347 Cubic In ID help!

[dherrenbruck]

Is there a way to confirm you are looking at a 347 Stroker short block without tearing down? I have the opportunity to purchase the following without the original paperwork because it doesn’t exist. It’s a new short block with the following listing of parts. Would the be any kind of castings or stamped identifiers to confirm? Unfortunately I don’t own any kind of dial bore gauges. Can you use a tape measure? Would there be any marking on the crank, rods, cam and such that can been seen without taking everything apart. Thanks in advance for all your help. David.

[Jeff Kleiner]

Hi David,
Since Ford never produced a 347 there won't be any factory casting numbers or stamps. However with the heads off it's easy to measure; a 347 has 4.030" bore and 3.4" stroke. If you find a 4.030" bore with 3.25" stroke it's a 331 and 4.030" bore with 3.0" stroke is a 306.

Jeff

[mrglaeser]

I've have one of these in a 69 mustang. The Casting is the same between this and a 302 from Ford racing. One thing I can tell you is that the Boss Blocks have 4 bolt mains and a handful of extra screw in plugs for various things like oil/temp sensors that Fox/Explorer/F150 5.0s and old 302s don't. Maybe a machinist/engine builder could measure the piston skirts (they would be shorter than a 302), rod lengths (longer than a 302), and crank radius (longer than a 302). These short blocks are back ordered for more than year right now(I have 2 on order from early 2022) from Ford so if the seller claims that they recently purchased it I'd be suspicious. Great short blocks though - pretty expensive compared to a reconditioned block built short block normally.

[Geoff H]

I don’t know if the ford racing blocks have it, but my 347 is based on a 1990 5.0 and required clearance chamfers at the bottom of each cylinder to clear the connecting rod bolt. You would be able to see it quite easily if the pan is removed.

[edwardb]

Will be hard to absolutely confirm without measuring bore and stroke. But easy to confirm it's a 4-bolt main block. On the crankshaft side, the three main caps holding the crankshaft have four bolts each. Two on each side. A stock block will only have two on each side. Reasonable chance that if a 4-bolt block it's what they say it is. New or old stock? As already stated, new ones are hard to get right now.

181487

[dherrenbruck]

Hi David,
Since Ford never produced a 347 there won't be any factory casting numbers or stamps. However with the heads off it's easy to measure; a 347 has 4.030" bore and 3.4" stroke. If you find a 4.030" bore with 3.25" stroke it's a 331 and 4.030" bore with 3.0" stroke is a 306.

Jeff

Thanks Jeff. This short block if it is what the guy is claiming is $8,700 on Summit and Jegs website. I can pick it up about a third if that. I’m just concerned it might be to much engine for what I’m wanting.

[dherrenbruck]

Will be hard to absolutely confirm without measuring bore and stroke. But easy to confirm it's a 4-bolt main block. On the crankshaft side, the three main caps holding the crankshaft have four bolts each. Two on each side. A stock block will only have two on each side. Reasonable chance that if a 4-bolt block it's what they say it is. New or old stock? As already stated, new ones are hard to get right now.

181487

Thanks, I asked that originally and didn’t get an answer. I’ll ask again. David

[dherrenbruck]

I've have one of these in a 69 mustang. The Casting is the same between this and a 302 from Ford racing. One thing I can tell you is that the Boss Blocks have 4 bolt mains and a handful of extra screw in plugs for various things like oil/temp sensors that Fox/Explorer/F150 5.0s and old 302s don't. Maybe a machinist/engine builder could measure the piston skirts (they would be shorter than a 302), rod lengths (longer than a 302), and crank radius (longer than a 302). These short blocks are back ordered for more than year right now(I have 2 on order from early 2022) from Ford so if the seller claims that they recently purchased it I'd be suspicious. Great short blocks though - pretty expensive compared to a reconditioned block built short block normally.

Thanks for the great info. It’s not the engine I set out to put in my new MK4 build but if it’s what he’s claiming I can pick it up for a third what a new would be from summit and jegs. David.

[dherrenbruck]

I don’t know if you can tell anything from these photos. I wish he’d taken a photo of the bottom showing the mains. Thanks.

[mrglaeser]

I would say look at the front image of that short block with imagine in the first post. Notice there are no screw in steel plugs. I'm going to suggest this is not a Boss block. It could still be a 347 and a fresh build but it is likely not from Ford Racing. Also short blocks normally don't come with the timing components, oil pumps, and oil pans installed.

