4 Banger question,..Chevy ohv heads on Ford B blocks,..Good/bad??

Wow, quite a thread. I have a chevy OHV conversion on my car and I guess we now have a baseline on the chevy setup. For the money, I am very happy and am very unafraid of the local flathead guys. I have a few races to run against some modded flathead engines and then I will get back to you. I will try to run the donut derelicts crowd as they all drive modded expensive flatheads. I do run a full weight coupe so I will try my best to run apples to apples comparisons. Neal Jern checks this board about never.

 

Here is a picture of an olds 455 head on a banger

 

Stovebolt,

Any more pics or info on this conversion?!

 

No unfortunatley I don't know who did the conversion. I had the picture stored on my hotmail account for something like 8 years, and rediscovered this thread, so posted it. sorry.

 

There is a gentleman named George Miller from NC on the Fordbarn Model A forum that has built one of those conversions. I feel certain he would help you if you want to contact him (do a search for his name) ...but based on what he has told me, this would not be for the 'faint of heart' machinist. It makes great power in his Roadster as he has been the "King of the Hill" several times at the F.A.S.T. Fiddlers & Fiddleheads hillclimb.

 

That'd be him, as I have it saved as Miller-olds head. Do you have any later pictures of this setup?

 

Brent,

Thanks for the info- not going to build one, just thought it was a creative modification!

 

Several points to note here.
1. The cobbled together Windsor or Cleveland head on a 'B' or 'A' block would require a differently configured camshaft to operate the valves. Late Fords are E-I-E-I-E-I-E-I. The 'A' or 'B' is E-I-I-E-E-I-I-E - the very reason Bill Stipe modified a pair of SBC heads to bolt on to the Ford Banger!
2. The 303 - 324 - 371 - 394 Olds heads don't even come close to fitting the Banger block. They are as much work as doing the Stipe modification.
3. The 455 Miller-Olds adaption MUST be running a custom designed billet camshaft. Because the Olds valve sequence is I-E-I-E-E-I-E-I. Otherwise Miller did a lot of cast iron welding individual combustion chambers together to get the correct Banger valve sequence.

 

Have there been any recent F head conversions for the A & B blocks, In the 1950s Elva Willment & LRG did them for 72 cubic inch baby B block in the UK 90 to 110 hp have been quoted running twin SUs or four inch & a eighth Amals

 

Andy Jenkins from Broken Hill made one. Someone in the 4 ever four club in LA has the patterns of it now.

 

Just look at the size of the ports and you can answer your own question. If I remember correctly when you look at the size of the ports on the Chevy head you won't have to think very long.

Charlie Stephens

 

It's time to resurrect this thread.

I have read this thread several times in the last few weeks and think it is time to go over some of the facts that I have found regarding the 1928 Chevrolet head.

The reason that I found this thread in the first place is that I had a chance to purchase 4 of these 28 Chevy heads very reasonably. When I asked the seller what they were he said that they were 28 chevy heads. Somewhere in the far reaches of my memory I recalled that they were used on Model T or Model A Fords


As it turns out they have been sucessfully used on both. So being a shrewd shopper I bought all 4 of them thinking that I could sell or swap them for something that I need.

When I got home and examined them I found that 3 of them were in very good condition and the other was probibly salvageable. None of them had rocker arms or rocker shafts but 2 of them had valves.

Anyway I did a search on this site and found this thread and another which gave a name and the name of the adapter kit. I then looked it up on the net and found a number for Neal Jern. I called him and asked him some questions and requested purchase information.

Neal is a great guy and I found that he is a straight shooter. He has been very helpful. His kit is reasonable and he also has heads available at a reasonable price.

Here is what I found and figured out. The 28 chevy head has 2 inlets similar to the model A's. While it only has 2 exhaust ports they are on the other side of the block making it a cross flow head with the intake on the drivers side and the exhaust on the passenger side.

The valves are all 1 5/8" but the intake can be enlarged to over 1 3/4".
I am going to use ford small block stainless steel valves 1.60"exhaust and 1.840" intakes. The inside of the ports are cavernous but do not lend themselves to a smooth flow however at the rpm my engine is going to turn it won't make very much difference.

The stock valve guide castings are large and will inhibit flow so I will have them removed and have the valve guides exposed and tapered to relieve this condition. I will also do some modification to the ports cleaning them up and enlarging them a little.

