MC1 drive and I6 motor compatablity

[archbuilder]

I have a 71 MC1 drive that appears to be in good shape. It was mated to a 4 banger, that has a cracked block. I was looking for a 4.3 with an alpha to replace the entire set up, when I came across a 69 I6, complete with manifolds, carb, alternator, etc. The guy with the motor is coming through town on Tuesday with it, and says was rebuilt and has been in his garage for 20 years. I'm planning on scoping it to see what it looks like, but if it pans out it seems like a good deal.

My question is, I'm assuming that bolting it up to my drive should be fairly straightforward. I'm assuming the engine mounts. dog house and other "boat" related items will need to be modified, but I'm thinking the engine / drive set up should work fine. Is that correct or am I buying another boat anchor, lol

 

[pureinsanity]

I am thinking I read that the gear ratio was different in the out drive between a 4 and 6 cylinder. Someone on here should know and I will try to find were I found it also.

 

[alldodge]

I have a 71 MC1 drive that appears to be in good shape. It was mated to a 4 banger, that has a cracked block. I was looking for a 4.3 with an alpha to replace the entire set up, when I came across a 69 I6, complete with manifolds, carb, alternator, etc. The guy with the motor is coming through town on Tuesday with it, and says was rebuilt and has been in his garage for 20 years. I'm planning on scoping it to see what it looks like, but if it pans out it seems like a good deal.

My question is, I'm assuming that bolting it up to my drive should be fairly straightforward. I'm assuming the engine mounts. dog house and other "boat" related items will need to be modified, but I'm thinking the engine / drive set up should work fine. Is that correct or am I buying another boat anchor, lol

Would not swear to it but I think it will fit. That said I would not go that route. You have an unknown engine which has sat for 20 years. I would look for a long or short block and rebuild what you have.

 

[thumpar]

The ratio will be wrong. Also some of the early ones used different drive shaft lengths so that could be an issue that you need to check.

 

[archbuilder]

I thought the gear ratio was different, but I may give it a whirl just to see if I can get the old girl running. I know it is "rigging", but it seems like you could up the pitch on the prop to compensate for the gear ratio to certain extent. I'm sure it wouldn't be as efficient. Is that correct? Right now I just want to get the girl running to see if I even like the hull. Thanks for the info an thoughts.

 

[archbuilder]

Alldodge I hear you on the motor setting around. I'm going to stick the endoscope in the plug holes for what its worth. I figure for a few hundred it might be worth a gamble or I might be wasting money.

 

[Bt Doctur]

inline 4 is 1.98-1 .inline 6 is 1.65-1

 

[Bondo]

I thought the gear ratio was different, but I may give it a whirl just to see if I can get the old girl running. I know it is "rigging", but it seems like you could up the pitch on the prop to compensate for the gear ratio to certain extent. I'm sure it wouldn't be as efficient. Is that correct? Right now I just want to get the girl running to see if I even like the hull. Thanks for the info an thoughts.

Ayuh,.... It depends on the prop pitch ya started with, 'n the pitch ya need to get where ya wanta be,....

Generally speakin', easily available prop pitches run from 15" to 23", maybe 25",....

If the 4 banger is runnin' a 21" or 23", yer gonna run outa numbers,... before ya tame the rpms of the bigger motor,....

 

[archbuilder]

I looked at the prop that was on the 4 banger today. I twas a 19 so there maybe a little room to grow, assuming the 19 was the sweet spot for the 4 banger. Since the main goal is getting the old girl on the water, I'm going to give the 6 a whirl with this drive (assuming it is as advertised) If I like her after a season, then I will either change gears or maybe upgrade to an alpha and a 4.3. Thanks for all of your input! I'll let you know if it does bolt up to the drive or if there are issues with that part of the swap.