After "mucking about", as our friends across the Atlantic put it, with C4 engines for 23 years, every once and a while the dang things come up with a new ailment, usually announcing the fact with a previously unheard noise. To save others from having the same ailments possibly appear I thought that it might be a good idea to document the fixes. The first time that this happened was after the engine had been in my avatar car for about a year, and a strange, low pitched knock started coming from the lower rear of the engine. It sounded like a loose main, but usually a main won't make noise at low speed, and this was most prominent at idle. turned out that the six bolts that hold the flywheel to the crank had started to elongate their holes, and the flywheel was shifting diametrically with each cylinder firing. Not a whole lot of option for increasing the bolt size, but I did go with grade 8 bolts, and self locking nuts. To take the torque load off the bolts, I drilled and reamed for 6 3/8" dowel pins between the bolt holes, and so far, that has solved the problem. I have never (well, not for a long time anyway) been one to "drop" the clutch to see how much tread can be removed from the rear tires--but once the clutch is fully engaged, I have been known to show no mercy. Over a year ago I stopped at a fellow's house, where Model A Ford owners meet one night a week, and on leaving wound out first and second gears, knowing that none of their engines could match the revs. When I got home, and was putting the car in the garage, I realized that there was a knocking noise at idle. Since it had been a number of years since the flywheel incident, the noise didn't seem quite the same, but I assumed that the same thing had happened again. I put the car away for the winter, and got busy with my '28 Chevy coupe, putting an Eaton blower on the diesel engine that I had installed earlier. Finally, when I couldn't think of any other excuses to use, I drug the roadster out of storage and started checking things. Holding the flywheel from turning, and rocking the crankshaft back and forth, revealed no play, so the engine was torn into, since i intended to put a set of higher compression pistons in anyway. In the process of all this, I could find nothing that I could blame the noise on.Finally, just before I was going to put the pan back up, I grabbed the cam, to see if there was excess play in the timing gears. There wasn't, but the cam would move back and forth about 3/16"--there was the noise. The end play in the C4 cams is controlled by a bronze plate that is trapped between the rear of the timing gear, and the front cam bearing. Nothing holds the gear on the cam but a Woodruf key and a press fit, and the right amount of play has to be created by pressing the gear on just far enough so that the bronze plate is free to move, without slop. The GM "engineers" cleverly designed things so that the helix angle of the gears tries to force the cam gear off the cam--these guys were absolutely brilliant--NOT! I pulled the gear the rest of the way off--it was tight--cleaned things up, and pressed it back on with Loctite. Evidently the combination of a 50# oil pump, much stiffer valve springs, and high revs, caused the gear to work its way off. I considered several other mechanical ways of better securing the gear, but lack of room, and the cam being hard cause these to be impractical. I used the strongest Loctite available, and if the problem reoccurs I will only have to take the front of the timing case apart. Picture of how the gear has to be pressed on--it can't be driven on, as there is nothing decent to resist hammer blows, is below. Like the gal said when her nose started to bleed "If it ain't one damned thing, it's another" Herb
Hi All, Does anyone have any advice in regards to mating the chev 4 to another gear box? I am putting one in a lighter chassis (Standard Flying 10 or Morris 8 as I have both and the chev chassis is a lump) and am thinking of using that gear box so I can keep the running gear as is. If this falls into the too hard basket, has anyone had any success with cutting down the torque tube? I saw the question asked but couldnt see an answer sorry. Cheers Damo
I have not done the Chevy yet. But I have mated a Plymouth four and a Dodge Bros Four as well as a Lotus 907 to a Ford gearbok that came with the 2 liter four. Worked well. I have also bolted a Ford top loader to a Chrysler 392 as well as a Packard V8 and a Pontiac. Swaping gear boxes isn't hard but a mill is very handy. The stock steel bellhousing is a big help as it's so easy to adapt to another bolt pattern. If you want to PM with any questions that I can maybe answer, feel free.
