Close



Page 1 of 2 12 LastLast
Results 1 to 25 of 37
  1. #1
    FEP Senior Member
    Join Date
    Apr 2016
    Location
    Sprague River, OR
    Posts
    757

    Default Building vs. Buying a 347 Crate Engine

    After a few discussions with various people, I've decided to swap the idea of buying a 408W and go with a 347W instead. It's 50lbs less weight, it would fit under my OEM hood easier, and will be better suited for autocross.

    I'm doing some research on which would be a better idea, buying a complete 347 or building one on some level. Here's what I've come up with, assuming I'm going to get it all done before I pull my current engine 302 out:


    Building a short block:
    Craigslist find for a good 302 roller engine - $300
    Machining and prep for 347 - $500
    Scat bottom end from Summit Racing - $1,750
    Total ~ $2,550

    Building a long block:
    Adding AFR heads - $1,790
    Adding Scorpion roller rockers - $355
    Adding ARP head studs - $101
    Total ~ $4,800

    Building full engine:
    Adding camshaft kit - $525
    Adding oil pan - $70
    Adding valve covers - $70
    Adding Edelbrock RPM Air Gap intake - $287
    Total ~ $5,750

    Some will immediately say that this is not an exhaustive list of parts, and I will 100% agree. I am more convincing myself just to buy a complete engine the way I want it done (for the purpose of autocross and driving) rather than trying to eek out every penny and go the cheapest route.

    Blueprint Engines offers a 347 with 415 hp / 415 torque for $4,800 (long block).
    Prestige Motorsports has a couple 347 options between $6k - $6,600 for a long block.

    I haven't built an engine in 25 years. I have torque wrenches, slide calipers, and socket / ratchet sets. No micrometers, etc. Could I muster through it? Yes. But I do like the fact that it comes with a warranty from a builder, with a dyno sheet.

    What say you?
    Join The Conversation
    http://www.youtube.com/basinmotorsports

    '86 Hatchback V6 / Auto Restomod (For Sale)

  2. #2
    Moderator wraithracing's Avatar
    Join Date
    Jun 2010
    Location
    Grand Junction, CO/RR TX
    Posts
    14,206

    Default

    In general I would say that buying a long block from a reputable engine builder is often simpler and easier than building your own. Finding good local machine shops lately seems to be getting more and more difficult. Might be a bit more expensive, but there are several benefits. Just make sure that if you do decide to purchase from a builder that they are a reputable business and preferably one that specializes in SBF.

    I would double check your machining cost estimates with your local machine shops. My personal experience for quality machine work including vatting/cleaning, bore/honing, surface decking block, cam bearing install, etc. is generally more in the neighborhood of $750-$1000 in most cases. Your pricing may vary, but better to be safe than sorry. Besides you definitely want to compare apples to apples. Does your local machine shop use torque plates while boring/honing? That alone adds costs, but also generally adds 30+ HP to most engines.

    The only other point I would make, although it will not save you any $$ compared to a 347, I personally really like the 331 in a Mustang. Yes a bit less powerful, but does have some benefits over a 347 if you like to rev the engine or like a broader power band. Many of the 347 kits have solved some of the early oil consumption issues, but that can still be an issue with some 347 kits. The 331 also can be nice in regards to being able to put more actual power to the ground in many Mustangs due to less low end torque compared to the 347. If maximum HP/TQ is your goal, then the 347 is hard to beat, just keep in mind if using a stock block you can be at the upper end of the OEM strength. It just all depends on your ultimate goals and overall desires. Good Luck!
    Last edited by wraithracing; 12-04-2019 at 12:24 PM. Reason: Additional Comment
    ​Trey

    "I Don't build it hoping for your approval! I built it because it meets mine!"

    "I've spent most of my money on Mustangs, racing, and women... the rest I just wasted."

