331 stroker assembly recommendation - Vintage Mustang Forums
 14Likes
Reply
 
Thread Tools
post #1 of 22 (permalink) Old 03-21-2018, 09:08 PM Thread Starter
Senior Member
 
Join Date: Nov 2015
Posts: 118
331 stroker assembly recommendation

So, been looking to pickup a 331 rotating assembly for my 68 using 5.0 roller block. Was going to go with a cast crank setup but after a bit of research the cast cranks seem to be having a high failure rate, even at 350 hp, from Eagle, Scat, RPM. They all getting from the same foundery in China?
Will be using TFS 11R 190 heads and a custom roller cam so HP should in the 400s. Won't be doing any drag racing but will get on it once and awhile with autocross and RR track events. Again, the only companies I have looked into for budget setup are Eagle, Scat, RPM.
Should I be looking into the 4340 cranks?
Are H-beams necessary?
I have no flywheel or balancer so can go internal or external. Should I just go with internal balance crank?

Any advice and experience with these kits would be greatly appreciated!

J
jsulse is offline  
Sponsored Links
Advertisement
 
post #2 of 22 (permalink) Old 03-21-2018, 09:30 PM
Senior Member
 
Nailbender's Avatar
 
Join Date: Jan 2015
Location: Northern Indiana
Posts: 2,319
I have a budget Scat cast crank in my 331 and have had numerous issues including the end of the Scat crank not matching the end of the factory crank contributing to several thrust bearing failures. I would get the best crank available because the forged cranks are "supposedly" still finished in the US. ALL cranks cast or forged come from China. Callies does not appear to offer a US made crankshaft anymore.

My advice, regardless of which crank you choose, is to make sure the end flange of the new crank matches the end of the old crank in every way. This might require a competent machine shop. Good luck with that!
Rowdy likes this.

65 C Code hardtop from California still wearing it's original paint.
Roller 331, TW 170 heads, T-5z, FiTech EFI, HiPo Manifolds, Arvinode exhaust, SoT Bilstien coilover front suspension, TJ on eBay 8" 3.40 Trac-Loc 3rd member. Mustang Steve 2008 GT bracketed 12.4" front disks
Nailbender is offline  
post #3 of 22 (permalink) Old 03-21-2018, 10:22 PM
Senior Member
 
jdub's Avatar
 
Join Date: Dec 2011
Location: Colorado
Posts: 4,400
No reason not to build a 347 over a 331.
j persons, Israel and cmefly like this.

1965 Mustang
jdub is offline  
 
post #4 of 22 (permalink) Old 03-22-2018, 12:07 AM
Super Moderator
Supporting Member
 
Israel's Avatar
 
Join Date: Feb 2011
Location: New Orleans
Posts: 8,633
More is better,.....

Ex-wife,....."You drove how far for that thing?"
Daughter,..."Theres no inside and it stinks."
Friend,......."Dude, thatís a rusted pile."
Son,.........."This old car is cool."

USMC Security Forces, Kamiseya Japan, 0311

Build Thread: http://forums.vintage-mustang.com/vi...sted-pile.html
Israel is offline  
post #5 of 22 (permalink) Old 03-22-2018, 01:56 AM
Senior Member
 
sportsroof69's Avatar
 
Join Date: Mar 2009
Location: Somewhere down in Texas
Posts: 5,365
Cast crank failures? In what way? I pushed a Scat cast crank deep into the 9s and have spun it over 7K RPMs a lot of times. A forged crank and H beams rods are a waste of money in a 302 block, because the block itself is the weak link. I have heard of issues like Nailbender had, which can be taken care of before you ever start it, but I’ve not heard of a crank failure in a 302 block, that wasn’t caused by something else.
cmefly likes this.
sportsroof69 is offline  
post #6 of 22 (permalink) Old 03-22-2018, 02:58 PM Thread Starter
Senior Member
 
Join Date: Nov 2015
Posts: 118
Agree, more is better, 347. Just was concerned of oil control issues and rod ratio, both of which seem to be unwarranted. Was considering 351 but that is getting too involved with the direction of my EFI build. Would like to use Victor Jr EFI multiport which is not made for 351. Price Motorsport makes a spacer kit but would rather not go down that path. Plus, I intend to use 1999+ Explorer cam syncrhonizer and crank position sensor for LS style coil near plug. I can make a hybrid cam synchronizer from 3.8 V6 and Explorer units that fit 351 block but again, non stock custom parts head ache.

Well, I think I need to talk to Fordstrokers and let them guide me. They have Scat cast 9000 28oz rotating assembly and an entry level RPM 4340 assembly which is internally balanced. Let them balance in house and be done with it.

