'76 Ford 302 188hp engine rebuild

[blackhawkdown]

I've searched this forum first before asking the question and don't see the question so here goes. Had the block boiled out and fluxed to make sure there were no cracks. There were none, but two cylinders have rust at the top enough that they need bored out or honed. Owner of machine shop says he can take it from .003 to .006 oversize just doesn't know how much to take it to just by looking at the rust pitting. I believe I've only seen .003 sized pistons for my engine which means if he has to take it to anywhere over .003 the block is no good ??? unless ..... there are other oversized pistons that I just can't find. Anyone seen or know where to get pistons more than .003 oversized? Don't want to tell him it's okay to go past .003 if necessary to get out pitting and then not have pistons to fit cylinder.

 

[aerobat]

Re: '76 Ford 302 188hp engine rebuild

hey !

cannot answer in specific to your question beyond a 76 block is now 37 years old and time moves on. no parts, no knowledge, these engines blocks are garbage. i recommend to find sn oldtimer pro or repower with a newer engine.

 

[bonzoscott]

Re: '76 Ford 302 188hp engine rebuild

Hey! .003-.006 would be more like a "Hone" not oversize. If you and your machinist mean .030 or .060 over, then you may want a second opinion (machinist). He should be able to tell how far drillin it needs. And maybe things have changed alot today, but I would think oversize 302 pistons should be widely available in either size (something else machinist might know).

 

[achris]

Re: '76 Ford 302 188hp engine rebuild

You do have another option, sleeving. If the pistons you have are in good shape, just bore out the bad cylinders and fit standard size sleeves... That leaves you with a 'standard' engine, and using your old pistons...

Chris.........

 

[achris]

Re: '76 Ford 302 188hp engine rebuild

hey !

cannot answer in specific to your question beyond a 76 block is now 37 years old and time moves on. no parts, no knowledge, these engines blocks are garbage. i recommend to find sn oldtimer pro or repower with a newer engine.

Not really. Although Merc stopped using the Ford blocks in 1977, Ford continued to make the 302, in automotive applications, until 2001. And as a race application engine until 2008. So parts, service and knowledge are still pretty good....

 

[blackhawkdown]

Re: '76 Ford 302 188hp engine rebuild

Yeah, I meant .030 - .060, sorry, wasn't looking at how many zeros I put in. I was thinking about putting in sleeves if necessary. Trying to keep costs down. When it comes to automotive pistons versus marine is there no difference? I wouldn't think so but I know more about automotive than marine parts. The whole boating thing is new to me but I've caught the fever for boating.

 

[achris]

Re: '76 Ford 302 188hp engine rebuild

Yeah, I meant .030 - .060, sorry, wasn't looking at how many zeros I put in. I was thinking about putting in sleeves if necessary. Trying to keep costs down. When it comes to automotive pistons versus marine is there no difference? I wouldn't think so but I know more about automotive than marine parts. The whole boating thing is new to me but I've caught the fever for boating.

:facepalm: I hope you have deep pockets and an understanding wife. :lol:

If you want to use automotive pistons then make sure you get the heavy duty ones. I would think sleeving a couple of cylinders and using your original pistons would be quite a bit cheaper then a full set of new pistons...

BTW, not recommended to oversize a marine block more than 30 thou...

Chris.....

 

[theblob]

Re: '76 Ford 302 188hp engine rebuild

Yeah, I meant .030 - .060, sorry, wasn't looking at how many zeros I put in. I was thinking about putting in sleeves if necessary. Trying to keep costs down. When it comes to automotive pistons versus marine is there no difference? I wouldn't think so but I know more about automotive than marine parts. The whole boating thing is new to me but I've caught the fever for boating.

People do .060 all the time.since your not putting it in a car you dont have to worry about the overheat issue.you can get alot of hp out of a 302 the best engine ford has made.it can hang with the 5.7 350 gm motor.very reliable,parts are just high.

