Building a replica Offenhauser style engine.
I am contemplating embarking on what I feel is a major project for me. I am still figuring if it is even feasable.
The project is building a replica of a very rare vintage midget race engine. It is an Offenhauser style 91 ci straight six built by a guy in Milwaukee by the name of Bill Willison. The original engine was in my father's midget he and his team built in the 50's. It has been under my father's basement stairs for 30 or 40 years. He recently unearthed it to loan to a museum exhibit. I figure now is the time to do something with it.
He has all the master patterns for new castings but only a handfull of blueprints, most of those being assembly prints. So needless to say a great amount of reverse engineering will be neccessary.
I am looking for information on engine machining and engine design. I am a Journeyman Tool and Die in the plastic extrusion field. So my experiance is a bit limited in the area of engine machining. Any direction to websites, forums, books, or maybe more importantly individuals familiar to vintage engine experiance wold be a great help.
I will try to get good pics of the engine in question to post as soon as I can. It is really a very beautiful motor.
Josh, I'd suggest you look (mainly in the Deckel forum) for some of the posts by Ross Cummings (AlfaGTA) that show him machining various vintage engines at his shop. He's had a number of Offy roadsters go through there and there was a stack of Miller parts too.
Oh man, I sure hope you do this project. My heart cries for those old noble engines. please post a the photos you can of the original and the replica you build.
Its a 6 and not a 4 cylinder??
Get Gordon White's book "Offenhauser" That would be a good place to start. Starts out with Miller,then on to Offenhauser,then Meyer and Drake,then Drake engineering. Lots of photos,and drawings from Leo Goosen as well.
Here is a neat little 110 Offy. Notice anything different about it??
Josh, check out these two websites:
The first shows a lot of the machining for replica Brough Superior engine parts, and the second the replication of an Excelsior board track racer. You ought to get some good information out of them (as well as a lot of entertainment).
Michael, Those board track racers are right up my alley. I have an interest in vintage motorcycles, bicycles and motorized bikes. Thanks, I'm sure I will be exploring those sites for a while. I bet my father has seen some of his work at the Miller reunion at the Milwaukee Mile this year. I wish I could have gone. Next year.
Andrew, I plan on getting that book soon. Maybe even order it monday. And yes it is a six. I guess it didn't have much low end grunt but more on top. They raced it only a few times due to rule changes allowing 120 ci and they couldn't bore or stroke it. So out it came.
Originally Posted by Andrew S. Quinn
Is the injection on the wrong side?
My dad and I both love Offy engines and performance parts. Please make sure you post lots of pictures, descriptions, any technical info that you can and pictures, pictures, pictures.
Years ago at the Cunningham museum in Palm Springs Calif, I saw Leo Goosen's drafting board. It was like going to church. Just think...EVERY American racing engine built from about 1930 until the four cam Ford Indy motor in 1963 was drawn on that old wooden board...Offy, Sparks-Thorne, Millers, Novi, and more.
I wonder where it is now? It even had the marks and scars from where his parrot perched on it for many years.
Please keep us updated on this worthwhile engine project.
I would suggest doing some research in to what happened to the original drawings. Those engines have always been valuable and the drawings no doubt exist. Having the patterns is a giant head start however you are going to have to find a foundry that is willing to use 60+ year old patterns. It's a great project and if you can come up with a set of drawings and a set of castings your suddenly well along
Another great book Miller Dynasty by Mark Dees.
A little pricey but a great read and lots of information.
Best wishes with a very interesting project!
If I understand correctly - you have the car but not the engine?
Probably the nicest of all the Miller/Offy books is The Miller Dynasty by Mark L. Dees, look for the 2nd edition. A bit expensive, but 550 + pages, a beautiful book, worth it. Sub-title: A Technical History of the Works of Harry A. Miller, His Associates, and His Sucessors. In other words, Offenhauser is covered as well, though the Offenhauser book mentioned above is possibly better for just Offy history.
I have also seen another book - Offy - America's Greatest Racing Engine by Ken Walton. I was a bit dissapointed with the photos, and didn't buy it because I am more interested in Miller engines than Offenhauser, however it is no doubt a 'must have' for anyone interested in the latter. The description I have says: it is probably the nearest thing you'll ever find to a technical manual on the engine and also includes a lot of background and photos.
All of these books are listed on the following website, and can also be found in the For Sale section of the website - along with cars and parts for sale. I see one advertisement for brand new Miller and Offenhauser blocks, (Offy blocks, $16,500).
Great to see any photos etc.
Yes it is. This engine is going in a Kurtis Roadster midget.
Originally Posted by TopDeadCenter
Seems I remember reading about a 91 CID Offy that was turbocharged in the Offenhauser book,only that was a 4 cylinder. Not the same motor then. I'd look it up,but my book collection is still in Maine,and I live in Indy these days.
Originally Posted by TopDeadCenter
Peter S : We have the engine and we may have a lead on one of cars EVM, my dads team, built. I don't know if this engine was in that particular car or not. The reason I would like to build a replica is I really don't want anything to happen to the original. It already has a cracked block, but that might be able to be repaired.
Ron Colonna has published abook and plans set on making a 1/4 scale 270 Offy from bar stock.
has a description of the book and a video of the engine running.
It's 4-cylinder, instead of 6 but may provide some inspiration or be of interest to fans of the other Offy engines.
What sort of equipment do you have available?
Being a journeyman T&D guy I would assume this project is not beyond your skills.
BTW, for the OFFY guys, was the head integrally cast into the block on all OFFy's? I remember seeing a shot of a special way they reached up the cylinders to grind the valve seats.
Offy Drawing Source
You might try contacting Stewart Van Dyne at Van Dyne Engineering in Huntington Beach, CA 714 847 4417. Stewart worked at Traco and then at Drake building Offy's in the turbo era, and he bought out John Drake a few years ago, including the remaining drawings, documents, tooling and the rights to make the parts. I've seen original drawings by Leo Goosen in his shop. His business includes rebuilding, restoring or recreating engines for vintage racers, so expect to pay for his assistance.
Let me know if you need some help with the patterns. 60 year old patterns are probably going to need some repairs, and possibly need to be revised/remounted fore more modern equipment. Are you thinking of just one new engine or a group of 5 or so to make sure to have some spares if you are going to race this on a regular basis.
another Offy lover
I bought another book on Ebay about the Offy with plenty of pictures and info. It was $100 and well worth it.I will check the title when I get back to the ranch, and post it next time I'm in town. I have been tooling up to build Offy parts in 1/4 scale,starting with the 270. I am also a fan of the 1966 168" Roots-blown engine. I have several bar and chuck automatics,including a Swiss type( which will be blanking out the camshafts).The cranks will be turned on the Pratt & Whitney Starn Turn, retrofitted to EMC2. The cranks and cams will be finished on the Van Norman 101 piston grinder.The plan is to start small and work up to the larger engines.My background is in vintage mc parts, particularly Indian and HD. Eric in AZ