The pics I seen on around the web cranks literally cracking in half. May have been result of a bad batch of castings, who knows.
jsulse is offline  
post #7 of 22 (permalink) Old 03-23-2018, 10:17 AM
Senior Member
 
Lukesportsman's Avatar
 
Join Date: Apr 2004
Location: Western Indiana
Posts: 1,263
In an email just this week. Randy from RM Competition (engine masters fame) told me outside of class racing he saw no real advantage of 331 over 347 and that'd it cost more. What I've also noticed is that its more difficult to find a 28oz 331 assembly. I was leaning towards the 331 for T5 life and piston ring position. He said just soften the torque hit of the 347 with intake or cam selection.

69 351 TKO Sport Roof, Ride Tech coilover
70 557 PG Mach I tube chassis 2650lb
70 427 TKO Sport Roof, SoT full chassis to be
70 351 FMX Mach I
67 347 TKO Coupe SoT/CAT5
67 289 C4 Coupe stockish cruiser
69 460 TKO Vert, Mustang Plus Grab a Track
94 351 TKO AIX, Maximum Motorsports
01 5.4 4L80E Twins and CrMo caged
11 5.0 Magnum XL single turbo Griggs
Lukesportsman is offline  
post #8 of 22 (permalink) Old 03-23-2018, 11:02 AM
Senior Member
 
cmefly's Avatar
 
Join Date: Mar 2011
Location: Bonney Lake
Posts: 4,393
Quote:
Originally Posted by jsulse View Post
So, been looking to pickup a 331 rotating assembly for my 68 using 5.0 roller block. Was going to go with a cast crank setup but after a bit of research the cast cranks seem to be having a high failure rate, even at 350 hp, from Eagle, Scat, RPM. They all getting from the same foundery in China?
Will be using TFS 11R 190 heads and a custom roller cam so HP should in the 400s. Won't be doing any drag racing but will get on it once and awhile with autocross and RR track events. Again, the only companies I have looked into for budget setup are Eagle, Scat, RPM.
Should I be looking into the 4340 cranks?
Are H-beams necessary?
I have no flywheel or balancer so can go internal or external. Should I just go with internal balance crank?

Any advice and experience with these kits would be greatly appreciated!

J
Scat cast crank, Scat or eagle I beam rods and a good forged piston is all you will need. You will split the stock block before you break the crank. Forget the 331 and just build a 347. I have both 331 and 347 using similar parts the 347 made 25 more HP and 25 ft lbs of torque at a lower rpm. Nothing wrong with 28 ounce external balance for what you are building.
cmefly is offline  
post #9 of 22 (permalink) Old 03-23-2018, 12:48 PM
Senior Member
 
Join Date: Oct 2015
Location: Anaheim
Posts: 1,052
I am constantly amazed at how much money is wasted on building stroker engines. Choose a target for the horsepower you want and build to that goal. As others have warned , you have a power limit on the roller cam block ( very safe) of 400-450 hp. Next look at the crankshaft. The amount of change in stroke is from 3.00 to 3.400 or .400 , which is "actually" only .200 ( less than a 1/4") because the crank moves the piston up .200 and down .200 for the total increase. This adds very little to the centrifugal force (or load) on the crank. It is still shorter stroke than a 351W( or C). A cast crank will not break in "normal" use . Journal accuracy is more important than the material in this case. I am not a fan of the 'SIR" or super cheap I beam rods as they are more "spindley" than a stock rod. "I" like the RPM nut and bolt , machined beam , double rib cap , economy rod , much better than the SIR or Scat "cheapie" rod even though they have cap screws. It is "my" preference only. Forged pistons are important and on "street" engines I suggest the 4032 high silicon , low expansion material. the pin in the wrist pin "issue" was a product of Probe's inability ( initially) to produce a "stable" piston . They did cure that situation and eventually made pistons "with" pins in the oil ring groove but kept the "myth" alive.
There is NO reason to put 700hp, 9,000 rpm components in a block with limited capabilities or power output. For those who use "insurance" as an excuse or reason , you 700hp capable parts will still be JUNK when your 450hp block fails , your extra money spent bought you nothing. IF your goal IS 700+ HP by all means buy the BEST parts you can afford starting with the block , forged crank , H beam rods , etc.
120mm and Dan Babb like this.

