[crashecobra]

I am in the process of tearing down my 302 FI and am going to have to rebuild it. My question is, what are the advantages to a stroked motor (347) over others. And what are the disadvantages?!
How bad will the gas mileage be, if I can keep my foot out of it?
I know I can get a short block fairly cheap, but my cousin is a professional mechanic and if not charging me much to do this. (Can you say FREE!) So labor cost is no concern.

Many Thanks,

Earl Gordon

 

[RoadRebel]

welp,

Unless you like tearing a motor apart on a regular basis (10k miles) I would avoid the 5.4 rod 347 engine. They rifle barrel the bores in a short time due to the poor rod ratio. The rifle barreling basically is from the pistons rocking in the bore allowing the skirts to wear the finish hone etc off the cylinder walls at the intake and exhaust of the bore.

The 331 and many other varients are much better for this condition. And yes, they are good for a significant gain in hp and torque. If your crank etc is trashed, If say go for it.

Phil

 

[crashecobra]

So a 331 kit is fairly dependable? That is what I was afraid of on a 347 stroker. I will be driving my car very often.
And yes my crank is shot.

Thanks,

Earl

 

[MJN]

Earl

After a lot of research I decided to go with a 331 on my rebuild. I didn't use the 5.4" rods but went with a 5.314" rod from Coast High Performance along with matched Probe pistons and a Scat crank. The 347 set ups do put a lot more side load on the cylinder walls but some better engineered pistons offset the pin bore a little more to counteract this. The main reason I went with the 331 was because of the piston ring pack placement. I definitely didn't want the oil ring in the pin but I wanted the ring pack to be lower than normal for my supercharged set-up. the only way I could do this was with the 331 and the slightly shorter rod.

I don't have a lot of miles on my engine yet but I am very pleased with the combination. You will notice a real difference over a 302.

 

[Roscoe]

Good article on stroking engines

http://www.ralphsmachine.com/stroke_length1.ivnu

Roscoe

 

[crashecobra]

Roscoe, that is a good article, Thanks.
Mike you make a good point about the stroker kits. I am still trying to decide which way to go.

Earl

 

[RoadRebel]

The 347 with the redesigns piston pin geometry still suck, Im running one in my blown motor and have to re-ring it allready. 5.4 rod is not recommended for you guys unless you like to rebuild all the time..SO,if you not going to squeeze every once out of it stick with.

Phil

 

[Richard Calhoun]

Is there anybody out there with more than 10,000 miles on there 347's. I have about 1 mile on mine and it still runs great.

Dick

 

[ToyoKogyo12aTurbo]

I stroke it to the east
And I stroke it to the west
And I stroke it to the woman that I love the best
I be strokin´

 

[crashecobra]

What about the 331 stroker kits, anyone running them with good results? I just don't want to have the problems such as what Phil is talking about.

Earl

 

[Roscoe]

Crash,
If you are going to stroke why not look for a good bargain on a 351 block? You can do a mild, dependable stroke to 392.

Roscoe

 

[crashecobra]

I've thought about that, but am still leaning towards the 302 block. I may do this, then as a project for next winter build a 351 stroker. It's just that I already have most of the parts for the 302.

Thanks Roscoe,

Earl

 

[Travis G]

I really like my 331, but I still have under 6k on the motor. Went through the same stories on the 347 rod ratio. I don't think it's as common a problem as what the internet makes it out to be, but I never heard of oil consumption problems on a 331.

edit: Oh, gas mileage. I get 12.5 mpg with my foot in it all the time!

[ December 30, 2002, 08:27 PM: Message edited by: Travis G ]

 

[boondoggle]

Crash:

If your sticking to little is better? Go with the 331; you need decent rod geometry to spin the little beast.
Mileage will be roughly the same; assuming, you keep your foot out of it. Remember mileage is horsepower per hour extracted. However, if you ever do boot it you have to feed an extra 30 CI's.

gn

 

[boondoggle]

Crash:
I forgot the main point.
a straight 5L can be make to rev higher and make just as much HP. a stroker would'nt rev as much but will make much more torque. This kind of reduced down to your intended use. Screaming around a track at max vel; go with a hot 305. If street cruising and bursts of acceleration is the use; then that is right is the wheelhouse of a stroker.

gn

 

[Quinta2]

I've got about 4000 miles on my Coast High Performance 347. Most of those 4000 are on the race track at 4-6k rpm. It has been flawless, and uses very little oil. The guys at CHP/Probe really understand stroking, and use them in their own vehicles. Next week I receive my 351W stroked by Probe to 427, so I guess I'm a believer.

 

[crashecobra]

It sounds like a 331 is the way to go. Your right boondoggle, the on road power is why I want a stroker. Plus since I have to rebuild, I figure why not do it now and have a few extra ponies under the hood. I can always put a supercharger on it later!

Travis, What kind of horsepower are you making with you 331?

Sagebrush Bob A 427 stroker Talk about torke!!

Thanks again everyone,

Earl

 

[kbconv]

I wouldn't be afraid of a N/A 347 if it was built right. Get in line and call Ed Curtis if you are serious about a really good one, check the Corral for several that last long in heavier Stangs. What are Gordon's thoughts on them? I just found this site. Look at the rod ratio's on the new 4.6's and 5.4's and the "great" engines of the past, I think they are near a 347 with a 5.400 rod. I'd be a little leary on a blown one just because, ha!

I was thinking of going with a turbo 331 for my 95 Stang vert "tank", but am just gonna go with the FFR, been watching them for 3-4 years now, the MK II $1000 deal sealed it.

Now I've got a virgin used A-351 SVO block also I bought recently to think about too. May still may try a N/A 408 or 393 in the FFR, gonna try to fit a Roush 3 piece intake on it, that may knock some low end off of it. If I go 302 block base I will do a 347. Trying to decide between balance and power, don't just want a tire smoker.

John

 

[Cobra3657]

Well, now I've got another thing to sweat over. My 347 should be finished in a week or so. The crank is already bought and installed. I've never heard about all these problems with stroked Ford 302s. My builder has built a couple other engines for me in the past, and they've always been rock solid.

It'll be a N/A 347 with Holley's SysteMax II kit. I don't know all the details yet about the internal components, but I did catch a glimpse of the aluminum pistons and forged steel H-beam rods he's putting in it. Should have plenty of power for the street and occasional race.

I don't have any plans to ever add a supercharger. Will the aluminum pistons help to prevent the "rifle barrelling"? I don't know if they have the offset pins or not.

 

[Matt M]

I got 4000 or more on my 342 CCM stroker. Runs like a mofo, 20 mpg on cruise and no filings on the magnet (after break in). So there.