I am getting ready to fire up this 235 after sitting for 25 years, and i think i have all my ducks in a row with the exception of timing. I understand that the pointer lined up with the BB is TDC at #1, and i am looking for a good starting number/procedure to set initial, and a number to set total. I know there is a risk of great debate here for optimal performance, but i am looking for some base numbers just to run and assess this engine before it gets pulled, and resealed and painted.
I have a good Snap-On 12 volt adjustable light with rpm, and was thinking to hook it to a separate 12 volt battery, and then to #1 plug wire, as my system is 6 volts. Once i have it running:
1- with vacuum advance disconnected, what should my initial timing be, and at what RPM? 2- What should my total mechanical be, and when should it be all in? 3- and what should my total mechanical, and vacuum be, and when should it be all in?
Also, is there a straightforward procedure for getting this initially started. I am more familiar with the SBC, and SBF set ups, and I think the flywheel BB may be throwing me off a bit and causing me to overthink this a tad....lol
I will get that info tonight and post it, the number on the vin tag for the engine is XC45816, but i know that it is a different engine, still starts with XC but don't have a pic on my phone right now. This is assuming you are looking for the number stamped on the flat surface near the distributor.
The distributor vacuum advance line is connected to a point above your throttle valve on your Carter YF2100S (carb from your other posting). At idle speed you should have low or no vacuum so removing your vacuum line for timing is not necessary. Not a step in the shop manual anyway.
In case you didn't know - oil pressure and head temperature pre-checks: If you notice on Deve's website, at the bottom, there is a procedure to check your oil pump. I used a piece of rod stock and tapered to fit the slot on the pump. See if your oil pressure gauge works. Your temperature sensor is mechanical. You can very carefully unscrew the holder and gently lift up the gas-filled tube and bulb. Place in hot water and see if the gauge functions.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
Having been parked that long ago it should be plain old gasoline in the tank, no ethanol. Assume you plan on draining the tank, if they sit very long with 'E' whatever they won't have a tank left to drain.
BC 1960 Chevy C10 driver 261 T5 4.10 dana 44 power loc 1949 GMC 250 project in waiting 1960 C60 pasture art Retired GM dealer tech. 1980 - 2022
It's extremely risky to put gasoline in a tank that's been sitting that long, even if it's empty. Use fresh gas from a clean container like an outboard motor gas tank for the initial startup, and clean or replace the onboard tank. There have been numerous instances of engines running well after long periods of storage, and then developing sticky valves, bent pushrods, and even broken rocker arms from gummy deposits formed when gas from the tank dissolved old varnish deposits, which then ended up in the valve guides. It's happened often enough that I believe there's a tech tip here on the site warning about it. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Thanks for all the great advice, and i will be sure to refer to the links.
I plan on running from a jerry can full of clean non-ethanol gas on start up until i have a chance to look inside the tank, for now it has been flushed a bit with clean fuel.
In the pictures below, the numbers on the parts are as follows:
I hope I haven't broken the cardinal rule of "Know what your working on!". I assumed that this was a 235 due to the side cover, and year of the truck, but have not been able to 100% confirm as its a Canadian truck, and I haven't been able to find much info on it.
After pulling the distributor, I vacuum tested the advance can, and it is leaking internally and not moving the rod at all. The rod moves freely when i push it by hand so I am assuming the diaphragm is toast. Rock auto has been fairly good to me as far as parts accuracy go, but i am not able to find this part there. Any suggestions on a part number, and source for this?
Search Ebay for "235 Chevy vacuum advance". There are three of them listed this morning. They're fairly pricey, but scarce parts usually are. Be aware that you'll have to re-use the part of your original advance unit that clamps to the distributor housing and has the "octane selector" slot. There are two different shapes to the vacuum advance bracket available, but the only difference that will make is in the routing of the vacuum line. Either one will be sufficient to advance the timing properly.
While you have that plate removed, take some time to clean and lubricate the centrifugal advance system. That's the weights and springs under the plate which move the breaker cam forward as the engine speed increases. I use Lubriplate lithium base grease as a lube for the advance but a SMALL amount of high temperature wheel bearing grease will work OK. If you have a dial indicator, check the lift on each cam lobe. Most of the distributors I have checked have noticeable differences in the height of the lobes, which affects the timing between cylinders by changing the point gap. I remove the insulator in the side of the distributor housing and adapt the dial indicator plunger to bear directly on the cam. Good luck! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
The engine casting number does correspond to a Canadian 235. Interestingly, the 1112396 distributor codes to '54 passenger car with Powerglide for US service, and the date code is also mid '54. I don't have info on distributors used in the Canadian engines to know if they were different.