Since the C4 bell housing is pressed from approximately 3/16 sheet steel, it is relatively easy to modify it to take other transmissions, by removing the existing rear wall and substituting one that matches the front pattern of the "new" transmission". Important points are that the finished front and rear surfaces of the finished housing be parallel within about .005", and that the central hole that locates the transmission is in line with the center of the crankshaft within about .002" This is best done with machine shop equipment, by a decent machinist, although there was a series here on HAMB where a cast bell housing was modified with only a drill press and a hand held grinder, as I recall. Certainly, because of the pressed steel construction, it is an easier job than a housing that is cast iron, due to the ease of welding. As for shortening the torque tube--since this has been asked a couple times, and my only answer is to say that the rears are a POS let me explain what would be involved in shortening one, The drive shaft itself would pose no particular problem,and anyone who could do a Ford shaft, could do a Chevy. The best method would be to cut off the front end and machine a new spline for the U joint, but there were plenty of Ford shafts done by cutting some out of the middle and welding back together. On the Ford rear the drive shaft tube, and the axle tubes both unbolt from the centersection of the rear, so shortening the drive shaft tube is usually done by removing the excess length from the tube a short distance in front of the rear flange, then rewelding after checking that the pieces are in line in a lathe. The Chevy rear has the torque tube and axle shaft housings riveted to the center section, making it impractical to take apart. The best place to shorten in this case would be right behind the front of the tube where the bell shape containing the U joint is. Since lining up in this case would strictly have to be by eye, the inevitable misalignment would cause the least trouble. I have said it before, and I'm getting tired of saying it, but why use a rear that has WW1 style brakes, axle shafts and drive shafts that were constantly breaking with a stock 27 or 36 HP engine?? The material of the shafts is , like so much else on the car, the cheapest crap that GM could get away with. By going with a modern transmission, you will not only have a much stronger transmission, but also one that shifts much, much quicker--and is quieter to boot. Herb Kephart
Hi Guys, Thanks for the answer. I think I am better off with the Standard diff and running gear. In regards to the rear brakes Herb, I am using it for racing. December 1939 is my cutoff for what I can use. The other reason being is that it is going to be used for circuit racing I never like overbraking the rear. With skinny tyres I cannot jump on the brakes in an emergency without spinning. I prefer a 70/30 split. Just my experience that is all. Thanks for the advice anyway but due to the bellhousing looking like its easy enough to play with, I will look at adapting the Flying 10 one on. That way I can keep the rear as it is and it will match the front brakes. Another question if I may... I have three blocks. One has the rods on display along the side of the block. Which year did this finish and are the heads interchangable? I have three blocks but only one head. One of the blocks has the pushrods on show and the other two dont. Cheers Damian
PUT DOWN THAT TORCH. I would not remove the transmission locating part of your original bellhousing. It has what you want in the pilot hole for the front bearing retainer. If it's to small you may be able to bore it or you can often turn the retainer to fit. You can locate off of it and fix a steel plate with proper bolt locations by using counter sunk screws. Or maybe just drill it and weld the nits like I mentioned. Whatever, You have a good, pretty close factory center now. Save it and save yourself some time.
Damian The only blocks that have the pushrods hidden are 1928. If the blocks have the push rods exposed, and the distributer is in between cylinders 2 and 3 they are 1926 or 1927. Earlier than 1926, the distributer was driven from the rear of the generator, which was driven from the timing gears at the front of the motor. All heads interchange, but the early ones with the single exhaust port are prone to cracking if overheated. Rich-- you are quite right- perhaps I didn't put enough emphasis on the fact that it should be done in a machine shop. However, the bell housing ends up too long for most modern transmission input shafts--hence the need to cut at the rear. What I did was to locate the bellhousing on a plate with a couple of (added) dowel pins, then put the assembly up in a lathe and get the transmission mounting hole true in both planes. Left the plate in the lathe, but removed the BH and did my evil work on it. remounted it on the plate, and faced and bored the new rear area. After mounting the modified BH on the engine, I indicated the hole relative to the crank and found that by opening up the mounting (bolt) holes 1/64" I could get it near perfect. I then transfered the dowel pin hole locations to the flywheel housing to keep things in line. I guess that I made it sound too easy the first time around. Herb
thanks again herb....as to why? for me its because the car i'm building is period. a toyota rear in it would make it worthless to me.so far the newest part is 1936... my car will never see pavement. there are 100s of kilometers of dirt roads around here to race around with no hassles of cops, inspections or insurance. if i brake an axle , oh well i have 8 more to choose from. i fully understand your opinion tho , and if it was my only car to drive it would be an easy choice.
As you can see from my picture, I am using Lakewood and other blowshields, mostly, for bellhousings. Blowshields are required by the SCTA. I have been using the four speed transmission from a '72ish 2000 Pinto/Capri. The blow shield is about 6 inches deep. The Chevy bellhousing about 4 1/4 + another 1 and 3/4 cast onto the block for 6 inches. On my Plymouth I had to space the Pinto trans back because the input shaft was to long. Same with the Lotus 907. Not true with the Dodge. I guess the Pinto parts are getting kind of old and hard to find in any kind of usable condition these days. But maybe some time spent with a tape measure and a bunch of transmissions would be a good way to spend a day.
Here is an interesting thread on running a '28 Chevy engine in a T chassis, complete with a link back to the HAMB from a fellow who appears to be undertaking such a transplant. Most of the T guys aren't thrilled, naturally, but I still find it interesting and useful. One thing I'm not getting, though, is why T guys like the Chevy crank and rods, but we are all discussing replacing the Chevy rods with Ford Model A rods. You'd think the T guys would be going straight for the A rods. -Dave
Dave, I'm trying to remember, but I think that there's very little modification that needs to be done to use the Chevy rods in a T... funny thing is that Gerber was using T rods in his Chevy!
