Fast Fred's Secrets of the OMC MOD50's Thread #1

[David_L6]

David L6, the Mod 50 porting requires an exhaust system which is matched to the port timing. Without the correct exhaust the higher ports will just hurt your bottom end with little help at the top. Note the ports are chamfered from the basic port section to the timing edge. This was done to maintain as much bottom end power as possible and still perform well at higher rpm.

I have a factory Mod 50 exhaust and part of an exhaust that is similar to the factory Mod 50 exhaust that was built by Ray Nydahl. I am hoping that one of those will run well on a non-factory tower. I'm not yet sure what kind of tower I'll use.

[Fast Fred]

way good stuff , as i understand it , the removeing of the rib is commin in one and two , i was thinkin thats ware thay was try in to go with it, way cool stuff

thinkin Davidl6 got some Mod50 exhaust parts, gots any pics to share, i don't have any pics of mine, thay went right to the dyno shop, never saw them, just pics.

[Jeff Akers]

Great thread guys !

MORE...MORE... MORE !!!

[Jeff Akers]

I have a factory Mod 50 exhaust and part of an exhaust that is similar to the factory Mod 50 exhaust that was built by Ray Nydahl. I am hoping that one of those will run well on a non-factory tower. I'm not yet sure what kind of tower I'll use.

David,

You should have sold that "THING" to me a long time ago!

I think it would flow nicely on my mid

[Fast Fred]

well gots to go for now , gots more hear, see what else we can see
or maybe i'll see yous in FL, at the airport i herd, someware

[NERSTROM]

David,
Not sure if you have to exhaust through the midsection or can run an open stack. The motor Fred used for the Mod 50 record had the exhaust into the midsection because of the rules for Mod 50. We could have just as easily made a system which came out above the midsection. We also raced this setup at the alky nationals in Minn. If you want to use one of the cast systems use the OMC parts. Ray's system did not require machining the block and compromised the exhaust passage. Look very closely at the rest of the Mod 50 system when you design yours, especially the area ratios. You will be surprised by what you find.

[David_L6]

David,

You should have sold that "THING" to me a long time ago!

I think it would flow nicely on my mid

I like the looks of your exhaust! I bought that thing for a knucklhead over in Mississippi while I was chasing parts for him......

[David_L6]

David,
Not sure if you have to exhaust through the midsection or can run an open stack.

I can run any tower and any exhaust. No rules on those.

[David_L6]

David,
Look very closely at the rest of the Mod 50 system when you design yours, especially the area ratios. You will be surprised by what you find.

If you knew me, you'd be surprised if I found anything. I don't have a clue what I am supposed to be looking for and probably wouldn't realize I was looking at it if I was looking at it.

[Fast Fred]

on the exhaust, the distance from the port to the back of the exhaust plate is grater, the spent charge turns once (down)