Chris Etzel "big" 255-270ci Offy: any repops, any info, anybody have one?

[Ace-Garageguy]

I'm beginning research for a series of vintage sprint car models and I'm looking for a resin big Offenhauser engine done by Chris Etzel some years back. My research and measuring show this engine to be closer to correct scale than the undersized mill in the AMT Watson Indy roadster. Any info or leads??

[jas1957]

Replicas & Miniatures of Maryland repoped that enigine a couple years ago. Not sure if it is still available or not.

[Bernard Kron]

Replicas & Miniatures of Maryland repoped that enigine a couple years ago. Not sure if it is still available or not.

Yeah, I built one. Everything we would expect from RepMin. Superb detail, faultless fit, immaculate castings. It was limited production but I suspect it is still available if you ask.

Here's a link to my Under Glass post: http://www.modelcarsmag.com/forums/index.php?showtopic=22278

[Len Woodruff]

I just got one last week. Unfortunately it is way too big for the Watson Roadster.

[Art Anderson]

Yeah, I built one. Everything we would expect from RepMin. Superb detail, faultless fit, immaculate castings. It was limited production but I suspect it is still available if you ask.

Here's a link to my Under Glass post: http://www.modelcarsmag.com/forums/index.php?showtopic=22278

If you mean the AMT Watson Roadster, yes Chris's Offy is too tall. AMT cut a lot of corners, made an awful lot of compromises in that kit, frankly. It's Offy engine has a block height too short even for the 220cid Offy engine, it's almost as short as the Midget Offy that Revell does. It is, however, an extremely accurate 1/25 scale replica of the post-WWII Meyer-Drake 270cid Offenhauser racing engine, which was taller than all but the first few 255's which debuted at Indianapolis in 1956. He made that engine to be a part of his fantastic kit of Jimmy Bryan's Dean Van Lines Dirt Track Champ car, which was a Kuzma chassis, built in 1954, and finished second at Indy in 1955.

Art

[Psychographic]

Bill, I'm not going to pretend I know anything about Offy's other than they are very cool looking engines.

The engine provided in the old Monogram Midget kit is pretty big. Although it lacks detail and accuracy, it can be modified to look pretty good. Here's one I did for a 48 Ford Woody.

It starts about 1/2 way down the page.

http://www.modelcarsmag.com/forums/index.php?showtopic=64504&page=3

[southpier]

that came out great

[Ace-Garageguy]

Thanks for all the info, guys. I have 3-view drawings for the more common Offy engines, but honestly hadn't bothered checking the scale dimensions of the 1/18 (approx) engine in the old Monogram midget kit to see if it could work in 1/24-1/25. I'll give it a look though.

I just got one last week. Unfortunately it is way too big for the Watson Roadster.

Thank you sir. I'll shoot him an order shortly.

[Ace-Garageguy]

The engine provided in the old Monogram Midget kit is pretty big. Although it lacks detail and accuracy, it can be modified to look pretty good. Here's one I did for a 48 Ford Woody.

http://www.modelcarsmag.com/forums/index.php?showtopic=64504&page=3

Man, that looks great. I'll check the dimensions on that kit for sure!!

[Art Anderson]

Thanks for all the info, guys. I have 3-view drawings for the more common Offy engines, but honestly hadn't bothered checking the scale dimensions of the 1/18 (approx) engine in the old Monogram midget kit to see if it could work in 1/24-1/25. I'll give it a look though.

Thank you sir. I'll shoot him an order shortly.

I was part of a small, very dedicated group of 3-5 local builders here in Lafayette IN who specialized in building (almost exclusively!) models of Indy cars from the late 1960's into the early 1980's, and we encountered the problems with the AMT 255 Offy as noted above (not tall enough).

A little bit of history on the real engine, if I may: About this time in 1955, The American Automobile Association (AAA) announced that it was disbanding its Contest Board (the sanctioning body for the Indianapolis 500 Mile Race and the associated "Championship Trail", principal governing body for sprint cars and midgets) due to the visibly tragic crash at Indy which killed driver Bill Vukovich Sr., and the horrific crash at LeMans that June which claimed the lives of not only a driver, but 80+ spectators along with over 100 other spectators seriously injured--all of which caused a tremendous public and political backlash against all forms of motorsports (Auto racing was banned by law in several European and Scandinavian countries--and bills were introduced into both houses of the US Congress to ban racing in the US). Out of this came the United States Auto Club (USAC), which immediately introduced a smaller engine formula for the 1956 season: 255cid (4.2 liter) as opposed to the long-standing (since 1937) 4.5 liter or 274cid engine displacement limit.

Meyer& Drake, DBA Offenhauser Engineering designed a new 255cid Offy simply by decreasing the cylinder bore and a slight shortening of the stroke, which took the "long stroke" 274 and made it an even more "undersquare" (bore smaller than the stroke) 255. However, John Zink Racing's chief mechanic, AJ Watson had a different idea: Mill off the bottom end of a 274 block (remember, NO racing Offenhauser engine ever had a detachable cylinder head--the cylinders were "blind bored", with the combustion chamber as part of the block itself). This made for a short stroke, or "oversquare" engine, which could wind up to rpms unheard of with the old 274's, and gave more torque and HP in the bargain. Now, how we here in Lafayette figured out how to make the AMT Offy from the Parnelli Jones Watson "Willard Battery Special" kit:

While we had to live with the molded on water jacket cover plates on that model Offy engine (the finned, removable plates on the sides of any Offy engine block), we could still stretch that inaccurately low AMT block with a piece of .060" thick styrene (Squadron Shop started marketing small sheets of styrene about 1970 or thereabouts, and .060" was one they made available). on top of the block, as AMT tooled that engine with the top of the block & cam towers as a separate part (almost like a cylinder head IF Offies had ever had detachable heads!), and then after shaping that to the length and width of the kit engine block, simply center the top end part to the heightened block. Visually, it worked very well, gave at least the visual appearance of the real thing (with two individuals here each having 255 Offenhauser engines--long time racing mechanic Bob Higman, and racing photographer/memorabilia collector Ed Hitze Sr and of course, a race car museum and restoration shops only 65 miles SE--Indianapolis Motor Speedway of Lafayette, having several 255's in race cars, on display and on stands in the restoration garages we did have a lot of references at hand!)

