I'm working on a project and need some help.... Does anyone have accurate dimensional measurements for the block and cylinder head of a 1953 or newer (18bolt) chevy 235? Not just exterior dimensions, but also measurements for bore spacing, bolt holes, pushrod holes, coolant passages, port size and spacing, valve angles and spacing, ect... as indepth as possible. I have included examples of what I'm talking about. I know that it uses the standard chevy 4.40 inch bore spacing but the cylinders are not equally spaced due to main bearings, and I need exact measurements. Thanks
AFAIK no factory diagram is available. Some here may have data to contribute. My guess at the bore pitch: it's alternately 4-3/16”-4-3/8”-4-3/16”, &c. to avoid the 3 main bearing bulkheads between the cylinders.
Thanks for the post! Where did you get those measurements? Do you have access to a 235 block? If so can you take more mearurements? I have one but its still installed and running, and Im stuck at work 9 hrs from home for the next few months.
Good guess Panic...right on the money. I digitized a few blocks and heads to nail down numbers to make a torque plate, flowbench adapter plate etc. I don't have dimensions on a drawing but have CAM & G code data. What are you trying to do? It takes more than a caliper and micrometer to obtain what you have asked for.
I have a bet with a friend about hp potential for a 235. Obviously the stock engine is held back signifigantly by the design of the head and combustion chamber. However I feel there is potential for serious power hidden in the 235.
What I'm working on is a bed plate, and a crossflow 12 port head for the 235. It will probobly be similar in design to the wayne 12 port but use modern style rockers, wedge shaped combustion chamber, larger valves and aluminum as opposed to cast iron.
There are reports (unconfirmed) of people getting +300 hp from highly modified stock components and even more from the rare 12 port or chopped up sbc head applications, and forced induction. I believe with the right combination of components +550 NA hp is possible. ***No I'm not crazy, I realize thats a huge number for a stovebolt. Please limit your responses to constructive and informative posts rather than just yelling "your crazy" or "that will never happen".
--Planned component overview-- Crank - stock forged 235 (balanced rotating assembly) Rods - 261 job master (or custom) Camshaft - custom grind hydrolic or roller Block modified for 1 piece rear main seal and bed plate Dry sump oil pump Electric fuel pump Ignition TBD 12 port cross flow aluminum head (cc's and valve sizes TBD) Custom bed plate and oil pan Lightweight pistons with 1mm, 1mm, 2mm low tension rings
I know it will be a ton of work just to design the parts, but I have lots of free time and the desire to see it through. So please share whatever information you might have as any help I can get will be greatly appreciated.
Even if we confine this discussion to high-pressure 235s, this post still belongs in the Hi-Po Shop Forum. The atmosphere is different in there: "Thinking about a hotrod, street rod or other custom work? Stop in here. Shoot, we'll even talk about power brakes, power steering and CD players!"
"I believe with the right combination of components +550 NA hp is possible. ***No I'm not crazy, I realize thats a huge number for a stovebolt. Please limit your responses to constructive and informative posts rather than just yelling "your crazy" or "that will never happen". "
I'd be pleased to take bets on your being able to build this 235 engine and having it run for 100 hours before repairs are needed?
Last edited by tclederman; 12/07/20173:17 PM. Reason: added link to Hi-Po Shop Forum
Sorry I got busy at work for a couple days. What happend to that long post? No I'm not looking to be coddled or for positive encouragement from the masses. I am however looking for cold hard facts and measurements. The task I have laid out for myself is not easy but is most definately feasible. Designing a cylinderhead and bed plate for an exesting engine block is not some crazy impossible task. It just takes time and effort. CAD programs have made it much easier, but are not absolutely required. How do you think every internal combustion engine was designed prior to the computer age? Yes car companies utilize a team of engineers to design a single bolt, so to the average person it seems impossible. Don't be afraid of a challenge panic!
