Mac, what lifters and how would you keep them aligned, is there room in the lifter galley for alignment bridges between the intake and exhaust lifters of each cylinder?
I found some Saturn lifters that were very close to the '28 bore. There should be enough room for alignment bridges (the Saturn bridges are on the top of the lifters), but you'd have to make new ones (the stock ones don't have the same spacing). That was after a quick search- like I said earlier, if we can get the '28 measurements/etc (like helpful tidbits of info) together and posted, it will help when we're looking. Also (asking out of sheer ignorance) do any companies list their parts by measurements as well?
Mac and Red Rodder The modified in my avatar has a 28 chev truck 4spd in it works great as a 3spd has no syncros and is fun to drive. It has the reverse "flipper" on the stick. My 28 motors both were from 1tons and a standard chevy-muncie patern t-5 will bolt on if you trim the input and collar. You have to drill and tap the two bottom bolts in a new spot. and use a s-10 clutch disk with the fine spline hub.
Fellows, there's a '28 Chevy engine, trans, radiator and firewall on eBay right now. Somebody's old sawmill rig. Just thought you might want to know. -Dave
HMMM, wish i had spare cash at the moment, I had to horse trade for what i've got. I am looking very hard for a good radiator surround though. I thought I had one but it turned out to be a an early 28 aa capitol truck shell which is the same as a 27, not a 28, oh well.
Pistons for Chevy fours On a stock motor there is 3 from the center of the wrist pin to the top of the block, when the crank is at TDC. In the picture below from right to left the pistons areCast iron-skeleton piston '26-'27, 1.875 center of pin to top, Aluminum stock-'28 1.875, 261 Chevy truck, 2.000, Hercules JX4-C2 & JXC-OOB (Zolner Piston Co #153) used in John Deere and Massy-Ferguson combines-2.125 pin to top ( started out using these, but the last that I got a price they were over $100 with a discount EACH!) and finally, on the left, homemade 2.250 pin to top. There are a couple other possible candidates, '55-'57 International (now Navistar) Black Diamond, 264 CID 6 cyl, and also 270CID GMC 6 cyl. Both of these have a stepped top which might give some turbulence which the Chevy could use. All of these above are 3.750 bore, except for the 270, which is 3.781 The other option for more compression is a longer rod. The Chevy rod is 7.375 center to center, and weighs 30 or 32 ozs., depending which forging it is made from. Ford A rods are longer (7.500) lighter (26 ozs) and better material. In fact, the whole engine is made from the cheapest material that GM could get away with, so the more internal pieces that come from other sources, the better. I am not sure how long the Durant rods are, but the rods that Bob Rufi used were 8.250 center to center, and came from a Curtis OX-5 V8 aircraft engine. These engines, and parts for them, were common as surplus after WW1 The likelihood of finding a good stock cam is about the same as winning the lottery. I had mine built up and reprofiled to 30-70-70-30 timing, and made flat mushroom tappets. The stock tappets, with the bottoms radiused, defy all logic Early timing gears were steel gear- crank, cast iron gear- cam. In the '26-'27 era they tried a fiber crank gear and a cast cam gear. (F*****G brilliant!) then in '28 went to a steel crank gear, and fiber cam. '28 cam and tappets will not fit earlier engines. The cam and crank are on 4.3125 centers, and the gears are 26 and 52 teeth. Teeth are 10 diameteral pitch and 14 ½ deg pressure angle (size and shape of teeth.), lead of helix 38.27 cam, 19.14 crank. A pair of straight cut spur gears, 23 and 46 tooth, 8 diametrical pitch will work in place of the helicals, but be noisier. Pressure oiling. The only place that oil can be put into the mains is by drilling and tapping holes in the main caps, but in reality this is the worst place from an engineering standpoint, as the oil should enter at the area of least load- the top in the case of a main bearing, One way around this if you are using insert bearings is to cut a groove in the block so that the oil entering the cap runs around the outside of the insert to the top, where a hole in the insert allows it to go to the journal, Since all three mains are different diameters and lengths, finding off the shelf, modern, inserts will prove a chore, especially the small diameter front main, and the center main, which has a thrust face on front and rear. I made all the bearings in my engine from soft aluminum, which works fine IF you run an oil filter, and have the crank journals welded up with the hard surface rod that is used on diesel truck cranks. A late 50's- early 60's 6 cylinder Chevy oil pump is easy to adapt. Line coming out of pump goes to full flow filter, from there to three mains. Throw away all stock plumbing and rod troughs. Run a couple extra quarts of oil in the pan to ensure that the pump pickup screen (which will end up slightly higher in the pan) stays covered under all conditions. All for now. I can't figure how to get photo to come out page size, but if you click on the thumbnail it will enlargea poota person I ain't Mac- I think that there isn't enough room between the cam and the top of the case for a roller Unsafe6-Rod details (what little there are) in a day or two Herb.
ebtm3---thanks for taking the time to elaborate on this information. I've had a '28 engine for years, and always tossed around the idea of doing something with it, but haven't as of yet. By the time we're done here, I think that all of the correct info should be put into a "California Bill" style speed manual for Chevy fours.
