Here ya go, Lots of bits to find yet but it's coming along. Fixed threads, pulled valves. I have all the stuff to fix the threads if your local and need it. Here's what the adapter plate looks like. I hope my homework was correct on enough clearance. Begin intake fab. Complete intake, Pain in the ass getting flanges correct so floats don't leak. I made the headers out of some BBC motor home headers. I need to remember to make baffle mounts before they go to chrome. I am waiting on a Miller side cover to wrap up the valves and now useless inatke and exhaust ports. This is the last pic for now. I can run this thing without a valve cover, on quick jaunts, since there is no pressure oiling up top ( for now). It'll be interesting.
Ermmm... What is the CR on that? About 2:1? Or have I missed something very important? Not pissing on your cornflakes just interested. P.
So. If I am getting this right the pistons would have had the chamber? Does that mean that to use this OHV conversion that flat top pistons are used the adapter provides the combustion chamber and the new head is flat? P.
Sorry for the nube comment here on this stuff, but its a chevy head on a flathead 4cyl ford right? Just making sure, because I thought chevy never made a flathead motor in any form.
It's 6.1 comp, It's a 28 chevy head on a model a ford engine. I have spoken with some folks running the same setup and it works. If you compare the combustion chamber in a stock head compared to the adapter plate it's much smaller. There is NO combustion chamber in the chevy chamber to spoil the mix. 100 hp should be attainable. "That's the going hp rate in a shop that specializes in this conversion." I'll put her to the test and share. When it blows up this bottom end I will invest in a better one but it's gotta earn it by running hard. I purchased the kit from Neal jern custom Machine. It cost around $1600 with every bell and whistle except intake and exhaust. I got out of buying adjustable lifters when I scored some HAL lifter adapters. Man they are cool.
The stock Chevy pistons were flat, and didn't come up anywhere near the head at TDC. This resulted in a combustion chamber shaped like a can of tuna fish--not very efficient.
When you bought the kit did it include the head or did you have to source that yourself? What year range Chevy heads will work? It may be time to start looking in the woods for these parts! Thanks, Reece
Tuna Fish Head, that's funny. I included a pic to help make sense for some. The head is 28, I don't know what else would work. The head came with the kit and was cheap compared to the rest of the parts. I have no clue how many spares he has left. He also has an olds 3 port head adapter which is supposedly faster, yet the olds shit is more rare.
Most of the Chevy 4 heads had one rectangular exhaust port, so the two port '28 head is a step up from that. Those combustion chambers formed by the adapter look a lot like '54 Ford OHV heads.
Very impressive, neat workmanship, Nice to see something different. Like those wires. I'm going to use the stock winged cap with similar wires on my next engine. Finish it up and bring it to the hillclimb.
On the Hal pieces, My camera is dead but I got em for $20! They are an interference fit over the stock lifters and the top is a femake socket that the pushrod rides in. Valve spring pressure holds it all together. Seems precarious but That Hal fellow was pretty sharp so I got faith.
so the head is not milled down at all? how thick is the adapter plate? almost looks like a vortec head in away, will you be doing any radiusing of the plate? questions, questions.
Cragar and others use the same adapter on the lifters but most were not interference fit and sometimes when a pushrod was pulled they would follow and drop into the valve chamber necessitating removal of valve chamber cover. Currently the single lock lifter is used with a 3/8" 24 allen cap screw radiused with a ball endmill. Some even use jam nuts and have an adjustment there also. I just locktite mine in.
Interference fit means they just fit snugly over the stock lifters. I would like some like yours Bill someday. The plate can be milled for more compression but there are bolts going both ways so there is a limit to it. I wish I sprung for the cast iron adapter plate as I think it would seal better and look more correct. That is the million dollar question, Will it seal on that worn out old deck surface? Will I have to remove the cylinder head to retorque the adapter plate after a few heat /cooling cycles? That's what'll keep me from the hill climb.
The pushrods are smith brothers (included). You oil the rockers with an oil can now and then. A spray deal would be easy enough down the road but that is the least of my worries for now.
Thanks for posting this. Keep us updated. I've got just about all the parts that I need to do this conversion on a T engine with a 28 head, except that I haven't bought the plate yet. I sure would like to see some before and after dyno numbers before I shell out the bucks. I also question whether I shouldn't just build the Chevy engine instead of doing a conversion to the T engine. I have all the parts to do that, except for any speed parts that I would add to it. Seems that the only negatives to getting the same horsepower are that the Chevy has a few less cubic inches and available cams may not be as good as Stipe's T cam. Same goes for the A conversion. Thoughts?
According to Jern, 100 hp on the T engine is possible with a 280 cam=. 420" lift with the chevy 1.5 rocker ratio. I don't know anything about chevy fours. This gentleman in Mass is building one too. www.Gen3AntiqueAuto.com. 774 213 5440. He has some nice pics of it under "Poor man'S RAJO" He said he knows a dude in Mass with one on his T and it overpowers the car to the point of being scary. Is that what you are looking for?
That may be possible, but not with just the 28 Chevy head, a cam, and a couple of Winfields. It would have to quite radical, I would think, to make anywhere near that amount of power. For comparison, George Stupar's B engine with a Crager conversion makes 86 horsepower. It has headers, a Harman Speed cam, 9:1 compression, and dual Winfields. I doubt seriously that a 28 Chevy head flows even close to what a Crager flows. I'd be happy if I did the conversion on a T and it made 50 hp.
Yeah who knows, I am just sharing what I read in SOSS. That cragar motor is dissapointing though to say the least. Guys are making 80 horse with flatheads. The proof is in the pudding. You can't race a dyno. If I want to go fast I'll jump in my "other car".
what are you using for head gaskets? i guy i know did the conversion himself and had problems sealing he said
True. And the same for me, that my "other car" is the one for going fast. But, I just don't want to spend twice as much on doing the conversion, if I can get the same horsepower out of just doing the whole Chevy 4 engine. And, even if I use the T engine, I'm still not sure that I couldn't make the same horsepower using the aluminum flathead. You can't race a dyno, but you can sure get some good scientific information for some basic comparison on which you can make a reasoned decision. I'm not implying that you've made the wrong choice. I just haven't made my own choice yet. I'm looking forward to seeing your results.
I am not trying to be a smartass in any way. I want to build a traditional four cylinder car. For me that means an A or B block based hodge podge. I applaud your research and quest for big power. If you want a hot setup this one is ok, but there are much faster ones out there. I could afford this setup so here I am. The head gaskets are copper/ something custom pieces. It should be running in a couple weeks so I will have more to share then.
Man! This is NEAT! But I gott tell you... your safety wireing is all wrong... you have it tied so that one header bolt will actually LOOSEN... When you put the wire on, then take it to the next bolt... remember that when you are pulling it, it needs to tighten the bolt, not loosen it. Sometimes you need to pull clear around the other side... Sam.
Fine looking motor, Sawracer. I'll be following this one closely. BTW, I'd be seriously disappointed with a Cragar-headed motor that only made 80bhp.
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