I read the valve setting procedure on www.speedprint.com/deves50/valveadjust.html, as instructed by Mr. Nathan Hall. We cleaned the flywheel very good and it has no BB mark, only a tiny triangle. Viewing through the flywheel window, I set the pointer to the triangle, setting the timing with a gun. Does this sound ok? I want to get it correct because my next step is to set the valve adjustments - which relates its instructions to the BB mark. I would appreciate any suggestions/cautions as I do not wish to deal with the adverse consequenses of a job poorly done. Kent
The triangle is the TDC mark , there should be a hole drilled in the flywheel about 1/4" away from that with the BB in it , it is hard to imagine no BB , it's pretty small and can easily be covered up by rust and accumulated grease . remove the flywheel cover and set the engine to where the triangle is at the lowest point then wash the exposed flywheel with engine de-greaser and a stiff brush . once all the marks are clean , rinse them with aerosol starting fluid (ether) then alow to dry (about 30 seconds usually) and use the butt end of a paper match to work some white paint into the triangle and paint a circle around the BB's hole if you can find it . For ignition timing , use the gun to set timing to the triangle then do the drive and ping test in thrid gear to set the final timing as that's far more accurate anyway . -Nate
The following is what Son (good eyes) found for us - (since the image is upside down, rotate flywheel 180 degrees in your mind so as to read rightside up: U|C o 5 -blank area- <|. The last figure, the triange is separated by about 1 1/2 inches from the small o (the U|C o 5 is close together). The small o is indented and is not a protuding BB. Is the small o the BB mark to set the valves with? What is the ping test in third gear? Also I noticed that the timing setting, with the triangle mark, varies with the rpm. Do I need an rpm guage? Thank you. Kent
O.K. , you can use a long phillips screwdriver in the # 1 spark plug hole whilst slowly rotating the engine by hand to ascertain which mark is the TDC mark , use that to set # 1 valves then just do each next one in the firing order by watching the points break as you gnetly turn the engine in it operating direction with the dist. cap off and rotor out whilst you stand on the bumper leaning over the (blistering hot) radiator . Isn't this fun ? simple tho' . The top gear ping test it when you adjust the timing then go for a drive and get the truck up to 30 MPH on a flat bit of road in top gear (3rd. if you have a 3 speed 4th. if you have a 4 speed , dig) then suddenly _stamp_ the throttle to the floor ~ if it pings , pull over and rotate the dist. back about 1/16" , if it does _not_ ping , pull over and advance the disributor about 1/16" and try again , keep advancing it untill you hear it ping then back it off only just enough to where the ping stops . this is GM's recommended method of ignition timing , it's in the shop manual I keep telling you to buy The BB is prolly in the O you found , it doesn't protrude at all , it's hammered into a very small hole drilled into the flywheel . It is normal for the idle speed to vary as you twist the dist. thisa way and that . Use the ping test then set the idle as slow as it'll go and see if a mark , _any_ mark lines up with the pointer when you try the dynamic timing light . You _ARE_ using the window over the starter correct ? we had one guy a few years ago who was trying to time his 235 using the window on the manifold side of the engine ad he was going crazy not seeing any timing marks no matter what . Use the ping test if possible as it's more accurate anyway . I hope this helps ? . I was stuck in my truck in traffic all day and I'm bushed . -Nate
For setting valves the most accurate method and the one used by nearly every racer is this: turn the engine over until the EXHAUST valve just starts to OPEN, then set the intake on that cylinder. Now turn the engine until the INTAKE valve starts to CLOSE, now set the exhaust on that cylinder. It sounds like you have a book that I'm sure shows the valve layout on your engine but you can see which valves line up with an intake or exhaust manifold runner(port). The method discribed above assures that the lifter is on the heel of the cam on the valve being adjusted which is what you want.
Re: Valve Adjustment Procedure Just so Evan but ; Most of the folks on this list are not mechanics so we try to make as simple and easy as possible . FWIW : his point is : setting valve lash on the _flank_ of the cam lobe rather than the heel of the cam is far more accurate and is indeed important when running a high speed engine in a performance vehicle . if you understand it , it'd be smart to do this on your StoveBolt too . -Nate
Valve Adjustment Procedure Thank you for you help. Yes I have the valve layout and yes I have the shop manual. I will study the instruction(s) and do the one that seems to make the most sense and less error probability (to a novice). Kent
RE: Valves & Hot Missing As it turned out I've been having a worsening hot miss so last night I stopped work and popped the rocker box off to take a peek , since I deleted the fan I no longer take the time to check the valves one at a time engine off , rather i use the old flathead method of running the engine at about a 400 RPM idle speed and slip the feeler gauge in as they're ticking away ~ I found one tight inlet valve and loosened it up to .010" , that helped a goodly bit . It appears the intake manifold is again leaking vacuum ever so slightly at the nearest head joint to the tight valve . -Nate
RE: Valves & Hot Missing I thought I would check the valves while at the 450 idle speed, after a thorough warmup of the engine. I wanted to see if it felt right to me (running the feeler guages in/out in adjustment), vs the off-engine check we had been discussing above(and I listening). I will probably do both to double check my work, from different angles, so to speak. I like the idea of engine-off, but as a novice, I might work so slow that the engine could cool before the job gets done. The manual says that from cold to hot could vary as much as .005, a significant amount. I appreciate the help. Kent