Just thought I would pass along what my dad told me about the ‘28 he did in ‘35 when he was in high school. He used the Olds head, and Durant rods, which have both been mentioned. His rocker arm selection were Nash. I don’t know which Nash or what year. As Nash made both ohv 6’s and 8’s in those years I don’t know which rocker was used. Just another idea of what was used back then.
Nash rockers, oh boy, i think the scrap drives of wwII took what was left of those would be something to look in to, though I cant remember the last early nash I saw around here
Thanks ebtm3 for the pics and info. cant wait to see your project rods. What kind of piston crown would generate turbulance without pinging, dished mabey? Again thanks guys for sharing all your schoolin' on these little mills.
------------------------ No idea where you'd find a '23 Olds head nowadays eek, but if you did and wanted to run one, one solution for the rocker-arm deal might be adapt some modern aluminum roller rockers. I have know idea what it would cost, but Harland Sharp.(www.harlandsharp.com) to name one manufacturer,.offers custom-made rocker arms for 'one-off', 'odd-ball' and 'antique' engine restorations'. Mart3406 ================================
mart3406, 3 port heads are still out there- they seem to be easier to find down under. The issue with adapting modern rockers is finding one that is 3 1/4" center to center:
How is the truck bellhousing different from the passenger car version- do you have any pics? Thanks, Bill Herb, I'll have to get a pic of the roller lifters I found- looked like they would work, but who knows.
Have a road trip to Norway http://vcca.org/forum/ubbthreads.php/topics/149971/Mystic_Chevrolet_engine_head_p#Post149971 There is a complete engine likely available.
I went through some more piston catalogs. Nothing special found. In case you found a suitable rod that has a 30mm eye, then there is a couple of options to be used from diesel engines. At least from Ford and Caterpillar. There is actually two types of those MB pistons. The other one is flat top and the other is stepped top. What is actually the desired piston top shape to get the mentioned turbulence effect in a Chevy engine? Here is some must documents for the Chevy four builders. Most of you folks most likely already have these. http://chevy.oldcarmanualproject.com/shop/1925/25crmindex.html http://chevy.oldcarmanualproject.com/1916_28parts/cp4cm00.htm http://chevy.oldcarmanualproject.com/shop/1927/27crmindex.html http://chevy.oldcarmanualproject.com/chevyresto/28index.htm http://chevy.oldcarmanualproject.com/chevyowner/28cim00.htm There is also a good long technical thread about rebuilding a -28 engine in the VCCA chat. Search for "school is in session". I've promised to make an edited pdf version of it, but it is still badly in process. I just hope I'm able to arrange some more time for it in a near future.
========================= Fins would be way cool in my opinion. You could have the fins starting on the sides of the cover and continue them up anover the top siurface in kind of a radial pattern. Another idea - maybe not really do-able - at least not easilly do-able, might be to more or less copy the general design and fin pattern of the early 'Vette factory cast cover's, but with the word "Chevrolet" done in traditional Chevy-style script in the center in place the word "Corvette" That'd relly get people scratching their heads! Anout carbs - somebody mentioned maybe using a pair of Holley 1904's from a 144 inch Ford or simmilrt. I think those would be neat too, particuatly if you got a pair with the glass Holley-script floatbowls. Either that or a pair vintage cast bronze 1-bbl updraft carbs from an marine engine of that era and then polish or chrome plate the bronze. Icidently, you can still find old cast bronze updraft carbs fairly esilly if there is an old, established marina or a boat graveyard near you as bronze was used for marine engine carbs for years after car manufactures all switched to aluminum and pot-metal Mart3406 ===================================
From the sounds of it, the Chevy 261 pistons would be the easiest way to go (at least in this country). They're still available, and are not outrageously priced; plus, it makes me glad that I bought that set of standard size TRW forged 261 pistons at a swap meet a couple years ago.
Somewhere (in a galaxy far, far away), I remember seeing an article about a vintage Chevy nut who made his own performance pistons for Chevy fours--I think it was in a late '60s/early '70s R&C. The piston crown shaped a combustion chamber when it came to TDC, similar to a set of 11.5:1 pistons I once saw for Vega engines.
