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Raze
Raze HalfDork
3/28/10 8:24 p.m.

I remember reading about Indy car engines running single piece engine/head without head gaskets thus allowing much higher compression ratios. Also something about using this for rally with ridiculous high boost. Am I crazy, am I making this all up? I couldn't find anything searching around the net, any resources appreciated!

Streetwiseguy
Streetwiseguy Reader
3/28/10 8:30 p.m.

There were lots built that way in the early days. Gasket construction wasn't up to the pressures. I think one of Jay Lenos recent vids has them working on one- Hispano Suiza, maybe.

motomoron
motomoron Reader
3/28/10 8:32 p.m.

Saito 4 cycle model airplane engines and designed with the head integral to the cylinder casting. They're reliable, solid engines but not the highest performing.

http://www.saitoengines.com/

Junkyard_Dog
Junkyard_Dog HalfDork
3/28/10 9:02 p.m.

Some Millers were like that iirc.

oldopelguy
oldopelguy Dork
3/28/10 9:12 p.m.

Probably thinking of the Offy engines that used to run in Midgets:

Cool little motor. Saab also patented an engine with similar configuration as a variable compression motor just a few years ago. wonder who gets that patent now?

Trans_Maro
Trans_Maro Dork
3/28/10 10:16 p.m.

Offy's weren't just in Midgets. They pretty much dominated the Indy 500 until the Europeans came along.

In "The Unfair Advantage" Mark Donohue mentions the Ferrari 512 (race car) didn't use headgaskets. Apparently Ferrari got a bit snotty when the guys at Traco complained that the power was down because of the combustion leaks.

I thought ACVW's had no headgaskets.

Shawn

mad_machine
mad_machine GRM+ Memberand SuperDork
3/28/10 10:53 p.m.
oldopelguy wrote: Probably thinking of the Offy engines that used to run in Midgets: Cool little motor. Saab also patented an engine with similar configuration as a variable compression motor just a few years ago. wonder who gets that patent now?

was that the one with the "hinged" block? I guess GM owns it now

Raze
Raze HalfDork
3/29/10 6:51 a.m.

the "Offy" was exactly what I was looking for, got the boost part mixed up between rally and Indy. Anyone know if there were ever commercially available engines of this type made in the last 50 years?

Kramer
Kramer HalfDork
3/29/10 7:51 a.m.

Pot head (no, not that kind) engines can handle tremendous amounts of boost. Look up a Detroit Diesel 149-series.

Don49
Don49 New Reader
3/29/10 7:54 a.m.

Crosley and Deutsch-Bonnet used this design.

93celicaGT2
93celicaGT2 SuperDork
3/29/10 9:04 a.m.

Make your own. Nothing some backyard welding can't fix.

Raze
Raze HalfDork
3/29/10 9:07 a.m.
93celicaGT2 wrote: Make your own. Nothing some backyard welding can't fix.

Yup, that's what I was getting at, just wanted more historical background/info, has anyone on here done this? I've found some threads online, but any specific tips/tricks would be useful. I'm not going to do aluminum, that just seems way hard and I have no experience welding alum.

Thanks!

jwdmotorsports
jwdmotorsports Dork
3/29/10 11:08 a.m.
Raze wrote:
93celicaGT2 wrote: Make your own. Nothing some backyard welding can't fix.
Yup, that's what I was getting at, just wanted more historical background/info, has anyone on here done this? I've found some threads online, but any specific tips/tricks would be useful. I'm not going to do aluminum, that just seems way hard and I have no experience welding alum. Thanks!

Hmmm...........Now we're getting interesting. This isn't going to be on a challenge car is it?

m4ff3w
m4ff3w GRM+ Memberand Dork
3/29/10 11:18 a.m.
93celicaGT2 wrote: Make your own. Nothing some backyard welding can't fix.

How are you going to weld between the cylinders and water/oil passages?

93celicaGT2
93celicaGT2 SuperDork
3/29/10 12:11 p.m.
m4ff3w wrote:
93celicaGT2 wrote: Make your own. Nothing some backyard welding can't fix.
How are you going to weld between the cylinders and water/oil passages?

