Ford Muscle Forums : Ford Muscle Cars Tech Forum

Ford Muscle Forums : Ford Muscle Cars Tech Forum (https://www.fordmuscleforums.com/forumindex.php)
-   Stroker Engines (https://www.fordmuscleforums.com/stroker-engines/)
-   -   347 Stroker Pistons (https://www.fordmuscleforums.com/stroker-engines/593306-347-stroker-pistons.html)

jonnys 01-04-2015 01:22 PM

347 Stroker Pistons
 
1 Attachment(s)
This question must being asked so many times, I'm building 347 stroker with 80 roller block for my little 289 65 mustang sleeper over in the UK.
I'm using scat crank and Scat I beam rods.
I'm going to buy Afr heads not sure which ones yet and which cam too, but what I'm really keen to learn What pistons you like and have experience with and do all of them have the bottom rail braking into gudgeon pin.
Thank you in advance I know this must being asked many times.
Jon.

PSIG 01-04-2015 02:19 PM

Re: 347 Stroker Pistons
 
Assuming you're using the longer 5.4" rod, intersecting pins and ring grooves are common in the 347. Not all have them, but there are 'fixes' that solve the issue. For those that do intersect, the issue is solved with lower ring spacers that provide ring support, or pin-hole inserts that do the same thing (fill the open gap). Others cram the rings closer together, but then can have issues with ring flutter at high rpm, and top-ring overheating. If you prefere a certain fix, then your choices of material and head volume are also restricted. The bottom-line, is that 5.4" rod 347 pistons usually have intersections, but they are not a problem, and choosing the best form/CC/shape is generally a higher consideration. My 2.

David

falconfred 01-04-2015 02:38 PM

Re: 347 Stroker Pistons
 
I like the Probe SRS forged pistons which are made for a 5.315" long rod. This eliminates the oil ring problem (if it is a problem) that PSIG mentioned. The downside is that they result in a little more rod angularity than a 5.4" rod.

jonnys 01-04-2015 02:44 PM

Re: 347 Stroker Pistons
 
1 Attachment(s)
I should have said it's 5.4 rod length with 3.4 stroke crank, that I have.
Thank you for replies, very interesting.

PSIG 01-04-2015 03:08 PM

Re: 347 Stroker Pistons
 
Quote:

Originally Posted by falconfred (Post 2286538)
I like the Probe SRS forged pistons which are made for a 5.315" long rod. This eliminates the oil ring problem (if it is a problem) that PSIG mentioned. The downside is that they result in a little more rod angularity than a 5.4" rod.

Tue that. However, for those not wanting to deal with the pin issue at all, it's a viable choice. The rod ratio only changes by 0.02, which is a non-issue for 99.5% of engines out there, especially for street where stroker rod ratios often dip to the low 1.40's. Even at those low ratios, there are plenty of 100,000 to 250,000 mile engines running out there.

Don't let short ratios or pin gaps bother you. Just look at the zillions of Honda 1.6L engines out there with 300,000+ miles and a shorter rod/stroke ratio. Or the famous Chev 454 or 400. One side-note for street engines though, is that the shorter rod increases angle, but it also allows a longer piston skirt to stabilize in the bore. The longer skirt more than makes-up for the increased angle and side-load in a street engine. Hypereutectic pistons with their close bore fit also favor better stability with lower wear and reduced rocking to increase ring seal and reduce skirt cracking. Still, will you actually drive it enough to ever wear it out? Really? They all work so take your pick and have fun.
http://i.imgur.com/m5M95.gif
David

barnett468 01-04-2015 05:00 PM

Re: 347 Stroker Pistons
 
ok, with a 5.4 rod, the pin will be in the lower ring land and your engine will likely smoke/burn a little oil.

if you tell us what your goals and budget are we can help you spend you money . . there are several of us here that know a s__t load about making hp and not breaking the bank to do it and i think most of us know 347 strokers very well.

the most common piston for them is the probes but ford uses mahles in theirs . . ones with the most piston skirt are the best for most apps.

you can make stupid hp with afr 185's

if you do not have a crank yet and plan on much more than 400 hp, i would run an internally balanced one . . K-1 is a nice crank and costs less than the eagle might make one also.

you may need to run special bearings that are slightly narrower or beveled to have clearance on large crank journal radiuses but they are easy to find . . the clevite h nearing is common.

if your block is not machined yet, i would have it milled so the pistons are around .003" below the surface . . this will reduce the potential for detonation.

i see you are from the uk . . i am on the site there also but few people there know much even though they pretend they do.

do you want a mild, moderate or dragster type idle?

freeway flier, lite to lite drag car or inbetween?

are you open to different rear gears?

tire roaster or tire warmer?
.

frdnut 01-04-2015 06:31 PM

Re: 347 Stroker Pistons
 
Quote:

Originally Posted by barnett468 (Post 2286674)
ok, with a 5.4 rod, the pin will be in the lower ring land and your engine will likely smoke/burn a little oil.


.