Bill im not shure if the bellhousings are different but the patern on the car 3spd I have is tiny. I think the T-5 deal would be an easy one, the pressed steel rear section of the bell has a quite large flat area to mount to,cut,drill ,tap or weld to. I think the 261 piston is probobly the easyest and I have modifyed a set of rods. My concern is the small end is getting a little thin after being bored .080" for the pins. I wish the 261s had the same pin size as a 235 then it would be a bolt in. I have done lots of head porting experimenting on stovebolt 6s with siamesed ports and Im confident the mods I have done to the 2 port 28 head will easily meet the little 4s air needs to 4500-5000rpm with some more cam. ebtm3 counterweights cut on a waterjet would be a way to go? how thick of plate would you use to get the weight needed? I guess any counterweight is better then none right? I really need to dig out my parts and get my camera bussy.
Unsafe, Thanks! If you do get those counterweights cut, find out if you get a discount for a bigger lot... I'm sure a few of the guys would chip in for a set! Wish I could get a good pic of the ports in the Olds head- it was a much better design than the '28 head (although the comment Herb made earlier about using the cheapest materials, etc helps me understand why). Heathen, bushing sound like a good idea on the pistons!
By all means yes, if you get a discount for a larger lot put me down for a set, and by the way, I have ported a few small block ford heads (mainly the standard square ports to use boss oval headers) what is the method to porting these 28 heads? On the fords you port to size and blend smooth over about 3/4 of an inch in, same with the intake manifold. Different technique on these? As far as the con rods, you using ford As or the chev? I thought the ford rods had a bit bigger little end.
I am simply flabbergusted at the number of posts this topic has generated. I'm glad to see the interest. A few quick comments on things that have been written so far- No worry about pressure oiling of any type causing oil to leak around rocker shaft etc. as there is NO oil above the block deck on any of the engines. The 490 (the one that was built to compete with the Ford T) had no cover, and the rockers were oiled whenever the squeaking got to the driver. All others had a felt pad loose on top the rocker assy. which could be oiled thru holes in the rocker box. Plenty adequate for a car not in daily use--I use this system on my 3 port head with homemade aluminum rockers. One place that you will get oil leaks on the fours is where the tappets come thru the top of the crankcase, and are exposed. I made aluminum pieces with seals fron hydraulic control valves, which helps--altho no C4 is ever going to be completely dry on the outside after running Mac.--You asked about parts by dimension- go to an automotive machine shop and ask if they have any old Sealed Power books that they will give you-- that's what I use-found pistons (Datsun) to fit an old 4 cylinder Nash that I rebuilt a few years back that way. Unsafe--Your comment about welded rods I will cover in a coming post.Also you made a comment that 261 pistons cut the crown to deck height in half. The 261 pistons that I have are only 1/8" higher, pin to crown than the stock ones, and while any increase is a benefit, it takes more like 1/2" decrease deck to crown to get 7 1/2-1 I get this with 1/8 longer Ford rods, and 3/8 higher crowns on my homebrew pistons. Also I have, on a couple occasions made aluminum bushings for the wrist pin holes in pistons, honed after being pressed in. I always use aluminum plugs in the ends of wrist pins. and make the pins a light thumb push fit--makes installation a lot easier, and no chance of a snap ring going home to mother and letting the pin cut the cyl. wall. Lets hear those pushrods clatter! Herb
Herb, Sounds like you had alot to do with getting this started whetehe you realize it or not- your PM's to guys like me got things off the ground... so how's it feel to be the catalyst ? In all seriousness, I can't thank you enough for the time you've invested in me- looking forward to visiting in June! Take care, Bill PS- I'll try to get those lifters on tonight. they probably won't work for the earlier blocks, but might for the '28 OH, and don't forget everybody- Winfield made himself some roller lifters for his "2 up 2 Down" T engine back in the 20's... and would anyone like to try to make THAT crankshaft for a Chevrolet 4 ???
This is all too cool, when I started this thread I was expecting a few short and to the point replies about how the motor was garbage and how I should throw a sbc in it. This has become something far greater and I would like to thank you all and hope that you continue to pour your input into this thread, it is truly amazing what is happening here. I can't wait to get the funding for this project to really get it goin. We should definatly be able to build some bad machines out of this info. I read a post that said something about making a speed manual which would be really cool, maybe we can put together a website just for these motors in particular and all the vendors and machine shops that support them. I think that would be a really cool effort.