    Mustangs Past: Too many to remember!
    Current Mustangs:
    1969 Mach 1
    1979 Pace Car now 5.0/5 speed
    1982 GT Stalled RestoModification
    1984 SVO Still Waiting Restoration
    1986 GT Under going Wide Body Conversion Currently

    Current Capris:
    1981 Capri Roller
    1981 Capri Black Magic Roller Basket Case
    1982 Capri RS 5.0/4spd T-top Full Restoration Stalled in TX
    1984 Capri RS T-top Roller
    1983-84 Gloy Racing Trans Am/IMSA Body Parts

  3. #3

    Default

    FWIW I just built a 347 last winter. After much consideration and shopping around comparing online I decided to go with the ebay skip white rotating assembly kit with wiseco forged pistons and the normal cast scat crank. It was one of the cheaper kits, possibly the cheapest, considering it came with a balancer and flywheel etc.

    I was quite leery but in the end I took a chance and can say it all worked out very well for me. Being in Canada the shipping and duty can get very pricey so pushed me towards parts rather than a crate engine though. The intent was not to build a hardcore racing machine but a decent stroker more for saturday night cruising.

    For the shortblock assembly I found a stock bore 1988 roller block on kijiji for about $80 but the machining costs (all CDN dollars keep in mind) to check and prep the block was approx $1400 CDN for a full bore (line and cylinders) and torque plate hone decked with new cam bearings and ready for assembly etc. I did my own block clearancing with a die grinder save a few bucks.

    I sprang for the crank polishing, rod proofing, and flywheel extra options on the kit. Basic balancing was included which was a bonus in my book as thats about a $500 touch here. During assembly everything worked out nicely clearance wise with main and rod bearings. This was the part I was worried about as there is some conflicting info regarding some kits that needed a bunch of machine work after you get them...so was a happy camper.

    I also got a custom roller cam from FTI for my application ($500) and re-used my edelbrock rpm heads and intake from another other engine. It runs quite strong although I haven't got a lot of time to tune and play with it yet. Summers are too short here...

    That's what I did hope it helps !!

  4. #4
    FEP Power Member Hemlock's Avatar
    Join Date
    Jan 2007
    Location
    Quartz Hill, California
    Posts
    2,230

    Default

    Have to agree with Trey on the machine work, If I remember rightly I paid around $700 for the machine work on the block for my 347 for my RS and that was back in 2007. It is always cheaper to buy a "package deal" then it is to build your own. The advantage to building your own is no bargain parts will be used and you know the build is exactly what you want. What ever you decide to go with, the 347 is a great motor!

    Robert
    1984 RS 347 Capri, To many car parts to list, check out my car build page here for the story on my car and a full parts list/setup!:

    My RS in Action

  5. #5
    Venomous Moderator Hissing Cobra's Avatar
    Join Date
    May 2002
    Location
    Wareham, Massachusetts
    Posts
    9,720

    Default

    All 347's are not created equal. With that in mind, if you're using a stock block, why go with Forged crank/rods? To me, it makes no sense to put a $2,000 forged reciprocating assembly in a $200.00 block. It would also not make any sense going with a $1,000 cast crank/rods kit in an aftermarket Dart block. Just my thoughts on that.

    Anyway, It's going to cost you a minimum of $7,000 and as high as $10,000 for a streetable (take anywhere) 347, depending upon your wants/needs. It's the little stuff that you didn't list that's going to increase the pricing. Parts that you haven't mentioned include oil pump, good lifters (Morel?), hardened pushrods, guideplates, (if the AFR heads don't come with them), maybe a girdle on top of the rocker arms, MLS head gaskets, metal impregnated inside rubber oil pan and valve cover gaskets (much better than cork), intake gaskets, water pump, heater hoses, carburetor, air filter housing/filter, fuel pump, flywheel, balancer, etc...etc...etc....

    The sky's the limit but what do you want? I've got one that makes 420 rwhp/380 rwt and it's fully streetable. It'll idle at 1,000 rpms all day on 93 octane and it'll run mid 11's/low 12's in the quarter at 115-121 mph (also on 93 octane). I'll post my combo below.