Also look at the oil pan. There is a stamping that starts with an 'F' this indicates at least the oilpan is from the nineties. Though it's hard to read it could also say F150 for a after sale Ford truck part maybe.

[Jeff Kleiner]

I don’t know if you can tell anything from these photos. I wish he’d taken a photo of the bottom showing the mains. Thanks.

Yes, the photos indicate that it is NOT as represented in your initial post. That says that it is built using an M-6010-BOSS302 block. The Boss block uses screw in core plugs as shown here on both sides, below the coolant passages:

https://performanceparts.ford.com/images/part/full/NEWBOSS.JPG

The photo of the front of the engine that your seller sent clearly shows that those plugs are not present meaning that it is NOT a Boss block therefore making any other claims suspect.

https://thefactoryfiveforum.com/attachment.php?attachmentid=181500&d=1678708528

Proceed with caution ;)

Jeff

[dherrenbruck]

I would say look at the front image of that short block with imagine in the first post. Notice there are no screw in steel plugs. I'm going to suggest this is not a Boss block. It could still be a 347 and a fresh build but it is likely not from Ford Racing. Also short blocks normally don't come with the timing components, oil pumps, and oil pans installed.

Also look at the oil pan. There is a stamping that starts with an 'F' this indicates at least the oilpan is from the nineties. Though it's hard to read it could also say F150 for a after sale Ford truck part maybe.

Great info. Thank you. I’m finding the current owner is the second owner. Bought from someone that bought it and started to complete the build and ran out of money. He Amat have been told the same info which is why he is portraying this as a ford performance boss engine. I just told him to go out in the garage and tell me if a 2 or 4 bolt main. If it’s a 2 bolt, still might be worth a couple thousand dollars. Thanks David

[edwardb]

Couple more comments from my side, in addition to what's been pointed out already, a new engine has a different look than that. Pictured below is a brand new build I had done a few years ago. A DART block. But you get the idea. Everything is new, fresh, and shiny. Including machining, etc. Your pictures look more like a refreshed stock block. Notice the discoloration in the lifter valley. Evidence of gaskets having been installed around the front cover bosses. Etc. Not a bad thing if a nicely refreshed stock block with new parts inside. But not a BOSS. If it was the genuine article, no reason to sell it for 1/3 its value. Unless some kind of an inside or family deal or whatever. Could easily be sold for much more. I'm suggesting caution. I was royally burned on my very first build with a 306 I bought off eBay. It was completely misrepresented by the seller and cost me several thousand to fix. I found out much too late for any recovery from the seller, who by then had been delisted by eBay. No surprise. BTW, a 347 is an ideal engine for these builds. Nice power in a compact size.

https://hosting.photobucket.com/albums/ab234/edwardb123/Factory%20Five%20Mark%204%20Roadster%20Build/Engine/.highres/IMG_2125_zps2a587ff4.jpg?width=960&height=720&fit=bounds (https://hosting.photobucket.com/albums/ab234/edwardb123/Factory%20Five%20Mark%204%20Roadster%20Build/Engine/.highres/IMG_2125_zps2a587ff4.jpg?width=960&height=720&fit=bounds)

[dherrenbruck]

Couple more comments from my side, in addition to what's been pointed out already, a new engine has a different look than that. Pictured below is a brand new build I had done a few years ago. A DART block. But you get the idea. Everything is new, fresh, and shiny. Including machining, etc. Your pictures look more like a refreshed stock block. Notice the discoloration in the lifter valley. Evidence of gaskets having been installed around the front cover bosses. Etc. Not a bad thing if a nicely refreshed stock block with new parts inside. But not a BOSS. If it was the genuine article, no reason to sell it for 1/3 its value. Unless some kind of an inside or family deal or whatever. Could easily be sold for much more. I'm suggesting caution. I was royally burned on my very first build with a 306 I bought off eBay. It was completely misrepresented by the seller and cost me several thousand to fix. I found out much too late for any recovery from the seller, who by then had been delisted by eBay. No surprise. BTW, a 347 is an ideal engine for these builds. Nice power in a compact size.