Well... blown head gaskets, and gaskets in general become issues when they blow out. If there's no way for the gasket to escape, or anywhere for the gases to go outside of the motor, you probably wouldn't have to welded those areas. I would switch to a metal headgasket at that point, though, and use some heavy duty head studs/bolts to really crank the sucker down, then weld away on the outside.

That may be flawed logic.

ansonivan
ansonivan Reader
3/29/10 12:34 p.m.

Assuming a pot head engine could be built from a conventional two piece design all of the other engine components would need to be beefed up to handle the massive boost and even then, you know this thing is going consume pistons and rings like a stoned college kid eats Doritos.

Raze
Raze HalfDork
3/29/10 12:44 p.m.
m4ff3w wrote:
93celicaGT2 wrote: Make your own. Nothing some backyard welding can't fix.
How are you going to weld between the cylinders and water/oil passages?

I was thinking more of closed deck motor, have head and block machined to match, machine groove around each water/oil passage on head, put in crush ring just large enough (this is the tricky part), bolt head in place w/o HG (def non-interference motor to start), weld head to block.

Raze
Raze HalfDork
3/29/10 12:45 p.m.
ansonivan wrote: Assuming a pot head engine could be built from a conventional two piece design all of the other engine components would need to be beefed up to handle the massive boost and even then, you know this thing is going consume pistons and rings like a stoned college kid eats Doritos.

How many miles does a challenge car run

ansonivan
ansonivan Reader
3/29/10 12:50 p.m.

Very good point, I would love to see/hear/smell someone pull this thing off... bonus points for using a diesel engine.

Kia_racer
Kia_racer Reader
3/29/10 12:57 p.m.

Valves are going to be a pain to change.

Shaun
Shaun Reader
3/29/10 1:04 p.m.

Perhaps this is obvious: The Offy motor was cast as one piece. The secondary machine work on the combustion chamber, valve seat insertion, valve seating, yada yada yada was done with tooling that reached into the head through the block. Many years ago I was acquainted with Stan Smith, Son of OG hotrodder Clay Smith. Stan worked for Offenhauser building the "Offys". He described the machining process to me.

Raze
Raze HalfDork
3/29/10 2:16 p.m.
Shaun wrote: Perhaps this is obvious: The Offy motor was cast as one piece. The secondary machine work on the combustion chamber, valve seat insertion, valve seating, yada yada yada was done with tooling that reached into the head through the block. Many years ago I was acquainted with Stan Smith, Son of OG hotrodder Clay Smith. Stan worked for Offenhauser building the "Offys". He described the machining process to me.

Please elaborate

MadScientistMatt
MadScientistMatt Dork
3/29/10 2:45 p.m.
93celicaGT2 wrote: Well... blown head gaskets, and gaskets in general become issues when they blow out. If there's no way for the gasket to escape, or anywhere for the gases to go outside of the motor, you probably wouldn't have to welded those areas. I would switch to a metal headgasket at that point, though, and use some heavy duty head studs/bolts to really crank the sucker down, then weld away on the outside. That may be flawed logic.

The gasket can still go from one cylinder to another...

Raze
Raze HalfDork
3/29/10 3:25 p.m.
MadScientistMatt wrote:
93celicaGT2 wrote: Well... blown head gaskets, and gaskets in general become issues when they blow out. If there's no way for the gasket to escape, or anywhere for the gases to go outside of the motor, you probably wouldn't have to welded those areas. I would switch to a metal headgasket at that point, though, and use some heavy duty head studs/bolts to really crank the sucker down, then weld away on the outside. That may be flawed logic.
The gasket can still go from one cylinder to another...

That's why you'd have to get steel rings placed into grooves in both the head and block, least that's what I'm thinking, but then the need to weld it together diminishes...

I really need to think about how to accomplish what i'm going for here beyond machining the whole thing.

93celicaGT2
93celicaGT2 SuperDork
3/29/10 3:26 p.m.
MadScientistMatt wrote:
93celicaGT2 wrote: Well... blown head gaskets, and gaskets in general become issues when they blow out. If there's no way for the gasket to escape, or anywhere for the gases to go outside of the motor, you probably wouldn't have to welded those areas. I would switch to a metal headgasket at that point, though, and use some heavy duty head studs/bolts to really crank the sucker down, then weld away on the outside. That may be flawed logic.
The gasket can still go from one cylinder to another...

And there's my flawed logic.

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