Stroker Kit Info

[AnthonyR23]

Hi, I did a previous post regarding what stroker kit to get... and was told to get a certain 347 kit... with certain rod length.. anyways is there anyone who are against these kits... or who would recommend not going to 347... eg. maybe smaller for longevity??

 

[Funanin]

definitly YES. DO NOT BUILD A 347!!! I talked to the guys at my machine shop and they said that the way that motor works (rod length, crank design) is just BAD and very unbalanced for a 302 block. I would go 331 if u want to do stroker because look at the lightings! They have 331 from the factory, and they are fast as ****!

 

[Grn92LX]

Funanin is EXTREMELY WRONG! I can not believe garbage like that is allowed to be posted on these forums! Where are the moderators?!!!??!

Go 347, get which ever kit you like, probe, scat, eagle. Im running a scat crank, probe 5.315" rod (prefer the 5.4") and probe pistons. Works awesome for OVER 2 and a 1/2 years now

 

[PUNISHER RACING]

:Zip2: :Zip2: :Zip2: who let him on here!

there is nothing wrong with 347's the only thing ever said bad about them was in through pin oiling. that is corrected with a 5.3 rod version and is not bad in the first place. the only thing i will say is a 331 makes its power a little lower and does not need to be zinged like a 347, but hey i have one so how bad are they!
the 347 is a very strong, reliable engine so do not let fools scare you off!


and another thing the lightning is a mod motor , not a pushrod 302 blocked engine ya' &^%^$*%* !

 

[AnthonyR23]

I'm really glad I asked this question.. because it definitely would make for a good debate... I'm sure there are guys out there who work at machine shops that are against doing the 347 strokers ... I kinda would like to hear more of the debate... do these engines only last for a short time... why woundn't ever rebuild be a 347?? If they were so good.. I am very tempted to go that route.. but want to make a more informed decision.... it sounds good to me.. has anyone had bad personal experiences with a 347??

 

[347HO]

A 347ci will flat out make more power and perform better than a 331ci or 306ci sbf when done correctly. This is to assume rpm for all three are the same.

Rod length for 347ci kits are for those who do or don't want the "oiling" ring in the piston pin. WHEN done correctly it does not matter which rod you use.

Rod ratio is a MYTH. If you don't believe me... then research the "longevity" of the infamous 454ci BBC. There are other Boards out there whom have addressed this subject and have extensive posts WITH facts to disprove the 331ci will outperform/outlast the 347ci sbf.
Any "shop" which tells you not to build a 347 because of rod ratio and longevity is a shop I would not do business with... for the reason they do not have the knowledge or the means to "build" not just "assemble" a performance engine.

To answer the other part of your question;
Rod lengths are 3.315" and 3.40" and the difference will be made up on the compression height of the piston.

The question you ask and the questions which will arise are "deep" and I really don't want to re-type or re-post what is already available. If you want a link and references to factual data PM me... I'll be happy to send you the URLs.
If this explodes into a serious debate, I'd be willing to continue posting up my beliefs and the facts which back them up, and supportive posts and people who are willing to assist.

 

[AnthonyR23]

ya I read a lot about the pin oiling, oil consumption, etc. and how the shorter rod fixes that... what do you mean about that the 331 doesn't need to be zinged??

 

[PUNISHER RACING]

from experiences i had in the past with both engines the 347 seems to like rpm's a bit more than the 331 thats all i meant by that!

 

[AnthonyR23]

ok.. I am going to dissassemble my engine myself... and am going to try to do as much as I can.. I guess... I might aswell have the machine shop do the bottom end.. any ideas of how much this would cost... not including the parts.. just labor.. $500 ???

 

[AnthonyR23]

I will also upload some pics.. for those of u that may be interested.. I am buying a engine stand and puller from canadian tire... its 40% off this week.. and I'm pulling the engine and tranny this weekend...

 

[347HO]

In my area, I spent 1000.00 just on cleaning, machine work and balancing.
That price was for everything done correctly, and to my tolerances.
I'm unfamiliar with your location... here we pay around 35.00 to 45.00 dollars per hour = labor rate. Is that comparable to your area?

 

[5spd GT]

There is some bad information in this topic. Even some coming from those saying there is bad information

Listen here...

First, I want to here why a 5.4" rod is preferred

Do the 5.315"/1.175" combination.

- There is NO oil ring intersecting into the ringland. This allows heat to penetrate into the oil ringland area. Heat chases away oil. You want oil in the piston pin boss.

- A shorter rod is also good for boosted and nitrous applications.

- There is more piston material on the 1.175" pistons.

- The only positive I see on the 5.4" rod is that it is a very slight difference in grams of weight.

Here is the deal with building a piston/rod combination where there will be little to no oil consumption issues. It depends on the builder. 99% of the engine builders (namely, local and some "professional") do not use proper piston to wall clearance, oil support ring land type and position, appropriately.

