Mercruiser 470 internals?

[Eric H]

Does anyone know exactly which parts are made by Ford? I see my rods are Ford and I've read the head is as well.<br /><br />Are the pistons and main bearings Ford 460 parts?

 

[Laddies]

Re: Mercruiser 470 internals?

it's a TRW crank parts are listed on iboats, sietta and most other parts suppliers

 

[Don S]

Re: Mercruiser 470 internals?

One note for you guys rebuilding any of the Merc 3.7L engines, there is a special oil pump alignment tool required to align the oil pump with the distributor. If you don't get it right, you will break the oil pump drive shaft off the distributor, and loose oil pressure. <br />I used to see this a LOT, years ago when there were more of those engines around.

 

[Rod Holder]

Re: Mercruiser 470 internals?

Hey Eric,<br />Yes, the head is 460 Ford, as are the rods. I tried to go the Ford part route when I rebuilt my 470, but in the end, it was easiest to go thru ebasispower.com. They have everything you would need. The parts are namebrand (sealed power, melling etc...)Free shipping over 100 clams also. I agree with what Don S says (although I aligned my oil pump to the distributer another way).<br /><br />Good luck with your build.....Jon

 

[Eric H]

Re: Mercruiser 470 internals?

Jon,<br /><br />are you sure about that link? <br /><br />thanks for the input guys.

 

[Don S]

Re: Mercruiser 470 internals?

http://www.ebasicpower.com/

 

[Rod Holder]

Re: Mercruiser 470 internals?

Sorry about that typo. Cheetos and typing do not mix. dougrussell.com is another source.<br /><br />Have a good one.

 

[Eric H]

Re: Mercruiser 470 internals?

I'm getting confused here. The motor I took apart had 3.7 on the valve cover but the serial number indicated it is an older 470 block. I assume it has been rebuilt before. <br /><br />My delimma is that the pistons removed from the motor have 2 valve reliefs. If I look at a Silvolite replacement part number 3164h they spec only 1 valve relief. Can anyone shed some light here? <br /><br />Additionally, there is a 1992 Mercruiser SB that discusses 224 CID (3.7L) PISTON IDENTIFICATION, TYPE AND CLEARANCE. I can't find it online anyplace so I'm wondering if anyone has a link or can tell me what the bulletin says.

 

[WillyBWright]

Re: Mercruiser 470 internals?

The same basic motor had many designations. They all have the same 3.7L block, but different manifolds and carbs. There was the 165, 170, 470, 485, and many more. Early versions had a 3"dia heat exchanger which was barely adequate. The later models used a 4" and did MUCH better. The alternator in those are like an outboard's. The voltage regulator is extremely expensive and prone to failure due to corrosion. If yours doesn't run a belt-driven aftermarket alternator, clean those connections real good. Also clean anyplace the regulator contacts the block for a good ground connection.<br /><br />The dents on the tops of the pistons are to save the motor if the timing chain should bump a tooth or two. If it goes out of time, the valves hit the piston doing a ton of damage without those there.

 

[tfjrc2]

Re: Mercruiser 470 internals?

I agree with what WillyB says about the infernal internal alternator.....In fact, take it from someone who had one and get the external kit while you have this motor torn down.<br />It will save tons of trouble later, and you might even be able to sell the boat if/when it ever comes to that.<br />Many guys will not buy a 470 without the external alt kit and 4" cooling.

 

[Eric H]

Re: Mercruiser 470 internals?

Thanks for the info. I'm really just interested with the internal specifics. What I've found thus far are only minor changes between models. The pistons, several variations, were changed from cast to forged in the later models. I had originally thought about using a 460 piston, however, I don't think I will due to slightly different compression heights and the Merc piston pin boss being centered. The 460 piston would probably work fine but I'm not building an experiment.<br /><br />I still don't understand why Silvolite lists the Merc Piston as only having 1 valve relief. Maybe this is a typo in thier specification.

 

[Rod Holder]

Re: Mercruiser 470 internals?

Eric,<br />The pistons I got from ebasicpower.com were Sealed Power and were exactly the same as what came out of my 1977 version (470/3.7/224).There were two reliefs. They were on both fwd and aft but on opp. sides (maybe to insure that if they were installed wrong, there would still be clearance for the reason Willy states)<br />Save yourself some time and see what oversize pistons sizes ebasicpower has and let your machine shop know what you have to work with. <br /><br />Like I said, I comparedspec's for both the Merc 470 and the Ford 460 and there were enough slight differences that I did not want to risk putting in main brgs for example that were "pretty close".<br /><br />As a bonus, the time you save could be spent knocking back a cold one, while admiring your completed build on the stand.<br /><br />Hope all goes well.....