RE: Valves & Hot Missing No problemo Kent ; One tight valve will cause bad idle . A couple of tight valves will cause poor starting . Since my quickie tune up it now idles cold again when I 1st. fire it up in the wee hours of the morning . I found a nifty old vacuum gauge in a junker F-rd and will soon add it in the under dash braket currently occupied by the voltimiter , since I finally added a correct diode the Delcotron alternator is charging well , even at 650 RPM idle speed so that gauge is now redundant .(I suppose it always was being as the ammeter works fine) I love those old color coded vacuum gauges , green is idle , red is decell and yellow is cruise . -Nate
I set the valves on the 235 today. I let it run for 30 minutes at idle, then drove it around on the hiway for 20 minutes. It was hot enough to melt my plastic hood holder pole, the end sitting on the engine. I tried to set the valves while it was running, but it was like trying to catch a fly. I assume there is a special tool instead of a screwdriver to make it work. Finally I set the valves with the engine off, per the instructions noted in the 1st email of this series on valve settings. It was pretty easy this way. After getting it all done, I started the engine and tested the valve setting that way. All but one felt ok, so I cut the engine and readjusted it. There were 3 exhaust valves that were really far off, I wondered how they exhausted the gases, with such a wide gap. Every valve was at least a little off, having to reduce the gap setting on each, both intake and exhaust. I can tell the difference in acceleration now. I wonder why it ran as good as it did with it being off. Interesting, I could hear the engine go slower as I tightened the valve too much (when the engine was running). For my vehicle, the valve adjustment was a must to do, knowing what I know now. KentC
Kent ; It takes a ' just so ' screwdriver that's short & fat to fit the adjuster screw correctly plus of course , doing it once (or a few thousand times) makes it far easier . Remember to re-check them in a couple hundred miles or so . It still ran O.K. because it's a good design , I hope you now go and spread the ' adjust your valves ' gospel as few seem to understand how important it is . You should use an old broom handle to prop the hood up ~ no plastic ! (yuk) , I like to carry a long(ish) one and prop it on the frame so it has less chance to slip if you should bump it with your elbow... Didja bead blast the springs ? that's why they won't hold the hood up , a common error . Chevs Of The 40's sells nifty cheap hood spring stretchers.... hook the sring to your trolly jack to extend them then install the tool , release the jack and install the hood springs , remove the tool and sell it on E-pay . -Nate
I did use a fat and short screwdriver, but still it was very difficult for me. I use a pole to hold up the hood because my spring slot is rusted out and I need to fix, not a priority now. Plus the hood sticks up some near the windshield. I will fix both, but for the present will use the pole. I have printed off the last suggestion. Again, thank you for the easy way to adjust the valves. And thank you other men for your help. KentC
RE: Valve Adjust TOOL OOPS ! dummy me forgot to mention : If you can find a w i d e blade screwdriver , file it so the very edges have a tang that hangs down over the outer edges of the adjuster screw , this makes if not slip out as much . I don;t have one but they're nice , I doubt they're made anyore . Maybe a cheapo gakset scraper would work , one with a 3/4" wide blade and short handle ? . If only I could post pictures... Chi-Town Joe (my 76 year old Diesel mechanic) has one and I could show it to you guys . -Nate
RE: Valve Adjust TOOL II Well cool ~ the Matco tool guy came by yesterday and I showed him one of the screwdrivers I wanted to use and he said ' I can order that ! ' so we'll see in a week or so if maybe a vintage valve adjusting tool is still available or what . -Nate
RE: Valve Adjust TOOL II It would have been nice to have Sunday. Son worked the open end wrench and I operated the short & fat screwdriver. It was still like catching a fly, over and over. I would think a screwdriver with a cover over the flat end would do, then only downward pressure is required to keep it on the adjusting screw. But looks like you have it by the balls now. KentC
Tune up The old 53' sure runs better with new points, plugs, valve adjustment and timing set. There is a noticable difference in going up hills and accelerating at 45+. But even still, with my 1BBL carb. the mpg on fuel is outrageous - me thinks below 10. What about the vaccum device, the timing accelerator, bolted to the distributor? It sit for 45 years, unused, in a dry climate. Thanks for the help. KentC
RE: Vacuum Advance TEST O.K. disconnect the vacuum advance tube at the carby and slip a bit of clean rubber hose over it , now start the engine and let it idle , suck on the hose whilst watching the dizzy , it should rotate a tiny bit and the engine should pick up speed . it did ? good , now suck on the hose then put your toung over the end of the hose and see if it holds the vacuum ~ it does ? good , your advancer is O.K. . I doesn't ? too bad ~ there's your poor fuel milage and a goodly bit of power loss too ~ get a new or used vacuum advance unit and test it before installing , it should hold 21" of mercury indefinately . If you can get any old vacuum gauge out of a junker or buy a " fuel pump tester " new or used , conect it to the nipple on the side of the intake manifold _below_ the carby and see what it reads when the engine is hot idling ~ should be over 18" , if not , carefully loosen the dist. clamp and rotate the dist. whilst watching the gauge , move it untill the vacuum peaks and the engine begins to miss , the needle will also begin to jump as the engine misses , now back it off a bit to get the highest _steady_ vacuum , don't be upset if it only goes to like 15" of vacuum ,mine did that untill I fixed the intake to exhaust and cylinder head leaks , a long laborious procedure . The primary thing to look for is : highest _steady_ vacuum @ idle . -Nate
RE: Vacuum Advance TEST Oh yes ~ I forgot to mention : check and ensure there is NO vacuum signal at the advance pipe @ idle ~ some replacement carbys have two or more vacuum ports and it is very important that the vacuum signal only comes on after you open the throttle (" ported vacuum ") If it has vacuum advance @ idle , hunt around untill you find the other hose nipple and use that . -Nate
