Mc45D......was it real!!

[Ronald Cubel]

Isn't the Mc45 9 ported? The 91 piston should work good? Lets here it from the engine guys?

[Scott Kneisel]

Yes, the 45 is 9 ported so the 91 piston would be good. I like Bills idea of stuffing the old 3rd port channel that the 45 still had but the wall was cut away to allow fuel to get into the 9 ports because the piston had a full skirt. Using the 91 piston with cut away skirt allows fuel to get to the boost ports from the crankcase so that old channel could be plugged to stuff the crankcase a bit more.

I remember some aftermarket old manifolds had a plug that went down into the 3rd port slot. It was not appropriate for the 3rd port engines but the idea should work fine for the 45 with a 91 piston. Should be fairly easy to fashion a removable plug like Bill suggested.

[david a luciani]

you could probably cast it out of molder liquid rubber that we use for white metal castings and to make core negative castings.
can't recall the name exactly but it was a two step that you'd use for exact contours.
when it has cured you need to cut a jam plug out so you could rove but it should handle the temps fine.
if you think it's a usable idea i'll look up the right stuff and post.
dave

[jmendoza]

Wait a minute there Steve-O, you have seen the MC-102 I have for a gas powere kart engine starter!

[Bill Hermsted]

My idea? I wish!
I just wanted to copy the mod that some brilliant kart racer thought of way back,when the third port chamber was filled in for the first time on an early nine port motor. I've never seen nor heard of that intake with the bottom plug. Was it made by one of the speed parts outfits, or home made? We know that Mac finally made a new mold for the 91 and 101 series, doing away with the third port casting.
Take care, Bill

[Rob Voska]

GEM made manifolds with a fin to block off the third port.

I saw a block and piston assembly on ebay years ago. It was a 101 with a chrome bore, holes in the bottom of the cylinder & NOS with a piston. If I remember right it was 135CC.

[Butch Kavanagh]

karting world may 1964, mail box, page 10, 'not our fault'. james sims wrote '...march issue that new macs not introduced...on the contrary, they have been out in england since oct 1963...they are the mc9 the mc45 the mc45d and the mc75....i saw this info in a foreign publication....' karting world's reply '...rushed to mcculloch's international division....the european racing authorities demand the registration any new engine by the october preceding the racing season...therefore mcculloch sent confidential specifications and engineering drawings to the authorities...no engines were sent because none were in existence....' i am not computerr smart or i would scan or whatever you do as karting world and mcculloch had other comments in their reply to this letter. i grew up in wiseco land and never heard or seen a mc45d until this thread

[Tom Smith]

Rob, Savin 101's have the 2 transfer windows on the bottom of the cylinder, a chrome bore, Forgedtrue forged pistons, and are 133 cc. They use Super Pro 125C (chrome bore) rods . I think Wiseco made some pistons for the big 101 macs too.
Back to the IPL drawing business, here's an example. Take a look at the Mc-30 IPL drawing, it details the new Mc-30 intake manifold, new intake manifold gasket etc. and Mc-30 sticker but still shows an Mc-20 head shroud, in fact the June 1970 Mc-101 series drawing shows a 101A with a 3 bolt carb and an Mc-20 head shroud still. The illustrators probably had no ideal it was narrower and for sure they didn't know anyone would care one way or the other 35+ years later.
This BS prompted me to finish putting together one of my Mc-30s so at least that's one down one to go now. I put a 40 intake on it to enhance it's performance some. I seem to vaguely recall that the R1 at McCulloch had a pair of 30s on it.
Steve, one other very minor difference with the 30 was the intake manifold to crankcase gasket was opened up at the bottom to match the revised larger intake area for the first time.
Butch, Mc-45Ds were the last 45s Mcculloch built. Tom

Mc-30 .JPG

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[lynn haddock]

[lynn haddock]