Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
saw core to mc10 clone advise
#1
this is somethjing mike saved that i posted who knows when. so i'm reposting here. i'll add to it as i feel like it the post was pretty basic.

MC10 conversion from saw


mc10 from saws is simple.
find and buy one mc1-70 or mc1-80
also find and buy one mc d44.
remove powerhead from both saws.

take head outside fan cover flywheel and shroud cover off d44 powerhead.
Chuck the rest except maybe the coil and inner cover especially the points.

on the mc1-70
break down powerhead rebuild engine with new bearings and piston sized for a nice round bore.
the crank is a mc10 1-70 or 1-80 crank all the same.

sell the outer cover and head on ebay or use on newer super series motor.
pick the nicer of the two flywheels if they are both mc10 style.
pick nicer working coil and inner cover.

if you use the d44 inner cover you'll have to copy the relief cut for flywheel wt. clearance at the top of the round bearing carrier that is in the block.
easier to see difference with both in hand.
stick motor back together with d44shroud outer cover and head.
voila mc10.
if you're really sneaky you can cross out the mc1-70 or 1-80 and restamp mc10.
no way to tell any difference then. Dodgy

if you just want a really nice same spec clone you can use a mcs44a or mcs55a instead.
to almost anybody but me or ron cubel there is no difference.
the difference is the block lacks material for the relief cut to allow bigger counter wts of the later mc10 cranks.
it is visible outside.
 the "true/real" mc10 block's have a cast in raised area around the pto side on the block for the flycut for bigger counter wt clearance relief.
the earliest mc10's were actually made from s55a's by jimmy y , but as of yet i've seen none in person .
dave
Dave L.
Reply
#2
Further info,
  •  to convert to a kart motor the intake manifold will have to be replaced with a kart intake manifold. use only early kart manifolds. the newer versions made for mc9-91 series motors are longer and won't fit up easily or work well if made to fit.
  • the stuffer will also need to be replaced a super series motor stuffer will fit nicely.
  • often the points are difficult to find. several pointless ignitions have been fitted with good success.
  • either the original saw piston may be used (it was the early mc10 piston) or a thin ring mc10 kart piston can be used instead. if you want a low buck alternative to replacing the piston you can de-temper the low ring and carefully cut a thin relief slot into the top ring to simulate two thin rings stacked with a spacer.the reduced drag will be nearly as good as a kart thin ring piston.

secondary modification of parts
  • replace the older style con rod #55009 with a newer mc91 style rod #47903. the later rod is considerably more reliable.
  • any super series stamped tin block/head cover will fit up to the motor. the same applies for the side cover standard super series side covers fit up nicely though will look incorrect on a mc10.it is possible to skip buying a d44 and use the head found with the saw motor if you happen to have these parts or another point you can modify the saw head cover to do the same job with some removal of excess cast metal.
  • the motor can be nine ported and exhaust opened if desired that will add serious horse power if done correctly. RESEARCH the subject before doing anything.just randomly trying to "improve " porting without knowledge is the best way to ruin a good motor.
Dave L.
Reply
#3
Dave L: 

I am planning to do a conversion later this year or early next year. My grandma is finishing her house and I'd like to get a kart there. But that means I need an engine too. So as a low buck alternative making a rep. mc10 would be a lot of fun. However I have a few questions. 

1: Could I get away with just using one chainsaw to make the replica? I'd need newer parts so I'd like to keep it as low budget as possible. 

2: Would it be possible to use something like a 1-71 and call it a replica stroker mc10? Can these blocks even be made into mc10's?

And last, 3: What parts do you suggest for reliability, but fun and cheap. Would it be a good investment to get things like a new crank or bearings, seals etc. or maybe a new flywheel and piston or even a rod?

Dave, I can't thank you enough in advance. I'm new to the karting world so I end up having a lot of questions.

Thanks!

Vico
Reply
#4
Vico........on the old Forum there were many posts on how to convert Mac Saws....the topic went on and on......if you look over all that Dave has posted on Mac's here....you may be able to paste it together ?

Here's a topic over on the Saw website that may give you some info too.

Steve Welte and others have also posted info on Facebook, U-Tube......but I don't have links for you Sad .

https://www.smokstak.com/forum/showthread.php?t=68489


Attached Files Thumbnail(s)
   
Reply
#5
Randy:

I will search for other posts and will do a bit more reasearch before purchasing a saw and converting one. I remember the post on converting a saw to an mc49 clone but for backtrack farther.

Have a fantastic night watching the oscars! Smile

Vico
Reply
#6
here's a nice example of a MC-10 clone.
Built from a 1-70 block, which was the starting point for many MC-10 engines.  
The only difference is the 1-70 number is not X'ed out and it doesn't have MC-10 stamped on the oiler boss.
9 ported with one finger port ,  bored .040 over.  
The intake and exhaust ports are slightly modified.
It has a  HL189 period correct carb.  


This mc10 clone is a excellent example of what can be done with the correct saw parts.


below is general specification information anyone considering building or buying a mc10 clone.
The tin cover head and outer cast cover are typically gotten off a second saw the d44. 
of course the original mc10 kart parts also work.

the d44 is NOT acceptable used by itself to make an mc10 clone .
 it will look almost exactly the same on the outside but it is much smaller internallymaking the d44 a weaker lower performance motor  .
the d44 has a 1.375 stroke instead of the 1.5 mc10 stroke and only 22 connecting rod bearing instead of 24.
 the d44 alone can't be used to make an mc10 clone.

For a mc10 clone no short block can be used besides a mc s44a , mc s55a , mc 1-70 or mc1-80 .
only those four saw blocks and cranks are be used  to make a correctly built mc10 clone.

external parts that are kart only would be any period correct manifold exhaust and stuffer cover.
d Cool


Attached Files Thumbnail(s)
       
Reply
#7
just saw this i really haven't been trolling all the pages as i should.
first who ever said building a mc10 clone is cheap i never did.
i set out to build clones because i simply couldn't find enough mc10's to suit my taste.
so i figured out exactly which saw parts would fit.
it took a while because the guys who did know what parts to use weren't really generous with information.
so firstly,  making a mc10 clone is not cheap.

it will cost around the same as a "real" mc10 by the time you're finished .
the difference is saws typically have gotten butchered or totally used up.
they tend to have clean bores and the porting is nearly always stock.

the reason you use at least two saws.
mc10 clones aren't a true clone if you start omitting important parts.
the d44 provides the correct center plug head ,tin shroud , coil and outer cover.
very few mc 1-70's came with a center plug head and no 1-80's i've ever seen had them.
the s44a and s55a all have side plug heads.
you want to add a thin ring piston if you want to go fast and the other kart parts need to be added.

as with any recreation or restoration you may need to buy several parts donors to get decent clean parts.

recreating the mc49 is much easier typically you switch the crank and piston and you're done if all the ports are drilled.
easier yet is building a mc49 saw/kart motor.
with those you use a clutch suited for a stub crank and switch the piston.
of course the intake manifold, stuffer and motor mount need to be added. often the saw exhaust is fine for a mc49.

anyway my point is that we build the clones not so much for saving money as to add more kart engine inventory to the world in general.
they ain't making mcculloch kart motors anymore so we do what we gotta do.
hope this helps
d Cool
Dave L.
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)