Hey guys, Here are a few pics (not the greatest quality) of the Saturn roller lifters. They are 21mm wide, 55mm long from roller to tip (53 from roller to top of body), and the rolling surface is 9mm wide:
Also, here is some info on Winfield's "2 up 2 down" engine. If I understand the story right, he wiped up the competition (including Chevrolet's Frontys) with little trouble- all the guys were trying to get a good look under the hood after the race. Note the roller lifters and crank... would be a real kick to see this done with a Chevrolet!
unsafe6, Here's a pic or two of the passenger car bellhousing for reference- the inspection hole was already there when I got the chassis ):
<meta http-equiv="CONTENT-TYPE" content="text/html; charset=utf-8"><title></title><meta name="GENERATOR" content="OpenOffice.org 3.1 (Win32)"><style type="text/css"> <!-- @page { margin: 0.79in } P { margin-bottom: 0.08in } --> </style> Thoughts on rods When I was a youngen and just starting to mess with engines, I asked someone in the repair business about welding connecting rods, and was told in no uncertain terms YOU CAN”T WELD RODS!!! I was also told around the same time that connecting rods broke, because at high RPM the inertia of the piston at TDC between power strokes would cause the rods to stretch and pull apart. Ten years later, in the early 60's I read a account in Sports Cars Illustrated about an English sports car company, who before WW2 had built a very special engine for an upcoming 12 hour race. The car and engine wasn't ready until the day before the race, and in practice, the engine broke a rod. There were no extras available, and no time to machine a new rod, so in an all night, do or die effort, the broken rod was welded back together, rebabbited and the engine re assembled. Seven AM the next day the cars were waved off and the race begun. Late in the afternoon our heroes car coasted to a stop with –guess what—a broken rod --- but the one that broke this time WASN'T the one they had welded. In the 70's I built a riding mower using a Gravley engine and transmission, and mowed 2 ½ acres of grass with it all summer. There is a back field on the property, an additional 2 acres that I only mowed occasionally with a farm tractor. Out of the blue I was offered more for the tractor than what it was worth so it got sold. In order to mow the field with the homemade job it needed more power- so I grafted a Harley cylinder on to the Gravley crankcase. To make the piston/rod connection I welded the bottom half of the Gravley rod to the top half of a Harley rod- the only way to get a rod the right length. I scarfed the joint, and welded it with E10016 rod- and ran the heck out of the rig for about ten more years, until I built something better with a diesel engine. Now two isolated instances certainly don't make an iron clad guarantee, but I have a motorcycle engineering book in which the well known author suggests fabricating a welded up rod from 4130 sheet stock, so welding a rod up from pieces isn't as far out idea as some might think. I would use the top and bottom of a Ford rod (better material) and a piece of 4130 tube in the middle. 4130 tube and sheet is available in small quantities from Dillsburg Aeroplane Works 717-432-4589 (no connection, just a customer for 25+ years) Tubular rods were used by Bugatti, Hispano-Susia, Miller—nearly every Offenhouser engine that ever raced had tube rods. It was the fact that H section rods could be forged to finished size as opposed to a lot of machine work on tubular rods that caused tubes to go out of favor. As for what size tube to use, I have a Hisso rod here that I just measured- it is 12” center to center (get to the significance of that in a minute),and it is .980” diameter at the top, and 1.060” just above the big end. There is a .790” hole through—so this means a .080” wall thickness at the top, and a .135 wall at the bottom. Now a less than one inch diameter tube with a wall thickness a little over a sixteenth doesn't sound like enough metal to keep a piston that probably weighs half again more than our Chevy's from pulling the rod apart does it? If rods fail in tension they should break at the smallest cross section- at the wrist pin hole, or slightly below it-right? Thinking about this a few years back, and remembering the broken rods that I have seen, the only failures that occurred at the top end was when one of those worthless GM rods with the wrist pin pinch bolts had the bolt fall out. All the rods that I could remember had broke somewhere in the middle of the beam—what was going on here? Finally a set of automobile engineering textbooks gave the answer. RODS DON'T FAIL IN TENSION! They fail, as a column, hinged at both ends, that buckles from a combination of the firing compression AND the inertia of the center of the rod section being whipped sideways by the crank moving the lower end sideways violently. The longer the column, the easier it is to buckle- so the C4 rod probably could use a even thinner wall than the Hisso- but no sense pushing our luck. As much of a sweeping transition as possible should be provided at both ends, especially the lower where it blends into the larger diameter crank section. Whatever replacement rods you make, or use, be aware that you cant use a rod of modern shape- where the big end sweeps into the midsection in a large curve – they are made that shape to help prevent the buckling- there isn't room at the bottom of the Chevy bore for a whole lot more rod cross section, Make a wood rod and try it first to make sure you have clearance here, and also between the big end and the cam lobes. Herb
The Jalopy Journal
