M/C 470 Replacement

[a1nowell]

I currently have a M/C 470 powering my 24' tritoon. I am considering pulling the engine and rebuilding it.

MY QUESTION: What other engine would bolt up to my existing transom and stern drive, exhaust etc?
My 470 serial number is: 6684523 My Alpha sterndrive serial number is : 6664498

Thanks, in advance for any info,

Larry

 

[achris]

Re: M/C 470 Replacement

The best replacement option is a 4.3 V6. You'd have to get new exhaust Y-pipe, but the rest fits. If you were to buy an old boat with the right engine you could use all the bits from that... If the engine's tired, then there are plenty of old V6s in good condition in trucks... It appears you have the newer style inner transom plate so a late model engine flywheel housing is required.. (changed in about 1983, your engine is 1984).

Chris...

 

[a1nowell]

Re: M/C 470 Replacement

Chris,
Thanks for the info. I am afraid I do not have the room for a V6. The dog house on my tritoon is the rear section of the middle toon and I do not think I have the width.
Thanks,

Larry

 

[fmalott]

Re: M/C 470 Replacement

I currently have a M/C 470 powering my 24' tritoon. I am considering pulling the engine and rebuilding it.

MY QUESTION: What other engine would bolt up to my existing transom and stern drive, exhaust etc?
My 470 serial number is: 6684523 My Alpha sterndrive serial number is : 6664498

Thanks, in advance for any info,

Larry

what make you think you have to rebuild do you have a problem

 

[a1nowell]

Re: M/C 470 Replacement

fmalott,
Just thinking ahead and outloud. My 470 starts and runs pretty good but I cannot get it to idle smoothly at all. I had my carb rebuilt by National Carb last fall and as I said the engine runs great above 1500 rpm but below 1500 it idles rough. I pulled the plugs this morning and they were pitch black with carbon. I put new NGK plugs in and no difference. I adjust the air jets (rochester 2 brl) and it makes no difference. The engine uses a quart of oil every 15-20 hours. As I said just thinking ahead and outloud.

 

[stonyloam]

Re: M/C 470 Replacement

With it idling, try pulling the plug wires one at a time. See how that affects the RPM. you might have a weak cylinder that causes it to run rough at low RPM. If one cylinder is weak it will make little difference when you pull the wire. A compression check is the next step. Could be a head gasket problem, often a problem with 470's. As for another engine, IMHO rebuilding your 470 is the better option, if the bottom end is in reasonably good shape.

 

[riskibusiness]

Re: M/C 470 Replacement

How rough does it idle. My 470 has a 2 year old rebuild and it idles a little rough as I understand it its just the way these are

 

[a1nowell]

Re: M/C 470 Replacement

The idle really smoothed out when I reversed the #3 & #4 wires on the distributor cap. Guess I'll wait a while for the rebuild.

 

[Bondo]

Re: M/C 470 Replacement

The idle really smoothed out when I reversed the #3 & #4 wires on the distributor cap. Guess I'll wait a while for the rebuild.

Ayuh,... :facepalm: