Marine 302 block

[Twizzler09]

So I sent a 302 block off to the machinist to be cleaned up and de-rusted, in prep for a v8 swap.....but it turns out its no good. It cleaned up real nice and woulda been useable, but alas someone overheated the sh*t out of this thing and cylinder 8 is cracked in four places.

So I got to talking with the guys there about alternatives, and it turns out they have a 302 block laying around thats in awesome shape, no rust, doesnt even "need" to be bored out, but it came out of a boat.

So my question is, is there any major differences between a Marine 302 block and a normal automotive style? Several people, including the machinist, have told me that the crank, bearings, etc from a normal automotive 302 fit right in, and that the only difference is that the marine style is just thicker overall?

Any input would be awesome

 

[Maverick]

There is no difference between the blocks, they're exactly the same. If the boat has been used at all in salt water walk away from it. Otherwise I'd say go for it. If the heads that came off the marine motor are laying around check them out to, some marine 302's came with GT-40 heads.

 

[Rinny650]

Only differences I know of are the marine engines have special cams for them and lifters and intakes. Should be fine

 

[Twizzler09]

Just looking it over, seems like its identical to the one I had before. Very unlikely that it ever saw use in salt water, we're a long ways from anything that even resembles salt water too. (central-ish Illinois)

Unfortunately they dont have the heads, the guy that previously owned the block never brought them in. They only want $50 for it too, seems like a steal to me.

So it looks like I'm back in business, gonna stroke this bad boy and have some fun

 

[COPPERHEAD85]

i ran into the same scenario you have a while back with a slant six motor........came out of a boat .
only difference was it was reverse rotation from auto application,changed cams and it ran fine.

 

[v-8power]

Is the block aready bored .30 over, or is it going to need machined?

 

[Twizzler09]

Its still standard bore, and doesnt "require" boring, want to take it .030" over and use a stroker crank/rods for 347. Technically I could just re-ring it and be done with it, but wheres the fun in that?

Just to make it clear though, as long as the crank and bearings from a 302 in a truck/car fits proper, thats all I need really. (it does not come with anything besides main caps. The rest of the block is 100% bare) Thats why I wanted to make sure its the same as any other 302, getting 100% brand new internals for it. Would really hate to order it all, and go to assemble everything just to find out the journal sizes are completely different.

 

[baddad457]

The difference in a Marine 302 woudl be if it was a reverse rotation motor. Then the difference is the oil control knurling at the rear main seal. That would also be reversed to draw excess oil away from the seal. If used in a std rotation, it would push oil toward the seal. The cam would also be ground differently as was previously pointed out.

 

[Twizzler09]

The difference in the oil delivery wouldnt make it impossible to use an oil pump made for an automotive engine, would it? Basically what I want to know is if I can throw a rebuild kit made for a 5.0 out of a truck or car in it, and it work. (Cam, lifters, bearings, oil pump, crank, etc).

Failing all else it'll be a fun expirement.

 

[baddad457]

Blocks are all the same.

 

[Captain Ledd]

I have a boat engine in my Ranger.

Came out of an '82? T-bird, though apparently they never came with a 302 in those years. After much searching based on a weird casting number, it was determined it came out of a boat. It moves along pretty well

I have also heard they have the better heads and a hi-po flat tappet cam.

 

[Twizzler09]

I have a boat engine in my Ranger.

Came out of an '82? T-bird, though apparently they never came with a 302 in those years. After much searching based on a weird casting number, it was determined it came out of a boat. It moves along pretty well

I have also heard they have the better heads and a hi-po flat tappet cam.

Unfortunately they dont have the heads or cam from this motor. Its 100% completely bare, besides main caps. Thats alright though.

Since it seems theres no real difference in the block itself, looks like its a go. Once the ball gets rolling I'll start a build thread in case anyone wants to follow the progress

 

[baddad457]

I have a boat engine in my Ranger.

Came out of an '82? T-bird, though apparently they never came with a 302 in those years. After much searching based on a weird casting number, it was determined it came out of a boat. It moves along pretty well

I have also heard they have the better heads and a hi-po flat tappet cam.

Better heads? Not in 1982. Cam ? yes, that's the one used in the 82 2 bbl HO 302 in the Mustangs.

 

[mikepotts]

marine motors no matter what make or model DO have a coating in the cooling jackets to prevent corrosion.

 

[baddis]

i hope thats not it in the back of your truck in the rain we have been getting.