You cannot possibly say that you will have no problems with the 347 with the oil ring intersecting the wrist pin area.

Mark O'Neal from Coash High (Probe) and Barry R from Survival Motorsports are extremely knowledgeable and are in this very field being discussed. You want to know what they recommend for the street?

That is right, the 1.175"/5.315" combination

A Ford Lightning utilizes a completely different bore and stroke combination:

3.55 (bore) x 4.16 (stroke).

A SBF 302 uses a 4.00"/3.25" combination.

There is a big REASON why 99% of rods and pistons do not intersect in the automotive industry.

Now, for the rod ratio not being a factor. Sure, I agree with that. 99% of us do not need to worry about it for our purposes. However, Nascar uses a 1.93:1 rod ratio for a reason.

Some claim it is simply the by-product of the stroke and rod used. Nascar did testing and shortened the piston as much as possible to lighten it and utilize a longer rod. This gives a better rod ratio, aka, less frictional losses. Someone needs to pick up a book from John Heywood

In a world of extracting every last HP and engine longevity at 9-9500 RPM for 500 miles, they think of EVERYTHING. Thinking of everything is what determines the difference between #1 and #2. 2 HP can make or break a race over 500 miles. 2 HP just happened to be what the GM engines (358 CI) noticed from switching from a 5.250" rod to a 6.1" rod. Extreme example? Maybe, but there is truth. The Pro Stock guys are using 1.71:1 ratios.

Do not take this to an extreme. Rod ratio is typically highly exaggerated to most people. However, a good solid idea that I see in the professional world is a higher rod ratio as the RPMs increase.

Some may argue, well look at some of the foreign vehicles like Honda. Running 1.5:1 (similar) rod ratios, but look at their bore size. Very small.

The rings take the brunt of the wear. I actually have a formula to figure out the differences in side-thrust.

I often wonder why many credited engine builders want a thicker outside wall, than inside

You will see, per capita, higher rod ratios last longer than short rod ratios.

But, this is not something that any of us guys in here need to worry about.

If you want to read more about strokers, check out the link in my signature.

 

[AnthonyR23]

thanks again 5sp gt, I really appreciate it... I am def. going to go with what you recommend if I go with the 347 stroker kit.. just wanted to get some more opinions... your posts are def. the most informative though... so thanks for that.. Not that I don't trust what you were saying just wanted to get more info.. but I guess there is only so much I can get... for longevity... is the 347 stroker a bad idea?? or not at all??

 

[5spd GT]

The 347 is going to be fine. There is no definitive mileage that they will give up at, nor is there a definitive mileage that the 302s will give up at.

They both can last a very long time if built properly

 

[giddyup306]

Here is the deal with building a piston/rod combination where there will be little to no oil consumption issues. It depends on the builder. 99% of the engine builders (namely, local and some "professional") do not use proper piston to wall clearance, oil support ring land type and position, appropriately.

I agree with this statement 100%. I used to build engines for a living. The company I worked for had a 30 month warranty on their 347 strokers. How can they warranty them if they are such a "poor" engine. FWIW the components they used for most of their stroker motors are the same things that people here on Stangnet use in their own personal builds. Eagle, Scat, CHP etc. And just in case you're wondering about warranty claims less than 2% of the companies PROFIT went towards warranty.

 

[irish]

While some may not agree nowadays it is not a bad idea to simply buy a stroker shortblock from somewhere like Fordstrokers.com or CHP. They are less than 2000. You do the math, 1000 dollars of machining/cleaning and assembling, plus you need to buy a decent kit. My next motor will be this way, and I'll sell off my old stuff to get a little money back.

my 2 cents

By the way there was a ton of just plain wrong info earlier, do not build your motor based on what strangers on the internet tell you. Call a shop with a good rep like the ones I mentioned earlier that builds these motors everyday and listen to what they say. If you are in a stock block you do not need a forged crank.

Matt

 

[347HO]

First, I want to here why a 5.4" rod is preferred
QUOTE]

I don't think the 5.4" rodded 347 is preferred... but probably because that's the rod you had to use in the past.

- There is NO oil ring intersecting into the ringland. This allows heat to penetrate into the oil ringland area. Heat chases away oil. You want oil in the piston pin boss.

When done correctly, this is not an issue. If you have restricted oil to the piston pins... there are other issues.
Ring gap and lands are the critical detail to ensure is correct when doing a 5.4" rodded 347.

- A shorter rod is also good for boosted and nitrous applications.

Explain this... because boosted and bottled applications don't require much but a nicely matched camshaft.

- There is more piston material on the 1.175" pistons.

Why does this matter? All I see is a heavier piston... although I'm not promoting the 5.4" rodded 347 sbf. I actually have the Probe 3.315" rodded ProStreet version.

You cannot possibly say that you will have no problems with the 347 with the oil ring intersecting the wrist pin area.