    Stock Block
    Eagle 347 stroker kit (cast crank & rods) with SRP forged flat top pistons (10:8:1 compression)
    MLS Head Gaskets
    Metal Impregnated with rubber oil pan & valve cover gaskets
    Milodon Oil Pan and oil pump pick up
    Morel Link Bar Lifters
    Anderson N-91 camshaft
    AFR 185's (58 cc's with dual springs, adjustable guideplates, hardened pushrods, Comp Cams Steel Roller Rocker Arms, and AFR's valve train girdle)
    Edelbrock Victor Jr. intake manifold
    Holley 650 Double Pumper Carb
    Stock water pump
    Edelbrock mechanical fuel pump
    Romac Balancer
    Billet Steel Flywheel
    Centerforce Dual Friction Clutch
    Mac 1-3/4" longtubes
    MSD ignition (Distributor, 6AL, and Blaster II coil)

    I've seen 347's that make 302 power (choked by heads, intake, carb, exhaust) and I've seen 347's that make big block power. It's all in what you want and pricing can be all over the place as a result. If you're looking for a reputable one you may want to go on fordstrokers.com, as Woody builds some great stuff.

    I'm into mine for about $7,000 and that was with my brother doing the machine work and assembling it for me.
    Last edited by Hissing Cobra; 12-04-2019 at 06:19 PM. Reason: I added comments
    Pete Slaney

    1979 Mustang Cobra

    347/T-5/4.30's
    420 rwhp/380 rwt (New Motor)
    11.49 @ 121.86

    306/T-5/4.30's (Old Motor)
    307 rwhp/278 rwt
    12.38 @ 111.38

  6. #6
    FEP Power Member Jerry peachuer's Avatar
    Join Date
    May 2014
    Location
    Royal oak Mi
    Posts
    1,447

    Default

    You may want to skip the cast crank idea.. while back I had a bad cast crank break at the 1/5 main oil hole it split literally at the main oil hole where it was probably work hardened and stress riser was created but unseen on exterior..I'm not saying you need steel crank but it's great insurance policy
    and get everything balanced

    I tried to be slick with stock block cast crank 331 and good balance job at local shop where all work is done in house which wasn't important except it takes away finger pointing if something is not correct.. as far as warranty good luck with that .. 7 -1/2 months of emails back and forth with Ray at EAGLE almost makes me want to post the emails and replies for my misfortune.. Eagle would ask for a piece of information and I provided it with the shop who built my shortblock support with build detail and balance paperwork and serial number and bill of sale and clearances and tolerances and weights blah blah all proven and documented and backed by legit business
    It was 331 eagle kit with the sir I beam rods and the Pistons held up great and would buy them again they were SRP

    250.00 crank took out everything I mean everything including dizzy gear and not even a discounted offer for another crank

    My shortblock was 2500 and this included balancing and torque plate bore/hone and painted in 2011/12 or so
    I recently built the new stock ish motor in car now and I'm not mechanic but am a machinist and if you pay attention to tolerances and Fit's you will only be able to "assemble" not machine or if fitment issue arise you will need to take it to machine shop and get it worked

    Assembly is approx 275/300 I'd say and this is saved if you do it yourself if everything is perfect
    3 sets of bearings aren't cheap and you will need to buy at least 1 set and adjust from there if your not in tolerance so consider 2 sets of mains and 2 sets for rods

    What happens if you install cam bearings and there's 1 that's too tight and can't get cam in ? Machine shop min charge or knock it back out and rework it yourself and maybe buy another set of cam bearings for that 1 bearing you need


    Again this is something that you don't account for or like breaking that 1 piston ring and buy another set for that 1 ring


    I'm all about reusing and massaging parts and not trying to deflect your decision and sounds like you're aware of costs just trying to offer some other what if's