 

[theblob]

Re: '76 Ford 302 188hp engine rebuild

Building a ford motor sure can get exspensive compared to gm.only problem ive ever seen with the 302's are to replace timing chain earlier than what called for,but you already started it so if you got the cash go for it.i always wanted to build a 302 its like the energizer bunny keeps going and going.nice motor definitly not junk.

 

[achris]

Re: '76 Ford 302 188hp engine rebuild

Yeah, I meant .030 - .060, sorry, wasn't looking at how many zeros I put in. I was thinking about putting in sleeves if necessary. Trying to keep costs down. When it comes to automotive pistons versus marine is there no difference? I wouldn't think so but I know more about automotive than marine parts. The whole boating thing is new to me but I've caught the fever for boating.

Just had a quick search on the web... A full set of oversize pistons will cost you anything from $300+, and you would still have the cost of boring every hole. Sleeves are less than a $100 each.

People do .060 all the time.since your not putting it in a car you dont have to worry about the overheat issue.you can get alot of hp out of a 302 the best engine ford has made.it can hang with the 5.7 350 gm motor.very reliable,parts are just high.

Against my better judgment I'm going to respond to this. :facepalm: 'People' might do 60 thou all the time, but for marine application, it is not recommended to go more than 30 thou. (look at the Merc recommendations for oversize pistons, nothing over 30 thou. In fact, for the 302, nothing over 20 thou)...

As for overheating. You need to be MORE vigilant about a boat engine than a car engine. An engine in a boat is working significantly harder then the same engine in a car. It's been equated to towing a trailer up a steep hill, at 80mph.... And the boat engine is doing that ALL THE TIME!!!

The Ford 302 based engines in the Mercruiser guise only ever produced 225hp, a far cry from GM's 350 at 260hp...

Chris........

 

[haulnazz15]

Re: '76 Ford 302 188hp engine rebuild

The 302/351w is a time-tested/proven engine. It runs head-to-head with the GM SBC in terms of power and reliability. Easily one of the best engines Ford ever made. That being said, I don't think I'd bother sleeving anything, and I wouldn't go more than .030 overbore on a marine engine. You can buy a complete reman long block for $1300 or so, and you might have that much in machining and parts costs by the time you go through everything. I was in a similar situation a few years back with an engine that had some water in a few cylinders that sat for a while. Would have needed two sleeved cylinders. Even though I knew the engine was in great condition otherwise, I decided to scrap the engine and go with a reman unit.

 

[haulnazz15]

Re: '76 Ford 302 188hp engine rebuild

hey !

cannot answer in specific to your question beyond a 76 block is now 37 years old and time moves on. no parts, no knowledge, these engines blocks are garbage. i recommend to find sn oldtimer pro or repower with a newer engine.

Well, although your handle references Cessna aircraft (pilots are generally a knowledgeable group), you seem to know little about automotive-based engines. Parts for the 302/351w (same block) are just about as easy to find as they are for any GM 350. The only parts that can be problematic are some miscellaneous brackets (which aren't wearable-items) that are Mercruiser-specific, but can still be found easily on eBay or craigslist. The 302/351w was used in tons of cars/trucks all the way through 1996, when the Triton-series engines came out. There are literally tens of thousands of vehicles running around with the 302/351w engine which are still running strong.

 

[hivoltg]

Re: '76 Ford 302 188hp engine rebuild

I have a 351w in my boat and I have not had any trouble finding marine parts for it.

Im a GM guy but I have been very impressed with this Ford motor.

*To the OP: I see plenty of oversized piston sets new in the box with rings on ebay for pretty cheap*

 

[RCAnderson]

Re: '76 Ford 302 188hp engine rebuild

I went .060 over on my 302. No difference in cooling that I could detect. (closed cooling) This will definately be the last rebuild on that block though. Not sure yet if I'll go with another 302, or bump up to the 351. Unless a guy was to replace the rest of the transom assembly, those are the only options.