The big plus is that the rocker arms have a 1.5 lift advantage over the model A. This increased lift and the tremendous valve increase should make for a good combination. Neal provides adapters of varing thickness giving 6.1. 6.5 and 7.1 compression. Neal said that he recommends that the 7.1 heads work best with pressure oil and Insert bearings.

The Spark plug pockets look like they will present a problem because they keep the spark plug tip too deep in the pocket. I think that I will machine the outside of the pocket and tap the spark plug hole 1/2" deeper and install the bottom of a 2 piece spark plug that has been taped for a smaller long reach plug. That will put the spark in a lot better position.

While these heads probibly won't perform like $3,500 or $4,000 heads I think they will provide a lot of bang for the buck on a Model T, A or B block.

I think that there is a lot of Ford on Ford sentiment in the hot rod hobby and I am one of those who generally agree but Old is Old and I think an old chevy head should just be a acceptable as a modern cast after market head and even though it might not perform quite as well it still offers a big improvement in performance and as stated before it dosn't cost an arm and a leg.

I will be installing the chevy head on my 1930 woodie mail truck that has a H&H touring engine in it. I purchased a 2 barrel stromberg 97 manifold for this head. I will probably will use the Demon 98 carb I recently purchased on it although I have a couple of 97s iI might install if I can fine one of them.

When I get my conversion completed I will let you know how it worked out.

Dick

 

sounds good!
let us know

 

I run a chev head on my tee roadster no dyno figs but believe me it goes like hell the challenge is in doing it and keeping that old time feel it was a neat project and gives me a lot of satisfaction I recon the next challenge will be to make my own patterns for a head if i follow modern practices say based on a twin cam toyota it should be ok after all thats what the old timers did in their back yards back in the day

 

Allow me to play Devil's Advocate with you if I may to stimulate more thoughts on this......

I own several OHV heads including a '28 Chev. conversion for the 'T' and an 'A'. While I have never run the 'T' conversion, I have used the 'A' conversion. Allow me to offer my thoughts... (Naturally your thoughts may be different and that's OK!)


Not all rockers that fit that head are 1½ ratio. The '27 rockers were 1¼ ratio.

IMO, having an intake valve that large is a hinderance for two reasons; A) There is not a "designed" combustion chamber (i.e.: Ricardo) to keep the drawn in fuel in suspension. B) Exhaust efficiency due to the 2 port design becomes the limiting factor.


While I think the "WOW" factor is definitely there, the performance factor has fallen by the wayside. While I realize you have obtained your heads at a low dollar amount, the investment in time may very well offset the costs. Again, the value of "different" under the hood sometimes is worth something, however for me personally, I think this is a classic "form over function" design where performance takes the backseat to having a 'WOW' factor.

Now here is my perspective with regard to me using one. The R&D, ...and technology that has surfaced with the Model A/B engine performance in the last decade has grown tremendously, --especially with the flathead. Bill Stipe (a speed equip. mfg.) is a very good friend of mine, and I had the privilege to see some items he was R&Ding at his shop last week. He is already making over 100 horsepower with a Model B flathead, ...and he has designed a combustion chamber for a head, along with the camshaft & valvetrain that will easily make over 125 horses, --and maybe even 150 horses and yet still has an awesome torque band that a Model A/B is known for. THAT is the thing I believe you will be giving up with the Chev. conversion, and especially if you enlarge the valve & port size. When the fuel mixture slows down (due to velocity drop) the fuel falls out of suspension and de-honogenizes. I truly believe this is why 70-80 horsepower is about all anyone has been able to coax out of a Chev. head conversion.

Now don't get me wrong, 75 horsepower is a great hop-up over stock, however a flathead with a good aftermarket 7:1 head, 1.750 valves, a Stipe camshaft, good carburetion & header, and electronic ignition will also make 75 horsepower for less than $2k for those listed parts. For most people, even being a great scrounger will find they will have more money in finding all the parts to do the Chev. head conversion. Do you agree?

.

 

Brent,

Thanks for the input. It always helps to get other prospectives and Time will tell, I will be satisfied with 75 to 80hp if that is all I will get.

I will put the S10 T5 5 speed overdrive transmission kit I already Have behind it and will be able to pull the hills and cruise down the freeway at what ever speed the chassis will safely handle.

It will look good under the hood and it is different than so many others that I see at events.