Yes I know others have done it in the past, and there are a very small number of 12 port heads out there for a small fortune. As far as I know, the wayne is for 15 bolt pre 1953 engines, its cast iron, uses the stock shaft style rockers (all exhaust no intake arms), and has an open chamber design. It was impressive for its time but not compared to modern cylinderheads. The sissel heads I believe are only for gen 3 gm inline 6's 194, 230, 250, 292. The only others I am aware of are frankenstein sbc heads or the toyota version that I believe requires modifing the block for a different bolt pattern.
Why has no one made a modern head for a straight six engine first introduced in 1929 and phased out for an updated and incompatible design which then ran until the 1990's? Does the introduction of the small block v8 in 1955 ring any bells?? The masses embraced the v8 and most (not all) forgot about the poor inliners. All aftermarket and gm support went to the v8, and v6.
My plan for the head. Aluminum Modern wedge combustion chamber with a cross flow design Stud mounted rockers (possibly roller) Probobly larger valves, the stock 1.50 E & 1.88 I are ok but not "huge for this displacement" Hollow tube pushrods for oiling the rockers
The measurements I asked for are the foundation of the design. Match the bolt holes, coolant holes, push rod holes, and cylinders and all the rest is designed around that.
I'll change the bet to 1 hour at full RPMs (is that a fairer bet)?
It would be a fantasy bet (funny money) and parimutuel in the fantasy payout.
One of our members is working on a "blown/supercharged" GMC 302 (I think that is what people might call it in the Hi-Po Shop?). He and his buddies will correctly (and, safely) measure HP. Maybe he will report back here?
Thank you for your posts. This is the engine shop forum and I have asked for technical information about an engine. Dimensional measurements, cylinder, bolt hole, and coolant passage spacing. I have asked my question in the appropriate place.
Curt B. Asked what I intend to do with the information, to which I stated honestly. Is honesty a cause for mockery and personal attack in this forum? What I choose to do with the information I may recieve here does not change anything nor does it mean that I dont belong in here. I have asked only for measurements and or illistrations and nothing else. Read the thread title and my original post carefully as they establish the topic for this thread. I get a feeling from your posts that you knoledge of internal combustion engines and their operation is very limited at best. If this is true or if you have nothing constructive to add please refrain from posting.
Well, well, well, attacking the members of the site who are just trying to engage you in a conversation about your project will get you lots of love around these parts. Tim is one of the most helpful members we have. Curt asked you a simple question which you should have answered unless your working on a top secret Government project. You asked a very technical question that only a trained machinist could/can answer. We have some here although they don't frequent the site often with the exception of one or two. After your tirade I doubt you will get any positive answers. Might I suggest you just move on to one of the more argumentative websites where you and your attitude will fit in just fine. BTW this thread will be forwarded to the Forum Moderator for his review.
Martin '62 Chevy C-10 Stepside Shortbed (Restomod in progress) '47 Chevy 3100 5 Window (long term project) ‘65 Chevy Biscayne (Emily) ‘39 Dodge Business Coupe (Clarence) “I fought the law and the law won" now I are a retired one! Support those brave men/women who stand the "Thin Blue Line"! Hug a cop! USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)
Forward this thread to me, please- - - - -I'll print it out and grind it up. It should make my garden grow very nicely next spring! LOL!
Putting that sort of head on an antique block with only four main bearings and connecting rods with the approximate rigidity of a strand of limp spaghetti and expecting any sort of success is kind of like transplanting the Incredible Hulk's torso onto a 70-year-old grandmother's legs. I wonder what the OP's been smoking? 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!
I’m not sure how you got “ mockery and personal attacks” out of my post but if you feel that way I apologize. If I am to GIVE away information that would allow someone to go into production of torque plates the same day ($800+ each) I don’t think asking what the intent of the data is used for is unreasonable. I do have all the information you asked for᠁PM me for a quote if you like but be forewarned price is relative to attitude and now is likely in cost prohibitive territory much like the rest of your plan. Good luck.
I saw a post on a Facebook group some guy claimed he had a 500ish hp from a 261 or 235 with just a few internal mods and was n/a. Best laugh I had in months. Sup Curt how you been?