Bear in mind though: Every different displacement Offenhauser has it's own set of external dimensions. Given that they were all built with block and crankcase as separate units, the longer the stroke, the taller the block and the wider (fatter) the crankcase). Even if the old Monogram PC-1 Midget (which I think is 1/20 scale BTW) engine would fit in a 1/25 scale model for length, it's way too tall proportionately. This is because while Offy engines for larger race cars had 5 main bearings, the 91-, 110, and 120-cubic inch Midget Offies had just three mains, which made for a crankcase at least 4 to 5 inches shorter, and a shorter block (front to back) in the bargain. Also, the stroke of all those sizes of midget Offies is much shorter than even the 220cid sprint car Offy, the block is shorter, but the cam towers are still nearly as tall as on the larger engines.

If I didn't have a couple of Chris's excellent resin engines still in my stash, I'd probably just go back to the way we here figured out back over 40 years ago, certainly for a classic late-60's through 1966 255cid normally aspirated Offenhauser 4.

Art

[Len Woodruff]

I was part of a small, very dedicated group of 3-5 local builders here in Lafayette IN who specialized in building (almost exclusively!) models of Indy cars from the late 1960's into the early 1980's, and we encountered the problems with the AMT 255 Offy as noted above (not tall enough).

A little bit of history on the real engine, if I may: About this time in 1955, The American Automobile Association (AAA) announced that it was disbanding its Contest Board (the sanctioning body for the Indianapolis 500 Mile Race and the associated "Championship Trail", principal governing body for sprint cars and midgets) due to the visibly tragic crash at Indy which killed driver Bill Vukovich Sr., and the horrific crash at LeMans that June which claimed the lives of not only a driver, but 80+ spectators along with over 100 other spectators seriously injured--all of which caused a tremendous public and political backlash against all forms of motorsports (Auto racing was banned by law in several European and Scandinavian countries--and bills were introduced into both houses of the US Congress to ban racing in the US). Out of this came the United States Auto Club (USAC), which immediately introduced a smaller engine formula for the 1956 season: 255cid (4.2 liter) as opposed to the long-standing (since 1937) 4.5 liter or 274cid engine displacement limit.

Meyer& Drake, DBA Offenhauser Engineering designed a new 255cid Offy simply by decreasing the cylinder bore and a slight shortening of the stroke, which took the "long stroke" 274 and made it an even more "undersquare" (bore smaller than the stroke) 255. However, John Zink Racing's chief mechanic, AJ Watson had a different idea: Mill off the bottom end of a 274 block (remember, NO racing Offenhauser engine ever had a detachable cylinder head--the cylinders were "blind bored", with the combustion chamber as part of the block itself). This made for a short stroke, or "oversquare" engine, which could wind up to rpms unheard of with the old 274's, and gave more torque and HP in the bargain. Now, how we here in Lafayette figured out how to make the AMT Offy from the Parnelli Jones Watson "Willard Battery Special" kit:

While we had to live with the molded on water jacket cover plates on that model Offy engine (the finned, removable plates on the sides of any Offy engine block), we could still stretch that inaccurately low AMT block with a piece of .060" thick styrene (Squadron Shop started marketing small sheets of styrene about 1970 or thereabouts, and .060" was one they made available). on top of the block, as AMT tooled that engine with the top of the block & cam towers as a separate part (almost like a cylinder head IF Offies had ever had detachable heads!), and then after shaping that to the length and width of the kit engine block, simply center the top end part to the heightened block. Visually, it worked very well, gave at least the visual appearance of the real thing (with two individuals here each having 255 Offenhauser engines--long time racing mechanic Bob Higman, and racing photographer/memorabilia collector Ed Hitze Sr and of course, a race car museum and restoration shops only 65 miles SE--Indianapolis Motor Speedway of Lafayette, having several 255's in race cars, on display and on stands in the restoration garages we did have a lot of references at hand!)

Bear in mind though: Every different displacement Offenhauser has it's own set of external dimensions. Given that they were all built with block and crankcase as separate units, the longer the stroke, the taller the block and the wider (fatter) the crankcase). Even if the old Monogram PC-1 Midget (which I think is 1/20 scale BTW) engine would fit in a 1/25 scale model for length, it's way too tall proportionately. This is because while Offy engines for larger race cars had 5 main bearings, the 91-, 110, and 120-cubic inch Midget Offies had just three mains, which made for a crankcase at least 4 to 5 inches shorter, and a shorter block (front to back) in the bargain. Also, the stroke of all those sizes of midget Offies is much shorter than even the 220cid sprint car Offy, the block is shorter, but the cam towers are still nearly as tall as on the larger engines.

If I didn't have a couple of Chris's excellent resin engines still in my stash, I'd probably just go back to the way we here figured out back over 40 years ago, certainly for a classic late-60's through 1966 255cid normally aspirated Offenhauser 4.

Art

Art what bore / Stroke does the Etzell Offy Represent based on the above information.

Also did AJ Watson's roadsters (64 Foyt Winner) have a shorter height?