'66 GT350H-3 time cover car - Car Craft July'77,Modified Mustangs and Fords Feb2011 ( w/article), Mustang Monthly June 2014. Bracket raced by me for the last 44 years. Yes it is a real one.
'68.5 R code GT fastback
'67 Ranchero 408W -427 glass hood
'78 F350 "Oleynik" car hauler
Ford Experimental parts collector
GT350HR is offline  
post #10 of 22 (permalink) Old 03-24-2018, 09:23 AM
Senior Member
 
buckeyedemon's Avatar
 
Join Date: Dec 2007
Location: Cincinnati, OH
Posts: 2,966
i know it seems taboo to talk forged crank in a stock block on the internet, but I've often wondered if a stronger/stiffer crank (not talking brittle) and one without the extra imbalance hanging on the outside of the mains, could help reduce the probability of the 302 blocks splitting. does a weaker/flexier crank, cause more bearing stress/main stress/walk at the mains closest to the cylinder that fired (or pre-ignited)? with a stiffer crank it seems like possibly that load on the block could be shared a little more across more than just the local two mains encompassing that cylinder. i'm sure getting data for this is pretty much impossible and i'm sure many with a forged crank have split a block.

buckeyedemon is offline  
post #11 of 22 (permalink) Old 03-24-2018, 07:20 PM
Senior Member
 
cmefly's Avatar
 
Join Date: Mar 2011
Location: Bonney Lake
Posts: 4,393
Quote:
Originally Posted by buckeyedemon View Post
i know it seems taboo to talk forged crank in a stock block on the internet, but I've often wondered if a stronger/stiffer crank (not talking brittle) and one without the extra imbalance hanging on the outside of the mains, could help reduce the probability of the 302 blocks splitting. does a weaker/flexier crank, cause more bearing stress/main stress/walk at the mains closest to the cylinder that fired (or pre-ignited)? with a stiffer crank it seems like possibly that load on the block could be shared a little more across more than just the local two mains encompassing that cylinder. i'm sure getting data for this is pretty much impossible and i'm sure many with a forged crank have split a block.
I am guilty of using the Forged crank in both my 331 and 347 with the stock block. Both engines have a girdle so hopefully if the block does split I will not drive over the crankshaft. Was not by choice just worked out that way. I beat on my little 331 in my 65 Falcon shifting at around 6700, so far no split block. Cool Falcon any more pics?
cmefly is offline  
post #12 of 22 (permalink) Old 03-24-2018, 09:22 PM
Senior Member
 
Join Date: Sep 2006
Location: Hayward,CA
Posts: 827
I have been thrashing on an Eagle forged crank with zero balance(internal) and H beam rods also from Eagle. Motor was pro built with very few expenses spared. Lots of other specs but those addressed are answers to the thread. I am using a Mexican block with girdle and all studs. It's been working great for over 450 engine hours.

http://i863.photobucket.com/albums/ab200/aslaned/unnamed_1.jpgChuck Wiltens
MCA Gold card - Modified - Judge
Assistant National Head Judge-3rd Generation
MCA#50308
trkpny2 is offline  
post #13 of 22 (permalink) Old 03-25-2018, 05:06 PM
Senior Member
 
buckeyedemon's Avatar
 
Join Date: Dec 2007
Location: Cincinnati, OH
Posts: 2,966
Quote:
Originally Posted by cmefly View Post
Cool Falcon, any more pics?
no responses in the last 20 hours so here goes.... pics at various stages of mock up. all motor 447ci sbf (~13:1 pump gas), modified T-56 magnum, Strange S-Trac helical/35 spline, 8.5 moly cage w/removal door bars, optional headrest/window net, heavily modified floors to tuck the 3.5" exhaust (304 stainless from cylinder head to bumper), 5" travel Afco's front/back (6.7" travel in the front with optional travel limiters)....

























buckeyedemon is offline  
post #14 of 22 (permalink) Old 03-25-2018, 10:38 PM
Senior Member
 
sportsroof69's Avatar
 
Join Date: Mar 2009
Location: Somewhere down in Texas
Posts: 5,365
Quote:
Originally Posted by buckeyedemon View Post
no responses in the last 20 hours so here goes.... pics at various stages of mock up. all motor 447ci sbf (~13:1 pump gas), modified T-56 magnum, Strange S-Trac helical/35 spline, 8.5 moly cage w/removal door bars, optional headrest/window net, heavily modified floors to tuck the 3.5" exhaust (304 stainless from cylinder head to bumper), 5" travel Afco's front/back (6.7" travel in the front with optional travel limiters)....


I love it. Looks awesome.
sportsroof69 is offline  
post #15 of 22 (permalink) Old 03-26-2018, 04:02 AM
Senior Member
 
Join Date: Oct 2014
Location: Amish Wonderland of Central PA
Posts: 621
A lot of awesome work going into that Falcon! Good Job!

Dennis

65' Stang Street/Strip:



Dart 434W NA, G101A 4 Spd, 4:56 rear, 93 octane pump gas pushing 3550lbs. [email protected]
dennis111 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Vintage Mustang Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off

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