Silly question......and a real question.

[wolfee]

Why do they refer to a racing Merlyn engine as a "mouse engine"?

I have heard referance to this several times. Mostly refering to Strega.

Also what is the diferance between the RR 7- and the RR 9-. I know the 9- is the racing engine. But what is the advantage of the 9- over the 7-?

Thank you

Wolfee

[BellCobraIV]

Mouse motor

Wolfee,
During the high powered times of the great Bear/Strega wars some thought was given by Tiger on putting a Griffon in the Strega, Dwight Thorn replied to Tiger they did not need a Rat motor (refering to the Chevrolet big block) when they could do the job better with a Mouse (refering to the Small block Chevrolet). So the Allison rod Mouse was born and developed by Dwight Thorn. Therefore a true Mouse is a specialised racing Merlin developed by Dwight Thorn. The engine that Mike Barrow built for the Strega even though it was very similar to the Mouse is a Sparrowhawk because that is what Mike has named his creation, as compared to a mouse that would have to have been built by Dwight Thorn.
The -7 Packard built Merlin was a mid phase developement of the Packard built Merlin engines, And the -9 packard built Merlin was a late Phase developement of the Packard built Merlin engines. They differed basically in Supercharger ratios and oiling as the major differences. just to keep it simple. Most Racing engines today use the Transport Head and banks instead of the -9 or -7 heads and banks because the Transport stuff is more heavy duty.
John Slack

[GregS]

Hey BCIV....it seems somewhere in the past a race buddy of mine indicated the Allisions/Merlins had 6" rod length..ie: couldya use a set of S.B. "good" rod blanks like Carrillo or others..?

Got no idea....but I'm sure you could set me straight.

Regards,
Greg

[Unregistered]

Mouse & Mini-Mouse

So what's the diff between a Mouse Merlin and a Mini-Mouse Merlin. At least I think I've seen Mini-Mouse in print...Thanks

[Unregistered]

As for the first question? no. Both merlins and allisons use a fork & blade style rod. It is much more complicated than a traditional rod.The rods from a left and right cylinder connect to the same crankshaft journal.

As for the difference between a mouse and a mini-mouse.
A mini-mouse does not have the allison rods. But only the engine builder knows all the quirks ,bells and whistles in that sucker!