If I want more Bang for the Buck I will put in one of my Mercruiser 3.7 engines that produce 230hp and cost less than 2,000.00 to build. I will eventually do that anyway and put this engine in my 1929 Tudor.

Mercury Marine engineers found that the 3.7 Mercruiser created more torque with the small valve 460 Ford cast iron head than with the big valve 429 head. That was what they needed in the inboard boat application.

The Mercruiser engine is 224 ci engine and came with 1.655 exhaust valves and 2.078 intake valves. The valves that I will use in the Chevy head will be stainless steel chrome stemed 1.600" and 1.840".

I will find out if I have a fuel problem with a modern 2 barrel carburator after I install the conversion. If so I have more of the heads that I can put smaller valves in.

The main advantage is that the valves will open 50% more than the Model A valves and even if I left them the stock size they are slightly larger than than Model a's at 1 5/8".

I will agree that the Ford engineers better understood port flow than the Chevrolet engineers but the valve size and lift should more than make up for the flow advantage. And getting the combustion chamber over the pistons has to be advantageous over the flat head design.

I understand about throwing big money after the little money. It seems that I specialize in that.

I also like a challenge so wish me luck.

Dick

 

I guess I should have mentioned that but I believe that my logic really only applies to the 'A/B' engines. While Bill is making some pretty cool prototype stuff for Model A's & T's, ...there has not been nearly the time nor development spent on the T breathing. Since that is the case, the Chev. head conversion may be a better bang for the buck.

Here is a billet crankshaft for a 'T' that is stroked & counterweighted. Also, adjustable timing gear anyone??



.

 

Brent,

You have been at this a lot longer than I have. This is the first Model A engine modification that I have tried.

I have been trying to understand part of what you posted a couple of post back. Could you explane it for me?

"He is already making over 100 horsepower with a Model B flathead, ...and he has designed a combustion chamber for a head, along with the camshaft & valvetrain that will easily make over 125 horses, --and maybe even 150 horses and yet still has an awesome torque band that a Model A/B is known for. THAT is the thing I believe you will be giving up with the Chev. conversion, and especially if you enlarge the valve & port size. When the fuel mixture slows down (due to velocity drop) the fuel falls out of suspension and de-honogenizes. I truly believe this is why 70-80 horsepower is about all anyone has been able to coax out of a Chev. head conversion. "

I have always read where people were trying to enlarge the valve and port size to get more HP.

I also don't understand how the velocity drop thing works. Why doesn't it effect other engines with big valves and ports the same way?

Being new at this I appreciate all of the help I can get to understand the principles involved.

Dick

 

Dick, at risk of over-simplification, bigger ain't always better. The flathead A/B engine already has too big of an exhaust valve. That is why it does better when a larger intake valve has been installed. If a 1.750 intake were used and a smaller exhaust (i.e: 1.250+/-) were used, then it would see a larger increase in power because the smaller port would pick up some scavenging.

On the intake port side, a couple of things needs to happen and much of this is WAY more detailed than I care to type in this one spot but let me hit the high points. Starting out, siamesed intake ports are a bad thing when it comes to reversion and velocity. A divided port is a good thing. When you have a "common port", the velocity needs to stay high to aid in keeping the heavier fuel vapors atomized with the air. If the mixed fuel is tumbling & swirling along the path, then it stays in suspension however if it slows down, it tends to cling to the walls or fall out of suspension. When this puddling happens, all the air does when it passes over the fuel is take some vapors with it. Now in the case of a OHV like the Chevy head, this happens even more frequently plus that unatomized fuel just falls into the cylinder which really has no combustion chamber to swirl the fuel. Now that fuel is laying on top of the piston and it is slow to burn and does not make any power.