The original PN for the vacuum advance assembly is 1116076 for that distributor. NOS units pop up on eBay, sometimes for reasonable $. But, you should be able to get a replacement unit at several of the suppliers. By way of example, Chevs of the 40's has them: Vacuum Advance Control Unit.
Jerry, I found one on Jim Carter's website that looks the same (although its only a drawing) and is cheaper. If the only difference is vac line routing i can muster up the skills to do that. I did see the sludge inside the dizzy, sprayed it out several times and spun it with a drill to throw the junk out where i can wipe it, but the rest of the unit is tight. I will get some of the lubriplate you mentioned before i assemble.
Doug, thanks for looking into the numbers for me, I have struggled to find much info on the Canadian trucks. I will check out the link you posted as well. I am glad that this is "still" a 235 ..lol, as i had ordered several parts already. When I saw the GM cast above the engines i thought there may of been a chance of an oddball engine in there.
Another little detail, and this one's important- - - - -the grease cup fitting that's in the side of the housing has a spring and a plastic disc under it that puts pressure against the distributor shaft and keeps the shaft from wobbling. That wobble can affect the point gap and result in a rough idle due to timing changes between firing impulses from one cylinder to another. If the disc is missiing or worn out, the spring will wear a groove into the shaft. A small slice of 5/16" phenolic plastic round rod like Bakelite or Teflon makes a good replacement. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Thanks Jerry, I will take a look, when you say small slice, 1/8" or so is fine? is the grease designed so that you fill the cup and screw it on, you would bottom out the cup and the grease pressure maintains the contact to prevent the wobble? Or is it meant to be tightened/adjusted over time as the grease runs out?
Fill the cup with fairly stiff grease, and give it a twist at every oil change. The lubricator is a 2-piece assembly, with a part that threads into the housing, and a cup for the grease. A cup full will last several years, usually. Quite often, the grease is so gummy it has to be dug out with an ice pick or something similar when the distributor gets serviced. The male thread part of the grease cup assembly that threads into the distributor housing puts pressure on the spring, so all the grease does is keep the upper part of the shaft lubricated. A slice of plastic 1/8"-3/16" thick will last for several years of every day operation, as long as the shaft that it runs against is smooth. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
buoymaker, thank you for looking into this, so the XC647197, is actually just a C647197, I wonder what the X represents? You will see that even the original engine on the VIN plate shows an X.
So the 4G26 date code is July 26, 1954. The part number 1112396 corresponds with a 1954 with automatic transmission. So it’s a 54 dizzy, although very late in the production run. The 54 models ended their run at the end of August 54, factory retooled in September, with the first 55s rolling out September 30, 54. So if the date code was say August of 54, would have been a 2403 distributor for the 55 run.
That being said, the early 55 pick up trucks were essentially 54s I believe. What I don’t know is how long the first series were made before the second series 55 started down the line. I also don’t know if the first series 55 trucks used a 54 motor or the 55 motor with the 2403 distributor. While I know the truck line did have an automatic trans option, don’t know if that was available for all trucks. So while I am fairly certain it’s a 54 distributor, it may be an early 55 first series truck distributor.
Your distributor uses the following advance curve:
1116043- starts at 7 to 8.5 inches of vacuum and full advance is at 18.5 inches, the max advance when the vacuum advance is needed is 10 degrees.
1116076- starts at 4-6 inches of vacuum to get it started, full advance at 7.5-10 inches of vacuum, the max advance when the vacuum advance is needed is 7.5 degrees.
If you are tinkering, take the point plate off and make sure the advance weights are free, the springs are in place and the pins the springs are hooked to are tight. If there is a lot of gum, you can spray some carb cleaner and get it cleaned, then lightly oil the weights.
Uses the earlier short distributor cap 824735 (D-301) and the earlier pre 55 points, 1918148.
Points are set to .016, plug gap is .035. I don’t know what AC plugs you would use as I don’t have an ac catalogue. I have a champion chart because I run champions and so J12y or the modern equivalent j12yc or rj12yc for a resistor plug.
the Vacuum advance 1116076 is on back order at Chev's form the 40's, do you think that the extra 2.5 degrees will affect anything by going to the 1116043? Or should I stay with the 1116076 that Doug mentioned above? Looking at the curve numbers you posted it seems like there is a margin of error and it would work.
Stick with what you have. Remember, these motors were work horses. So they will run and run and run, even when not perfectly adjusted. Yes, my hopped up motors require a little more precision, but a stock motor, na, it was designed for reliability and ruggedness. Get it all cleaned up, make sure the lobes on the distributor are not rusted or rough, set the points to factory specifications, install it. Set the initial timing to tdc and get it started. Once started, you can tinker. These motors can usually take a few degrees of advance with today’s fuel. So if you want, get yourself a dial back timing light and start adding advance and see how the motor likes it. If it runs better and no pinging, you are good, if not, go back. No harm no foul.