It's a shame this internet bulls**t just won't go away. My 408 piston has the same setup and it does not smoke or burn oil...It does smoke and burn the rear tires though. :D

barnett468 01-04-2015 06:59 PM

Re: 347 Stroker Pistons
 
Quote:

Originally Posted by frdnut (Post 2286746)
It's a shame this internet bulls**t just won't go away. My 408 piston has the same setup and it does not smoke or burn oil...It does smoke and burn the rear tires though. :D

it won't go away because it is my first hand personal experience . . i have seen it on MANY 347's in the last 16 years or so, including ford crate 347's before the discontinued them years ago . . your experience is obviously different and apparently more limited.

jonnys 01-06-2015 11:24 AM

Re: 347 Stroker Pistons
 
1 Attachment(s)
Hi,
I have bought scat stroker crank 28 oz balance, scat I beam rods, steel flywheel and damper already, and I have donor 80 roller block that will be machined 30 thou over in bores and decked honed and all squared up and true.
I Will block dip stick hole and use existing front water pump etc so looks stock, I will even spray the afr heads black, I was think 185 or 195 again was going to see what results others have had.
Pistons was even considering JE just because had good results on motorbike with them compared to wiseco, but tuning bikes comes natural as have lots experience but cars not really done much so on big learning curve and advice gaining here is greatly appreciated.
I'm beginning to think I should done 331 kit but too late for that now.
Budget was not great but not rushing anymore just doing it in stages so budget not too much of issue as long as don't go crazy.

jonnys 01-06-2015 11:31 AM

Re: 347 Stroker Pistons
 
1 Attachment(s)
Reliability is defiantly priority, as daily driver in summer, so would like decent tick over as well as occasional strip and circuit track day use.
Sounds like I want my cake and eat it but do not want to destroy it as a daily driver, I have done loads to it over last 10 years and drives so so well, almost like a modern car, only sign its messed with is its very low, more power is last job.

barnett468 01-06-2015 02:19 PM

Re: 347 Stroker Pistons
 
.
the 185 afr's will make a lot of hp and are what i would use unless you want monster hp . . get the stiffer springs and 7/16" studs if you run high spring pressures or over 6500 rpm.


here's one good middle of the road cam.

http://www.compcams.com/Company/CC/c...csid=1057&sb=0


i would mill the block so the pistons are around .003" below the deck . . this will also square the deck to the crank if they do it right

you can also have it bored and honed with torque plates . . if you plan on using more torque than stock on the head bolts, this might be a good idea and have the plates torqued to the spec you will use.


the quality of the rings is important, i would use plasma moly with a barrel shape.

je std pro seal, barrel face top ring plasma moly inlay?, tapered second, file fit

http://www.summitracing.com/parts/je...0305/overview/


je premium pro seal barrel face top ring plasma moly coated, reverse twist tapered second ring, file fit, $114.00

https://sdparts.com/details/je-pistons/jej100s8-4030-5


the most common piston materials are 2618 and 4032 . . the 4032 is high silicon content which is low expansion material so you can run tight piston clearances which is my preference, especially in something that has a short skirt.


je srp, 1.1 compression height, 5cc volume, 423 grams, .927 pin od, .030” p/n - 140689-8 . . this uses the close ring spacing psig mentioned to keep the pin from being in the lower ring land . . this will be around .006” below the deck on your block if it is unmilled . . you need to verify your pin diameter on your rods . . pin intersects oil ring . . .

http://www.summitracing.com/parts/sr...view/make/ford


mahle power pak pistons forged 4032 aluminum, 395? grams, pin 118 grams, .927 pin . . file fit rings model unknown, they make 3 types . . $792.00

http://www.summitracing.com/parts/ml...view/make/ford


same mahle kit as above only $557.00

http://www.ebay.com/itm/Mahle-SBF090...#ht_2890wt_938


pre fit rings

http://www.summitracing.com/parts/pc...-030/overview/


probe 1.090 ch, 2618 aluminum, .912 pin

http://www.summitracing.com/parts/pb...view/make/ford

. . . . http://static.summitracing.com/globa....jpg?rep=False

.

.

barnett468 01-06-2015 07:24 PM

Re: 347 Stroker Pistons
 
.
Quote:

Originally Posted by frdnut (Post 2286746)
It's a shame this internet bulls**t just won't go away. My 408 piston has the same setup and it does not smoke or burn oil...It does smoke and burn the rear tires though. :D

From the ford muscle forums tech section.

"On 347 pistons the pin intersects the groove, resulting in increased oil consumption."

How to Build a Ford 331 Stroker. 347 Stroker. - FordMuscle
.

jonnys 01-07-2015 11:52 AM

Re: 347 Stroker Pistons
 
1 Attachment(s)
Thank you for all information I will have good read through all this.
I can only read to page 2 on that article What do I need to do to read more
Jon.

PSIG 01-07-2015 12:20 PM

Re: 347 Stroker Pistons
 
As described in my first post, there are now solutions for unsupported oil rings from most piston manufacturers. That article was written back before most piston companies started using the supports, and yes, some would burn a bit of oil with the ring flexing. Since then with the movement into the "stroker age", lots has changed. With the various oil ring supports, that issue is cured, and the alternatives of short rods, packed rings, or staying with a 331 are also no longer necessary. This is one of those cases where builders found the solution, by making wrist pin 'buttons' slotted for the oil ring, and the piston companies picked-up on it. Other companies developed other systems, like ring support rings, to get around Company A's patented solution. ...And the world is a better place.
:D
David

barnett468 01-07-2015 12:30 PM

Re: 347 Stroker Pistons
 
Quote:

Originally Posted by jonnys (Post 2288802)
Thank you for all information I will have good read through all this.
I can only read to page 2 on that article What do I need to do to read more
Jon.

i'm not sure i understand your question . . if you have questions on your build or want suggestions you can simply ask . . lots of people here know lots of things.

the engines i have seen smoke had lower ring supports but no buttons . . i have actually never seen a piston with a pin that intersected the oil ting groove without an oil ring support . . the ford engines that smoked and had piston knock all had oil ring supports . . our shop was a dealer and we sold many of their crate engines and got tired of having to return them.


All times are GMT -7. The time now is 05:58 PM.

Powered by vBulletin® Copyright ©2000 - 2019, vBulletin Solutions, Inc.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.

 
For the best viewing experience please update your browser to Google Chrome