Herb, Dave was asking about counterweights on the VCCA forum... and it reminded me to ask you to post pics of your truck block project and those counterwieghts!!! Thanks again for taking the time for my dad and me- it's always GREATLY appreciated! Take care, Bill
Bill- too bad we don't live closer--we could brainstorm more often! Took a while to find this--it is a 223 crank, but the looks and principle are the same First, if crank is to be drilled for oil pressure, do that before counterweights are put on--it is easier to set the crank up then. Flame cut counterweights are welded to crank, then machined on sides and OD. Crank will probably have to be straightened, and most certainly need to be balanced. If the engine HP is to be increased to any extent, bolt flywheel to crankshaft and drill, ream and insert hardened ("dowel") pin between each bolt hole. I have a B&W pix of the 170 crank from the engine in my avatar, finished--but will have to find and scan it. Herb
Thanks Herb! So Brad54 set up an opportunity to check out a property that had some older cars on it. We pulled in this morning and the first thing I saw were '28 Chevy doors... after the introductions, I asked about any other early Chevy parts and just about tripped over a '23 engine/tranny- SWEET GOOGALLY-MOOGALLY!!!... There were 5-6 Chevrolet chassis (all '26-'28) and two pre '26 engines!!! Suffice to say that the two ealry blocks (both rough) and the '28 truck engine (no, not a 223, but it was a truck chassis) are crammed into the back of my poor 4Runner! Everything was pretty rough, but hopefully one of the early blocks is good (the '23 has a crack runnning between the two bolts/rivets on the generator side of the engine) and that the '28 engine is savable (full of water, but also full of oil). All-in-all a great day! And of course, NO ONE brought a camera, so I'll have to shoot some pics of the spoils that are killing the rear suspension of my daily.
So, as we are pulling Bill's engine out of the truck chassis, I keep bumping into this 28 Sedan Chassis. Of course it bears further investigation. "Hey, this thing is solid". So, in the spirit of my signature line...guess what I made a deal on?
Ok you chevy 4 guys, I like this posting and since cars are my hobby I like to follow interesting subjects. The chevy 4 was alway,s a mystery to me, I never really seen or heard much about them in my early hot rod days. They seemed to do pretty good in racing but were kinda run over by the Ford crowd. So the question thats been bouncing around my brain was 'who' was responsible for its design. Was it Louis Chevrolet, and/or some others? It seems it was a pretty good design but hampered with some casting problems. Just curious I have searched some but havnt yet come up with any good answers. ?????
Gee Bill- I think that you are just trying to have a larger mountain of old stovebolt crap than I do--but congrats on the score!! Those two holes that have the crack sound like holes for the small screws that hold the rod troughs- so if there is an obvious crack there, examine the area around it - inside and out- because it sounds like the area took a hit from a rod looking for a breath of air. If you have ANY place to store it, gather up any sheetmetal parts that look to be usable---good trading material over on the VCCA site Herb
I think the only Chevrolet-designed Chevy engine was the original six. Chevrolet and Durant had a falling out over the direction the brand would head (Chevrolet wanted a large, sophisticated, prestigious car; Durant wanted a cheap Ford fighter), and Chevrolet left to go back to racing Fords. I don't know for sure, but I kind of expect Boss Kettering was behind the 490 engine design. I swear Alfred Sloan touches on it in his autobiography just before describing the "copper cooled" debacle of 1923. -Dave
Herb, Thanks for posting your counterweight info both here and on VCCA. I keep expecting hot four guys to pop up over there, but there doesn't seem to be the speedster contingent there is in the MTFCA. Given the ratio of good chassis and engines to sheetmetal in the early Chevy world, you'd think it be the opposite! -Dave
Dave-- The answer is that you can BUY speed for the Ford, but you have to MAKE it for the Chevy--that was the reason in the 30's and is still true today. Herb
Dave- Have you noticed that the last posts on two of the threads on the VCCA site are mine... and are over TWO WEEKS OLD? Herb- I've pretty much run out of room... ! 39cent- get John Gerber's book Outlaw Sprint Car Racer- you'll LOVE it! The only aftermarket head that I have heard of was patterned by Gallivan for Chevrolet (marketed through Frontenac, I think) and was based on the Olds 3 port design. Gerber had lots of trouble with it and modified it to suit. Later, he bought the pattern, modified IT, and made his own head.
I have and old product flyer from Larel and it offers a head for the Chevy from Frontenac. Can't seem to locate it right now. Ron
Hi Gents, Was chatting to a gent recently who told me that I need to retard (iirc) the timing after start up so it doesnt backfire. I have no reason to doubt him but as I will be building my own special, is this much of a concern? I wont have an original steering wheel that is all and if it is the case, either I have to put a starter tit in the engine bay or rig up something from the cockpit. Cheers Damo
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