Mark O'Neal from Coash High (Probe) and Barry R from Survival Motorsports are extremely knowledgeable and are in this very field being discussed. You want to know what they recommend for the street?

That is right, the 1.175"/5.315" combination

If I built the 3.4" rodded 347ci sbf... I can assure you I will not have oiling nor longevity issues.

Probe is one of the premier 3.315"/1.175" 347ci sbf rotating assembly manufacturers, and should PROMOTE their product as such.

Yes, the smaller rodded setup IS nice... my choice because it's my first 3.315" rodded 347. Will it perform better than the other... probably not.
My opinion as well as many, many others; the shorter rodded setup is easier for the novice or beginner builder/assembler as there are more details that can be "overlooked" and still perform well.

I'm not disagreeing with 5spd, I just see things from a different angle and experience.

 

[5spd GT]

While some may not agree nowadays it is not a bad idea to simply buy a stroker shortblock from somewhere like Fordstrokers.com or CHP. They are less than 2000. You do the math, 1000 dollars of machining/cleaning and assembling, plus you need to buy a decent kit. My next motor will be this way, and I'll sell off my old stuff to get a little money back.

my 2 cents

By the way there was a ton of just plain wrong info earlier, do not build your motor based on what strangers on the internet tell you. Call a shop with a good rep like the ones I mentioned earlier that builds these motors everyday and listen to what they say. If you are in a stock block you do not need a forged crank.

Matt

Jim @ Ford Strokers got banned from this site. Up until a year ago, he believed a 331 was better than a 347. He speaks badly of the people on this site. There is no need to support that cause.

It is a pet peeve of mine to see people get money when they handle themselves very unprofessionally. CHP is good

Personally, I would go with RNH Performance. Rick does a great job and he post on this site with lots of useful information. He has probably one of the top $/Quality ratios there is. As he says, he can build you something from "Mild to Wild."

I would use a forged crank on a blown car. The belt pulls up on the crank and can cause stress. It will far out last the block

 

[1991vert]

There is some bad information in this topic. Even some coming from those saying there is bad information

Listen here...

First, I want to here why a 5.4" rod is preferred

Do the 5.315"/1.175" combination.

- There is NO oil ring intersecting into the ringland. This allows heat to penetrate into the oil ringland area. Heat chases away oil. You want oil in the piston pin boss.

- A shorter rod is also good for boosted and nitrous applications.

- There is more piston material on the 1.175" pistons.

- The only positive I see on the 5.4" rod is that it is a very slight difference in grams of weight.

Here is the deal with building a piston/rod combination where there will be little to no oil consumption issues. It depends on the builder. 99% of the engine builders (namely, local and some "professional") do not use proper piston to wall clearance, oil support ring land type and position, appropriately.

You cannot possibly say that you will have no problems with the 347 with the oil ring intersecting the wrist pin area.

Mark O'Neal from Coash High (Probe) and Barry R from Survival Motorsports are extremely knowledgeable and are in this very field being discussed. You want to know what they recommend for the street?

That is right, the 1.175"/5.315" combination

A Ford Lightning utilizes a completely different bore and stroke combination:

3.55 (bore) x 4.16 (stroke).

A SBF 302 uses a 4.00"/3.25" combination.

There is a big REASON why 99% of rods and pistons do not intersect in the automotive industry.

Now, for the rod ratio not being a factor. Sure, I agree with that. 99% of us do not need to worry about it for our purposes. However, Nascar uses a 1.93:1 rod ratio for a reason.

Some claim it is simply the by-product of the stroke and rod used. Nascar did testing and shortened the piston as much as possible to lighten it and utilize a longer rod. This gives a better rod ratio, aka, less frictional losses. Someone needs to pick up a book from John Heywood

In a world of extracting every last HP and engine longevity at 9-9500 RPM for 500 miles, they think of EVERYTHING. Thinking of everything is what determines the difference between #1 and #2. 2 HP can make or break a race over 500 miles. 2 HP just happened to be what the GM engines (358 CI) noticed from switching from a 5.250" rod to a 6.1" rod. Extreme example? Maybe, but there is truth. The Pro Stock guys are using 1.71:1 ratios.

Do not take this to an extreme. Rod ratio is typically highly exaggerated to most people. However, a good solid idea that I see in the professional world is a higher rod ratio as the RPMs increase.

Some may argue, well look at some of the foreign vehicles like Honda. Running 1.5:1 (similar) rod ratios, but look at their bore size. Very small.

The rings take the brunt of the wear. I actually have a formula to figure out the differences in side-thrust.

I often wonder why many credited engine builders want a thicker outside wall, than inside

You will see, per capita, higher rod ratios last longer than short rod ratios.

But, this is not something that any of us guys in here need to worry about.

If you want to read more about strokers, check out the link in my signature.

they move the rings...

 

[Grn92LX]

Yes Rick @ RHN is very good. From personal experience (unlike some) I have no problems with the 347 shortblock he built me in 2005

Well said 347HO