  7. #7
    FEP Power Member Jerry peachuer's Avatar
    Join Date
    May 2014
    Location
    Royal oak Mi
    Posts
    1,447

    Default

    Attachment 130469

    Don't be me buying 2 sets of rings bro lol Attachment 130470

    however I did make my own cam bearing tool

  8. #8
    FEP Power Member Jerry peachuer's Avatar
    Join Date
    May 2014
    Location
    Royal oak Mi
    Posts
    1,447

    Default

    Attachment 130471

    If you decide to build your own and install your own cam bearings the first bearing is going to fight you I used 2 home made shafts using the cam retainer plate and plastic wedge to start bearing square if you get this tweaked it will lock up your cam and it needs to be below flush .03/.06 thousandths

    Good luck on your decision

  9. #9
    FEP Power Member Jerry peachuer's Avatar
    Join Date
    May 2014
    Location
    Royal oak Mi
    Posts
    1,447

    Default

    First bearing meaning your last bearing you install (first bearing) on the outside behind cam sprocket

  10. #10

    Default

    I say go back to the 351w. Don’t stroke it and bore it. New good rod bolts and maybe a crank/rod undersize new forged higher comp pistons and send it. Best of all worlds plus #1 your not limited to the 400-500hp death toll of the roller blocks. Yeah it’s nice to have a roller, but I’d put that $$ into conversion for the 351 to roller and cyl heads in a 351w all day over the 347. More torque in the power band and wayyy more room for upgrades in the future when you can really afford a nice stroker kit.

    351w all day for <500 buy a set of good cyl heads, exhaust, intake, machine shop will be less than 600 and have them install the cam bearings

    No replacement for displacement if your a pushrod block. Stick with the 351 and you’ll be way happier. Who cares about a mere 50-65lbs when the weight is in the mains and structure of the block . Take it off you fenders and bumper brackets, your k-member & susp if you’re chasing every ounce. Get a hollow sway bar that may save you 15 right there . You’ll have piece of mind till 700hp.

    Don’t mean to de-rail you but that’s just my opinion.



    Sent from my iPhone using Tapatalk

  11. #11
    FEP Senior Member OX1's Avatar
    Join Date
    Feb 2009
    Location
    Jackson, NJ 08527
    Posts
    869

    Default

    Quote Originally Posted by Hissing Cobra View Post
    It's all in what you want and pricing can be all over the place as a result. If you're looking for a reputable one you may want to go on fordstrokers.com, as Woody builds some great stuff.
    Yeah, I had them do my Dad's LTD, 331 bottom end before he stopped using stock blocks.
    I figured the machine work has to be done by someone and he didn't charge that much for assembly,
    so why not have the bottom end done by a known pro (again, it's a little different now that his shortblocks
    are almost 5 grand with aftermarket block).

    With the blower, I didn't really need any more cubes, but the 331 didn't really cost anymore than a 302 would have,
    so figured why not. Have had zero issue with this combo, but it's a pretty mildly driven street/show car . This
    is the combo.

    http://luxjo.supermotors.net/DADSLTD...514_191039.jpg
    Last edited by OX1; 12-05-2019 at 04:06 AM.
    86 Capri, 5.0, 5Spd, A9L QH/BE, 47 lb Inj PMAS 3" MAF, Single T44 Turbo, Front Mount IC, TW170,
    Stock Cam, Explr Intake/TB, 1.7 Rockers, CF dual friction clutch, 3" DP, 2.5" full Exh, 3.27, 11.932 @ 115.78
    84 LTD, 331-10:1, TW170/Exprl Intake, 47 lbs inj/80 mm LMAF, Full Duals, Quarterhorse, Vortech 7PSI, Lentech AOD, 5 lug Mk VII brakes/rear, Eibach Sway bars, Cobra HB (dads ride, but I fix it )

  12. #12

    Default

    The extra 50-65lbs on the front of the car will have a massive affect in an autocross. It doesn't matter how much more power the 351 makes. It is guaranteed to be slower and significantly less fun the drive.

