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Discussion Starter #1
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.
 

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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
 

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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.
 

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Discussion Starter #4
I should have said it's 5.4 rod length with 3.4 stroke crank, that I have.
Thank you for replies, very interesting.
 

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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.

David
 

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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?
.
 

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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.


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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
 

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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.
 

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Discussion Starter #9
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.
 

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Discussion Starter #10
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.
 

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.
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/cam-specs/Details.aspx?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/jep-s100s8-40305/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/srp-140689-8/overview/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/mle-sbf090030f06/overview/make/ford


same mahle kit as above only $557.00

http://www.ebay.com/itm/Mahle-SBF090030F06-4-030-Bore-Powerpak-FlatTop-Pistons-w-Rings-for-SB-Ford-/301261858986#ht_2890wt_938


pre fit rings

http://www.summitracing.com/parts/pcr-41858cp-030/overview/


probe 1.090 ch, 2618 aluminum, .912 pin

http://www.summitracing.com/parts/pbp-10660-030/overview/make/ford

. . . .


.

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Discussion Starter #13
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.
 

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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
 

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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.
 

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Discussion Starter #16 (Edited)
Just realized need subscription to see rest of the article that is what i meant.

I did not know about torque plates good tip there indeed.

What pistons use buttons for the ring support.

Daft question why do they do two different diameter rod ends.

Jon
 

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I did not know about torque plates good tip there indeed.
its really a little bit anal to do that but i like to do it on some apps especially strokers like this and especially if i am using low expansion pistons and even more so if i am using higher torque on the head bolts than stock . . it only costs me around $45.00 more to get it done this why so its also pretty cheap . . i also run most of my engines at 180 or 185 as opposed to 192 for several reasons.


What pistons use buttons for the ring support.
i don't know nowadays, perhaps psig would, but again, good rings will be a good defense against oil burning . . also having someone that knows what they are doing when boring and honing . . some shops accept a bore that might be tapered by .0005" or more when they are done . . others shops will fix this on a fancy power hone machine.


Daft question why do they do two different diameter rod ends.

Jon
xlnt question, lol.


i also saw you mention motorcycles . . i was in charge of the r and d department for a very big motorcycle mfg for several years and did a bit if racing myself so i am familiar with weisco pistons..
 

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Barnett pretty much covered it all, but here's my extra penny of thoughts. The two pin diameters are Ford (.912) and Chevy (.927). The reason is that half of every set of SBC pistons are identical to SBF pistons, due to where the valve notches are. Being able to use a Chevy piston greatly increases your choice of off-the-shelf pistons, and/or allows machinery set-up for them to be used for Fords as-well. Same with the rods. So they make both rods and pistons with both pin sizes to allow this swapping. They also make them all with circlip grooves, so they can either use circlips (floating pin) or press-fit pins, depending on the rod type.

While not as common today, it was often the only choice early-on to resize (pressed pin) or "bush" (floating pin) the rod end to take a Chevy piston that would work best. 30 years ago, SBC stuff was everywhere and sometimes the only choice, much more than today. Mopar pistons had huge wrist pins (.984) and the rod end would get too thin when re-bushing, so they were rarely used unless Mopar rods were also used in certain Ford strokers.

Torque plates and block heating are to allow machining under 'running' conditions. Since the head bolts and head clamping pressure distort the bore slightly when torqued, and a warm engine also changes shape slightly, using torque plates with block heating will give a finished bore that is perfectly round when running. Otherwise, the bore is only perfect when cold if machined that way, and never perfectly round after the bolts are torqued.

This is one reason performance engines can have a very low leak-down (blow-by) compared to a Mom & Pop engine. It's all in the details. I'm one of the anal types, and always use torque plates and heating if the engine is for true performance, racing, or me. If it's just a cruiser that has a lumpy cam and wears a stroker badge for status (typical street car) - whatever. I agree with Barnett that they all run OK in Mom & Pop mode, make plenty of power for that, and do the job fine.

David
 

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Discussion Starter #19 (Edited)
Can I ask what you mean by block heating.

All good advice thank you.

Im not interested in pub talk this car is really sleeper I have tried to hide all the mods just trying to build best road car that i can that is good fun and can be used on circuit couple of times a year when I feel like it.

My main bike is old gsxr 1100 which is so special with so much hand made trick stuff and one off parts i have made and done some quite radical stuff. Its making 171 hp 98 ftlbs at back wheel normal aspirated on pump gas its real animal got some good lap times out of it. Hurt myself couple years ago lost little interest in it and being messing with it for so long cant get motivated with it, probably be back when sun comes out again.

One final thing the torque plates what do they look like for fitting and do you machine block to fit them.
Ill shut up now ha ha.

Jon
 

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All good advice thank you.

My main bike is old gsxr 1100 which is so special with so much hand made trick stuff and one off parts i have made and done some quite radical stuff. Its making 171 hp 98 ftlbs at back wheel normal aspirated on pump gas its real animal got some good lap times out of it.

Can I ask what you mean by block heating.

One final thing the torque plates what do they look like for fitting and do you machine block to fit them. Ill shut up now ha ha.

Jon
yeah, some guys here like psig can bring the tech . . you won;t go wring with the advice you get here as you might from somewhere else . . i bet you never even saw the word torque plate in any of the other posts or magazines you read yet it is not an unusually super special, expensive techno thing . . this is just one example if how incomplete a lot of the forums and magazines are.

Typical engine build article.

"Buy trick flow heads and a big a_s roller cam and don't even ask what rings come with the stroker kit [because all rings are the same] and it will hail a-s . . and by all means, do not check the balance or crank and rod sizes because they always come properly sized from the country that can't even build a rocket that will stay in the air for more than an hour, if that long." . . yeah ok, lol.


block heating is just as it sounds . . they heat the block close to typical operating temp before they bore it, but this is typically done in conjunction with torque plates . . in other words, use the torque plates if you are anal . . add heating of the block with the torque plates if you are super duper anal . . nothing wrong with being anal if you can afford it, but you might be spending money that is really unnecessary in some instances . . as far as being anal about the block, imo, the more perfect the bore is under actual driving conditions, the longer it will last . . it will often have an increase in power too but for street apps the amount is irrelevant and nearly negligible but it might make you can sleep better at night.

if a shop does not have torque plates, i might be hesitant to use them . . that being said, it might be unusual for them to have torque plates for american cars over there . . it is just around a flat 2" thick plate with holes that are bigger than the bore and they bolt it down to spec just like the cylinder head.

yeah the suzi 1100 will get with the program even in stock mode and with your hp boost it will be pretty nasty, especially if it is one of the early models . . they were around 75 lbs lighter than the later ones . . i worked for the "ninja" company, lol.

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