With regard to the effects of the Model A/B vs. other engines, I think to a certain extent it does. I am of the opinion that you need to compare apples-to-apples though. Do not mix data from an L head with an OHV head. If you want to look at L-head R&D data, you need to look at all the research that has been done with Jr Dragster and kart engines. Next in line with that is the money that Kohler has spend on garden tractor puller engines trying to extract horsepower from a flathead. While some of what the old timers found worked remarkably well during the day on racing A/B engines, there is quite a bit that has been proven incorrect. Since this is a 'traditional' site with a favor towards traditional methods & practices, I won't go into all of the new technology however several engine builders are now able to extract well over 100 horses now out of a flathead. Matter of fact, just to show you how technology was advancing, the Hudson Twin-H engine was making 145 horses out of a 308ci flathead, --and their 7X racing engine was making around 180 hp. If you factor in the hp to cubic inch ratio, that was .47 and .59 respectively with 1950s technology. Up until the last decade or so has the flathead banger been able to jump above 80 horses, --and now with some combustion chamber revamping, air flow and camshaft changes, there are guys making a conservative 100 horses with a flathead which if you take a Model A/B cid and multiply it by the the ratio of .50 (middle of the road of what hp the Hudson made), you will see that we should have been making over 100 horsepower a long time ago. This is where peple like Bill Stipe have been able to use their technology gained from a dyno and then apply it to the camshafts or the heads they make. While I am kinda deviating from the original question, I think it bears repeating that the Chev OHV does not have an engineered combustion chamber, and thus it will never make the power. I agree that it will flow air more efficiently than a L-head can but I liken that to two pro football teams and one of them has lineman from the local high school team. Having the great quarterback just cannot play effeciently with the unmatched linemen.

One other thing I want to comment on, I can remember in the late 70's/early 80's when several engine builders of who I respected made comments to the effect of SBC heads had just about reached maximum potential and the likelihood of them ever making even another 10 horses out of them would be very slim. THEN with the age of computers and simulation, think of all the advancements that have been made making greater hp, and much more torque at lower RPMs. It has made the revered 2.02 dbl hump heads obsolete in racing and it was all in a combustion chamber design and how the air flow was delivered. I trust I have helped you somewhat. BTW, you have a very respected banger-builder in your town of whom I have much respect for, and even raced one time with. Befriend him if you already haven't!!

.

 

The combustion chamber is large on a 1928 Chevrolet!! Say what!! Have you ever look at a 1928 Chevrolet head. Mine and the other 5 that I have are all FLAT. There is no combustion chamber in the head at all. Small block chevy V-8 valves and springs will fit in them too. See my 28 Chevy dragster by my name. PS...never got beat in NHRA drag racing X/D by any Ford powered dragster. Even the ones with overhead conversions!

"Wan't anybody ther except me and Little Skeet"

 

Little Skeet,

We have a thread about working on early Chevrolet 4's- would you be willing to share some of your info there? Here's the thread:

http://www.jalopyjournal.com/forum/search.php?searchid=9670549

Thanks, Bill

 

My posting was on the Chev/Ford conversion plate not a stock Chev head.

 

I am going to do it too, but am going to put a 3-port Olds head on my Model A.

 

The 28 Chev head does not do that much for the A or B engine. They have small valves poor ports and flat coumbustion chamber.
I put a 455 olds head on one of mine and won king of the hill 4 times.

A good flat head engine with a good flat head, like a Brumfield 7-1 the right intake good exhaust, right cam, 283 chev pistons 1-3/4 intake valves will out run the chev head.

 

I put one on one time. I made my own plate with a combustion chamber. Put in bigger valves. But the head is not up todays standards. It worked ok but my strong flathead was just as strong, maybe stronger.

 

The 455 olds does not have the same bore spacing. You have to add a spacer in between 2,3. As far as I know I'm the only one that has put a 455 on the A engine. You have to move all but 2 head bolt holes, all the push rod holes.

 

That picture is of my engine. It runs very strong. If you would like to see pictures of it in the car click on my name. You can also see pictures of the head I made from scratch. I'm not trying to steal this thread but every one is asking.

 

I am putting an Olds 3-port on my model A so that I can experience what some of the earliest hot-rodders did. Plus I am a glutton for punishment. If I wanted the cheapest HP I would put in a SBC.

 

I play with banger motors I have put a Chev head on a tee motor I am very happy with it .If i just wanted horsepower I would have just slapped in a small block Chev[yuck]
But as a tinkering old bastard I got great satisfaction out of doing this and learnt one hell of a lot in the process. In my view the answer is simple if you just want horse power bang in a belly button motor If you want just a fast A or B motor have some one build you one with a modern overhead conversion If your buzz is making an old motor go better in a traditional way with the satisfaction of saying I did it with minimal equipment go for it its FUN and can be done has the wow factor and boy you will learn about your car when you have finished you should be able to do any repairs on the roadside just as they had to in the past go on I challange you.

 

George,

Thanks for resurrecting the thread! Do you have any more info/pics of your conversion? I'm in th process of building a '28 Chevrolet engine with an Olds 3 port, but the 455 looks intriguing