    If you do use this engine in the car to do track events, it is impossible to build a 347 for under $10k that will live a reasonable life. Most of the parts that Summitt and Jegs sell for these engines will not live very long when used in a constant 3,500-6,000rpm powerband. As someone above pointed out, if the crank breaks, it will destroy virtually everything in the engine. We've lost two engines over the years to valve failures, trying to use $1,500 cylinder heads. When the valve is dropped, it takes out almost everything. Crank, rods, block, cylinder head, etc.

    If the car is going to be used for open track events, I would not build a 347 on a stock roller block. It will just be a matter of time before it splits in half. I would go out and purchase a complete M-6007-D347SR engine or the circle track version if you want even better reliability. It has a block that won't split in half. The machine work will be done properly and it has some form of warranty. If you build your own engine, none of the parts suppliers will warranty anything.

    What is acceptable for durability in an engine that gets revved to 6,000rpm, 10-20 times per week for 5 seconds at a time will never live in an environment where the rpm is between 4,000 and 6,000rpm for 160 minutes per weekend. That is 100 times as much high rpm use.
    Jack Hidley
    Maximum Motorsports Tech Support

  13. #13
    Venomous Moderator Hissing Cobra's Avatar
    Join Date
    May 2002
    Location
    Wareham, Massachusetts
    Posts
    9,720

    Default

    Quote Originally Posted by OX1 View Post
    Yeah, I had them do my Dad's LTD, 331 bottom end before he stopped using stock blocks.
    I figured the machine work has to be done by someone and he didn't charge that much for assembly,
    so why not have the bottom end done by a known pro (again, it's a little different now that his shortblocks
    are almost 5 grand with aftermarket block).

    With the blower, I didn't really need any more cubes, but the 331 didn't really cost anymore than a 302 would have,
    so figured why not. Have had zero issue with this combo, but it's a pretty mildly driven street/show car . This
    is the combo.

    http://luxjo.supermotors.net/DADSLTD...514_191039.jpg
    It looks to be a nice combo. I'm sure he has fun with that! I'm aware that Woody no longer uses stock blocks because they have a high rate of failure in a stroker application. There's a lot of merit that these blocks can only handle 500 hp (give or take) but you'll get into arguments with a lot of people in regards to that. To me, there's a difference between having a car that you can race and take to that 500 hp level consistently and those that are dyno queens/show cars that never see that type of rpm. I see a lot of 347's that make 500, 600, 700 at the wheels on a stock block but they're never at the track and using that rpm/horsepower level on a regular basis. Simply cruising around town at 2,000-3,000 rpms and taking it to car shows, cruise nights, etc.... will not stress them out to the point of breaking and they'll last forever (with that one bonzai run on the dyno to "get the numbers"). Lean on them consistently with 6,000 - 7,000 rpms shifts and high cylinder pressures, and you'll see the main caps walking all over the place. Then it's only a matter of time before they go BOOM.

    If my stroker breaks to the point of catastrophic failure, I'll be looking at going with a 351W (as long as I can get it under the stock hoood/hoodscoop) where I can make the same power with less stress on the block.
    Pete Slaney

    1979 Mustang Cobra

    347/T-5/4.30's
    420 rwhp/380 rwt (New Motor)
    11.49 @ 121.86

    306/T-5/4.30's (Old Motor)
    307 rwhp/278 rwt
    12.38 @ 111.38

  14. #14
    FEP Super Member mmb617's Avatar
    Join Date
    May 2005
    Location
    Altoona, PA
    Posts
    4,249

    Default

    When I built my engine I went with an assembled short block because I don't have the tools or experience to do that part myself, and I don't know of any reputable local machine shops. I thought that would be the most cost effective way to build, but the costs add up fast and I'm not really sure if I saved any money over buying a complete crate engine. I ended up with over $7k in the engine and that was 12 years ago. It also wasn't a real high end build, those costs could have easily went up another couple grand with different part selection.

