing run great would be appreciated. Ben
Ben Follow the sold liter adjustment regimine then adjust the points and timing , get it warmed up and running , if it runs well and the valves click like an old sewing machine , you're good to go . Remember : you must rotate the engine before adjusting the valves on each cylinder ! . they can only be properly set when the cylinder is @ TDC .