I'm having Gaerte build me a blown 292 from the billet crank up. Should be somewhere in that neighborhood. I'll let you know next year after dyno. If that's your plan hold on to your hat. We are well over $30k at this point. May end up closer to $40k. 550hp on a 235? Why not go with the extra cubes? You know a lot more about this than me just letting you know what I'm spending my dogs inherintence on.
Sorry for any confusion. The post which mentions Curt B was intended for tclederman and only referenced curt B's earlier request for my intentions. Sorry curt B I apparently was not clear in whom I was directing it to. I will try to be more clear in the future to avoid confusion. Curt B and panic have been helpful and I appreciate your posts.
"We are not now that strength which in old days Moved earth and heaven; that which we are, we are"
1948 International Farmall Super A 1949 Chevrolet 3804 In the Legacy Gallery | In the Gallery Forum 1973 IH 1310 Dump 2001 International/AmTran RE3000 "Skoolie" 2014 Ford E-350 4x4 (Quigley)
Surely the early Wayne and Horning heads added considerable power to the Stovebolt engines back in the day. Trying to make a more modern version of one isn't that extraordinary. There might not be that much of a market for one, but it's fun to create and design. In today's times, it should be very easy to make more HP than the rest of the engine can withstand....
We cannot solve our problems today using the same thinking we used when we created them!
Why do practically all the hotrodders seem to think that increased power always comes at some warp speed RPM that a stovebolt cylinder head can't possibly accommodate ? Why not build for a reasonable increase in low end torque? Some engineer's wet dream of a cylinder head might be a good exercise in wishful thinking, but let's load up the beds of a couple of trucks to max gross weight and head up a few steep hills. "Horsepower is to brag about- - - -torque wins races" (and hauls a payload!)
"You really can make a silk purse of a sow's ear- - - - -but it makes the pig look funny, and it doesn't hear worth a flip! LOL! 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!
Curt, your info would make a lot more sense if you reposted it with code tags around it, which would keep the software from stripping out the spacing. example:
Code
column 1 column 2 Column 3
12 1.3578 7.4365
Code
here's how to do code tags
[code]
data here
[ /code] (Ieave out that space)
Or just use the tool shown in the picture.
Last edited by klhansen; 01/09/20257:35 PM.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
Those bolt hole coordinates are formatted so they can be copied and pasted directly into a CNC program without editing…As they are not in an attachment anyone can copy them without becoming a member or logging in. Open source for all.
Last edited by klhansen; 01/10/20255:56 PM. Reason: removed unnecessary quote
Thanks Curt, I didn't realize that. Not formatted for my easy reading. I don't have a CNC machine.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
I am working on building an adapter plate to fit an Atlas DOHC cylinder head to a 261 Chevy block. The original camshaft and timing gears will stay in place to drive the distributor and the oil pump, while the cams are driven by a toothed dry belt and adjustable sprockets from a rice burner engine. There's no point in reinventing the wheel when a suitable head that's already in production can be adapted to a different application. The Atlas engine is about 250 cubic inches, and the cylinder spacing isn't exact, but it's close. There are thousands of those heads available, and they're not terribly expensive. 24 valves, 12 ports, and three Weber DCOE 40 carburetors can be adapted, plus custom built equal length tubing headers- - - -what's not to like? 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!
A guy that was on the now defunct Atlas 4200 forum cast a triple Weber DCOE intake for the Atlas engines. It was a simple piece. I designed and cast a triple Weber DCOE intake for the Chevy 250/292 engines and a dual Weber DCOE intake for the Chevy II 153 engines a few years ago. I have already CMM'd an Atlas head and considered making one for that engine as well. Just didn't know if there was any real demand for it now that their forum is gone....
We cannot solve our problems today using the same thinking we used when we created them!
Anybody with some aluminum and a TIG welder can mock up a prototype manifold for dyno testing. Once a final design is perfected and tweaked on a dyno, anybody with a CNC printer can turn out production pieces by the thousands. Casting is so 19th. Century these days! 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!