    I enjoyed building the engine myself, so that was a plus, but if I were doing it again I think I'd take a hard look at a crate engine.

    I doubt if a decent engine could be built up for under $10k and that's right in the ballpark of a crate engine.
    408/T5/3.73's

    We're not fast racers, we're more what's known as half fast racers.

  15. #15
    FEP Super Member NAVYCAT's Avatar
    Join Date
    Jul 2004
    Location
    Montebello, CA
    Posts
    3,435

    Default

    IMO I would buy the short (or long block) because it will have a 3 yr warranty just in case.
    2017 Ford Explorer Sport (DD) 1986 Capri 5.0 Silver/Red
    1969 Falcon XW GTHO coupe (SOLD) went to Australia
    Past 4 eyes-
    4th. 1981 Capri "White" Black Magic I6
    3rd. 1984 Capri RS V8 Black/grey
    2nd. 1984 Capri RS V8 White/red
    1st. 1984 SVO Grey/grey (traded it for a worn out 1970 BOSS 302)
    Both '84 Capri's vin# were 10 away from each other
    U.S. NAVY 1980-2009

  16. #16

    Default

    Quote Originally Posted by NAVYCAT View Post
    IMO I would buy the short (or long block) because it will have a 3 yr warranty just in case.
    What’s the OP’s car used for? Is this a track only car or street driven?


    Sent from my iPhone using Tapatalk

  17. #17
    FEP Senior Member
    Join Date
    Apr 2016
    Location
    Sprague River, OR
    Posts
    757

    Default

    Quote Originally Posted by 82MoreDoorFox View Post
    What’s the OP’s car used for? Is this a track only car or street driven?
    It is targeted for 50/50 track (autocross) and street. For SCCA CAM it needs full interior, so it will stay somewhat comfortable. I like Jack's suggestion of a circle track Ford engine, as it will be designed for anything I can throw at it and has a warranty. It would need a couple parts changed to match a Fox platform, but it'd be easy to swap before adding to the car. The best I could find on the engine price was around $8,700, which would probably be comparable to a custom built one that could match the durability. It could be built for more power and torque, but as Jack said, it probably wouldn't have the same longevity.
    Join The Conversation
    http://www.youtube.com/basinmotorsports

    '86 Hatchback V6 / Auto Restomod (For Sale)

  18. #18
    FEP Super Member xctasy's Avatar
    Join Date
    Jun 2012
    Location
    Dunedin 9011, New Zealand, South Pacific
    Posts
    3,961

    Default

    Quote Originally Posted by Basin Motorsports View Post
    After a few discussions with various people, I've decided to swap the idea of buying a 408W and go with a 347W instead. It's 50lbs less weight, it would fit under my OEM hood easier, and will be better suited for autocross.

    I'm doing some research on which would be a better idea, buying a complete 347 or building one on some level. Here's what I've come up with, assuming I'm going to get it all done before I pull my current engine 302 out:


    Building a short block:
    Craigslist find for a good 302 roller engine - $300
    Machining and prep for 347 - $500
    Scat bottom end from Summit Racing - $1,750
    Total ~ $2,550

    Building a long block:
    Adding AFR heads - $1,790
    Adding Scorpion roller rockers - $355
    Adding ARP head studs - $101
    Total ~ $4,800

    Building full engine:
    Adding camshaft kit - $525
    Adding oil pan - $70
    Adding valve covers - $70
    Adding Edelbrock RPM Air Gap intake - $287
    Total ~ $5,750

    Some will immediately say that this is not an exhaustive list of parts, and I will 100% agree. I am more convincing myself just to buy a complete engine the way I want it done (for the purpose of autocross and driving) rather than trying to eek out every penny and go the cheapest route.

    Blueprint Engines offers a 347 with 415 hp / 415 torque for $4,800 (long block).
    Prestige Motorsports has a couple 347 options between $6k - $6,600 for a long block.