https://hosting.photobucket.com/albums/ab234/edwardb123/Factory%20Five%20Mark%204%20Roadster%20Build/Engine/.highres/IMG_2125_zps2a587ff4.jpg?width=960&height=720&fit=bounds (https://hosting.photobucket.com/albums/ab234/edwardb123/Factory%20Five%20Mark%204%20Roadster%20Build/Engine/.highres/IMG_2125_zps2a587ff4.jpg?width=960&height=720&fit=bounds)

I can’t get over how great everyone has been on this forum. Yes, I’ve confirmed not a ford boss engine. It’s a 2 bolt main. He bought it from a guy going thru a divorce and now is going in a different direction with his project. Which is why the block has parts added and taken off to confirm what he thought he had and take photos. I told him I’m still interested but wanted more photos of all the parts. He said it has the parts listed and I want to see proof. Still could be a motor to build out with the right heads and intake. I originally asked a builder whom I need to call to price out a 302 with 300 to 350 horse and ordered my MK4 with a fuel pump for EFI. I was planning on installing a Holley Sniper. My guess a Roller 302 bored .30 over short block would still be worth $2500 to $3000. Is that correct? Thanks again. The saga continues. David.

[Jeff Kleiner]

…My guess a Roller 302 bored .30 over short block would still be worth $2500 to $3000. Is that correct? Thanks again. The saga continues. David.

Depends on what’s in it; hyper or forged, rods and bolts, etc. but if it’s just built back to 5.0 HO specs that’s high.

Jeff

[dherrenbruck]

Just received more photos. All I can research is the stamping on the oil pick up is for a ford 302. The other standings (0109 on the crank doesn’t come up anywhere). The other stampings are in the block. Any help most appreciated. David.

[Jeff Kleiner]

See if you can get photos of the bottom of the cylinders from the crankcase. Also have him turn the engine until one of the cylinders is at bottom dead center and then take a photo showing the measurement from the top of the piston to the block deck. If the bottom of the cylinders are relieved for connecting rod clearance and the measurement is 3.4" you'll at least know that it's a 347 (or 342 if it isn't overbored).

Jeff

[Gordon Levy]

A4 Block if it has 4 bolt mains

[J R Jones]

347ci is a displacement that could be applied to any SBF:
4.030 squared, times 0.7854 X 3.4 X 8 = 346.9 I corrected my earlier equation that was (wrongly) circumference based not area. Sorry.
We raced 289 K blocks with two bolt mains (Cobra and GT350) enlarged to 302 by stroke and had no block structure problems.
In the late sixties Ford released the Boss 302, (four bolt mains) described in this thread. We had no structural problem with those either.
A 347 stroke crank/rods will not clear the cylinder skirts without relief.

I have a buddy that built a 1995 Ford Thunderbird Super Coupe track day car with a modified SBF.
Without details I assume he was short of the 380-400 hp we raced, likely 325-350hp.
I crewed his first event at Road America.
After a couple of sessions the T-bird was towed from turn five, below the downhill straight, to the paddock. The block was split longitudinally from the distributor aft through the lifter galley/cam journals.
Otto admits, he started with a low performance 302 salvage block.
jim

[dherrenbruck]

Well, I finally broke down and drove 1 1/2 hours to see this great deal and determined it appeared to be a stoker based on measuring everything and noting the butcher job some shade tree mechanic applied to the cylinder walls for clearance. However, it was not new as I was led to believe. Clearly used. Enough said. But being retired one of the benefits is having time to waste chasing down deals.

Just wanted to thank everyone for taking the time to help. You all were great. David.

[R. Button]

Just a short note on the 347 engine - if you get an engine built for 0 balance you will need to be aware that getting a clutch and damper set for 0 balance will take a bit more work!!
My engine is a 347 and I worked with the machine shop to setup all rotating assemblies to 0 balance! Then a few miles, (thousands of) later, I needed to replace the clutch and with it the pressure plate. Took weeks of calls and meeting with machine shops to get the balancing done.

[Ford & Jeep Fan]

Will be hard to absolutely confirm without measuring bore and stroke. ..............


stroke is easy to measure with a spark plug removed and long piece of wire. crank engine over to TDC , then crank to BDC. with a wrench and measure the piston movement . (3.0 is a 302)----(3.4 is a 347(.

[Olli]

Another word of caution in a situation such as this. Buying an engine from an individual can become problematic when you go to DMV for inspection and titling giving the lack of a proper invoice. What if the engine turns out to have been stolen?