    I haven't built an engine in 25 years. I have torque wrenches, slide calipers, and socket / ratchet sets. No micrometers, etc. Could I muster through it? Yes. But I do like the fact that it comes with a warranty from a builder, with a dyno sheet.

    What say you?
    In this instance, an alloy headed Windsor 9.5" deck, or a Cleveland 351 9.2" block with A3 style heads.

    IMHO, the Stroker 347s with stock blocks are a no no unless you show some extreme discipline and cap the revs and hp down;

    Fords last Explorer/Mountaineer based 335 hp/369 lb-ft iron headed 5.6 liter in the last Falcon T3's was a sensational M/R/Q code Cleveland 351 or 371 hp style Saleen Windsor 351 without the alloy heads. The car had hypereutectic pistons and just a really nice EFI intake with a low rent 1999-2001 5.0 SUV grey iron thin-wall block, but it had reverted to GT40P iron heads and a main girdle to tie its block together.

    Tall deck engines have a wealth of answers Ford provided in the late 60's to making S code 390 power with little small block 351s:

    The extra 38 pounds the Cleveland carries over the 351W, and the extra 55 pounds the tall deck 351w carries over the 302w, it all reduces the "lambda" L/R side thrust forces hitting the blocks cylinder walls, and there is more crank journal, main bearing area and the extra 1.00 to 1.294" of deck gives a proper 5.78 to 5.936" rod that unloads the cylinder walls in an engine that easily gives 400 to 630 hp at much lower revs.

    An old junked 351C or 351W that hasn't been bored will need 30 thou to clean up the walls, and your 55 to 93 pound weight penalty is taken care of by alloy heads and the Maximum Motors K member drop plates, which means everything goes under the hood.

    For me, a 1978-1981 351M has the toughest crack free small block castings ever, Ford fixed those nasty thin wall 351C's with a taller deck 10.322" engine; The 351M was a 400 engine destroked. With a 4" stocker 400 crank, it would just fit under the hood with Maximum Motors K member drop plates.

    That engine can make 750 hp with factory 4V style parts, and a 150 pound weight penalty. Pretty cool considering the last year it was in the F150 truck as an option, it made just 136 hp.

  19. #19
    FEP Super Member xctasy's Avatar
    Join Date
    Jun 2012
    Location
    Dunedin 9011, New Zealand, South Pacific
    Posts
    3,961

    Default

    This is the risk





    I've got all "mustangxtreme's" old 81Black-Magic 400 Ford swap pictures on Photobucket.


    Ford had the 9.2" tall deck 3.8 in the Fox, they fixed the hood height with better ancillary drives and reduced height air cleaners.

    "http://vb.foureyedpride.com/showthread.php?128044-81-Black-Magic/page3"

    Serpentine drive 351C, check






    The other stuff is easy.










    4V intakes can be flitched together from common alloy Aussie 351 4v's or you can find 400 4V after market intakes


    The weight and center of gravity height is taken care of by the MM k member kit, the 31 pound lighter 4V intake, and the 50 pound lighter aftermarket heads.

    And you can really stand on the 351M block.

    https://www.hotrod.com/articles/1002...ngine-rebuild/

  20. #20

    Default

    Good info I did not know about the 351M blocks. And since he is full interior and 50/50 street track. I still stand by either one of the 351M or 351W. And I can not for the life of me pay 8700 for a long block. I say buy the 351W have the shop build the short block and slap your heads on and build the rest yourself. 8700 would cover shop/machine work K-member, heads and some liquid courage.


    Sent from my iPhone using Tapatalk

  21. #21

    Default

    Good info I did not know about the 351M blocks. And since he is full interior and 50/50 street track. I still stand by either one of the 351M or 351W. And I can not for the life of me pay 8700 for a long block. I say buy the 351W have the shop build the short block stock crank And rods / better bolts and slap your heads on and build the rest yourself. 8700 would cover shop/machine work K-member, heads and some liquid courage.


    Sent from my iPhone using Tapatalk

  22. #22

    Default

    There is money and there is your goals. If you just want some fun and a 500hp limit is fine with you, then a stock block cast crank 347 may suit you just fine. Maybe just get a good short block first. Things like aftermarket heads, cam and intake are pretty easily swapped later when you have the money and maybe better know what direction you want to take the car.
    Black 1985 GT: 408w, in the 6's in the 1/8 mile
    Bimini Blue 1988 LX 5.0 Coupe 5-speed, Hellion turbo, zero options
    Grabber Yellow 1973 Mustang Mach 1: 351c, toploader
    Black 2012 5.0 GT, 6-speed, Brembo brakes, 3.73's
    Wimbledon White 1966 F-100 Shortbed Styleside, 390, Tremec 3550, FiTech EFI

  23. #23
    FEP Super Member xctasy's Avatar
    Join Date
    Jun 2012
    Location
    Dunedin 9011, New Zealand, South Pacific
    Posts
    3,961

    Default

    Hey there Zap's 85 GT! I think a steel crank is a crutch for the problem with the small main bearing 302 block.

    The guys at Ford during the advent of 1983 SVO era decided to make a race 5.0 block, a race dual use Windsor-Cleveland 9.2 or 9.5 block for NASCAR as a replacement for the stock production Windsor and Cleveland 351's.

    In 1969, the bigger main bearings allowed a simplified down grade to nodular iron for production 351's, 351C's and 351M's, and they don't break easily. Nor do blocks.

    The 347 needs to never split, or your investment in parts is gone, and that's money down the drain.

    Drastically limit the RPM and HP for any 347, or upgrade to a performance race spec block.

  24. #24

    Default

    The crank breakage problem is a function of the 50oz-in imbalance. Ford wanted to make the engine weigh less, so they removed as much weight as possible from the crank in the center of it. This required more offset weight in the balancer and the flywheel so that the OVERALL assembly (crank + balancer + flywheel) is balanced. This does result in less overall weight, but it also creates very high bending loads in the crank. These bending loads are the primary source of crank failures at the first journal. Another contributing factor is the inertia of the timing chain and the FEAD on the front.

    I'm sure that the crank flexing greatly increases the chances of splitting the block in half. If you build the engine with a 28oz-in or internal balance, the crank is much, much less likely to fail. I believe that this will also reduce the chances of the block splitting in half. It doesn't make it zero because the crank still flexes as it is not built symmetrically. To eliminate most of the flex in the crank, it would have to have center counter weights. If you build one with center counter weights, then the only flexing that occurs is within each cylinder pair, rather than across the entire length of the crank.

    I totally disagree about the weight issues from taller deck blocks. The power to weight ratio of a car in an autocross has very little to do with how fast it is. Consider two cars that run the same times, one with high power and poor handling. The other with lower power and good handling. The second car is so much more fun to drive.

    A Fox Mustang has a horrible percentage of its weight on the front tires. Around 57% depending on model. You need to do everything possible to improve this, if you want the car to handle better. Remove weight where you can in the suspension. Install aluminum cylinder heads. Relocate the battery to the back or middle of the car. Move the front tires forward, if at all possible. Even once you do all of this, the car is still going to be around 53% front weight.
    Jack Hidley
    Maximum Motorsports Tech Support

  25. #25
    FEP Senior Member
    Join Date
    Jun 2003
    Location
    Santa Maria Ca
    Posts
    743

    Default

    I hate to throw out this dollar-grenade, but for another 1,700 bucks you can have a dart block 363.

    I’ve been struggling with the same issues on a build I’m planning. The machine costs have made doing it myself prohibitive. All the custom parts really start to add up. I figure when all is done a 10k budget isn’t that outrageous.

    I did hear from a guy with a Blueprint 347 that had problems and they made it right. This was good to hear. It was a couple years back though, so hard to say what happens today.
    85 Saleen Mustang(s)

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •