Engine build

[1969-Mustang-ZX-427 11]

Alright so most of you have seen my 390 engine build plans but I've changed them, a lot of you guys had made me realize how expensive everything would be and i added it all up and it came up to around $20000 to build it including everything to convert my 69 to a v8 and plus since I'm not planning on installing it any time soon, so it just wouldn't make since to waste all that unnecessary money so I have came across an old plan I was thinkin of when I bought the car, I've found a ford racing 427 v8, can i install a rear sump on the v8 suspension or just stick with front sump? I have more questions as well, which is better, 1 carb or 2 and I'll ask more later, just wanna get my notes down, car will not be used as drag or race, mostly daily driver and show sometimes

Here's the engine http://www.fordracingbyspeedshopdirect.com/mobile/product.aspx?ProductCode=m%2D6007%2Dz427frt&404;http://www.fordracingbyspeedshopdirect.com:80/427_Cubic_Inch_535HP_Rear_Sump_Crate_Engine_p/m-6007-z427frt.htm=

[barnett468 418]

well, imo, that thing is going to want a port matched vic jr intake and a 780 to 850 cfm ss or q series quick fuel carb or similar.

 

2 carbs are mainly for show but will work.

 

1 7/8 tube headers that match the exhaust port size.

 

3" tail pipes

 

i would stick with the original style with a baffled, large volume pan.

[Rsanter 152]

Front,sump, easy swap

[moodster 55]

I think you'll have 20k in that option as well... what is your budget?

[sportsroof69 13]

Single carb, front sump.

[1969_Mach1 333]

I think you'll have 20k in that option as well... what is your budget?

 

That was my thought. If the 390 was out of budget, is the 427 feasible? Of those two choices, I'd be inclined to stick to a 390 build. It seems more realistic.

[Pakrat 1,043]

Isn't dreaming big what your early 20's are all about though? I say go for it if you can, the harsh reality of age and obligation sets in way too fast!

[1969_Mach1 333]

That very true!

[LiLMike 42]

Back in the day, we used a 428 crank with 427 connecting rods and the old Mercury 410 pistons. You may be able to get that from summit racing but an easier way would get a stroker kit for the 390. With the stroker kit, heads, cam and intake you can easily get 450-500 hp for a reasonable amount. Put a few more dollars into it and you can pump that up to 550 easily! Check out the 390 stroker articles online. I'm sure you can find something. I know years back Hotrod magezine had the how to on it.

[jholmes217 65]

If you want to go the FE engine route, I highly recommend you look at Survival Motorsports. All they do is FE engines. http://www.survivalmotorsports.com/

Barry Robotnik is the owner, and he regularly enters FE engines in the Engine Masters Challenge.

[barnett468 418]

.

That 427 crate engine is from a boss 351 windsor ford racing small block . . it is a great block but you could probably build a better one for a little less . . you could even buy any used 351 block and build it to 418 but i would not build it past 408 due to the increasingly poor rod to stroke ratio. . the later 351's are roller ready which will save you some money on lifters but the lifters won't be quite as good.

 

The set up below will be FAR better than the crate 427 and it will cost less.

 

i and others can tell you how to easily get over 500 hp with any 351 block.

 

below is just 1 option.

 

used 351 block - $150.00 - $500.00

 

machine block so pistons are around .003 below the block deck.

 

 

BOSS 351 block . Same one they use for the 427 $2050.00

 

http://www.summitracing.com/parts/fms-m6010boss351?seid=srese1&gclid=CKq8mOvk0MICFQmNaQodLoUAUw

 

 

cost to bore to proper size - $200.00

 

cost to “0” deck and square to the crank, which they do NOT do on the ford 427 crate engine $200.00

 

 

418 BIG BORE KIT - this fits original windsors only . . it will not fit a new ford or eagle block because they use a smaller crank diameter, however you can make up a kit for the new blocks for the same price . . 19 cc’s pistons but you need flat top pistons, internal balance, 4.100 stroke, 4.030 bore $2400.00 . . you can change stroke and pistons for around the same price . . this kit is for an orig windsor block which has a 3.00" main journal . . the new ford and dart blocks use a cleveland size 2.79 main.

 

http://www.summitracing.com/parts/sca-1-47510bi/overview/make/ford

 

 

if you build your own kit i might use this 4.0 stroke internal balanced, knife edged crank for the original windsors $725.00

 

http://www.summitracing.com/parts/kot-011fad400/overview/make/ford

 

 

use this one for the new blocks $725.00 . . uses .940 wide rod.

 

http://www.summitracing.com/parts/kot-011ead400/overview/make/ford

 

 

these eagle rods are nice and have doweled caps like the scats, 665 grams, 6.2 long for 2.1 crank journal, arp bolts, .940 wide $540.00

 

http://www.summitracing.com/parts/esp-6200b3dl19/overview/make/ford

 

http://www.summitracing.com/parts/esp-6200b3dl19-1

 

 

or scat lightweight I beam rods 620 grams $520.00

 

 

probe pistons for 6.2 rod, 4.0 stroke, 9.480 [69 thru 72 block] block height . . 9.5 blocks should be milled for 0 deck height to improve quench/squish distance.

 

probe pistons $465.00

 

http://www.summitracing.com/parts/pbp-12357-030/overview/make/ford

 

 

or use an eagle 6.250 rod with 4.0 stroke

 

http://www.summitracing.com/parts/esp-6250b3d2000/overview/make/ford

 

 

srp 1.23 height for 9.480 blocks 4032 alum with 1/16” rings, $525.00 . . can be used with 9,5 blocks but it is best to mill them to 0 deck to improve quench/squish distance.

 

http://www.summitracing.com/parts/srp-206057-8/overview/make/ford

 

 

mahle 1.245 height for 9.5 blocks, not early 9.480 blocks $600.00 with moly plasma rings

 

http://www.summitracing.com/parts/mle-sbf245030f06

 

 

je 1.25 height for 9.5 blocks, not early 9.480 blocks $750.00

 

http://www.summitracing.com/parts/jep-188704-8/overview/make/ford

 

 

moly plasma rings $120.00 . . not needed with complete stroker kits.

 

 

for around $1920.00, using the separate parts above, you have a killer 4.0 inch stroker rotating assy [minus bearings] that is a little better than the ford one.

 

 

AFR 205 heads $1870.00

 

http://www.summitracing.com/parts/afr-1458/overview/make/ford

 

 

Ford Racing Z304 heads on 427 . . $2200.00 . . These are MORE than the AFR heads and are NOT as good . . See flow chart below.

 

http://www.summitracing.com/parts/fms-m6049z304da

 

 

Use this cam or similar for a roller block with 1.60 rockers . . I would have it ground on a steel blank . . If you use a non roller block, have it ground on a retrofit profile for lifters with a .750 wheel $240.00 - $340.00 . . or get a custom cam from cam research, bullet cams or straub technologies.

 

http://www.lunatipower.com/Product.aspx?id=1671&gid=289

 

 

or this cam ground with a 112 lsa in steel for .750 roller wheel lifters . . use 1.65 rockers with it.

 

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=1068&sb=0

 

 

or this retrofit cam with 1.65 rockers

 

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=898&sb=0

 

 

Scorpion race series rockers - $240.00

 

Rollmaster timing chain set - $135.00 way better than the ford crate eng chain.

 

mellings oil pump and high perf drive shaft $120.00

 

high volume baffeled oil pan [optional] $250.00

 

Morel lifters - $750.00 p/n 5979 or 5879 . . you can buy other brands for less or the lower cost small wheel morels for around $550.00, tbut these are xlnt and way better than the ford crate eng lifters . . ask lunati if they sell them . . they repackage them . . if they do they might cost less from them . . confirm that they will work in the particular block you use.

 

engine balance - $200.00

 

gaskets - $100.00

 

.080" wall chromoly push rods - $80.00

 

engine assembly - $700.00

 

ATI crank damper . Way better than any other by FAR for street apps same brand used by nascar. $320.00

 

total - $9000.00

 

 

Head flow for the Z304 heads used on the crate 427 and the AFR’s.

 

. lift . . Z304 . . . . . . AFR 205

 

.100 . . 64 .55 . . . . . . . N/A

.200 . 135 113 . . . . . 149 126

.300 . 199 171 . . . . . 205 170

.400 . 245 200 . . . . . 260 210

.500 . 271 212 . . . . . 291 219

.550 . 277 218 . . . . . 296 223

.600 . . . . . . . . . . . . 302 227

.

Edited December 19, 2014 by barnett468

[LindenBruce 27]

I second Survival Motorsports. I conferred with Barry on selecting a cam for my 428 build. I see no reason a good 390 build should cost what you are quoting. You could easily cut that in half and still have a ton of goodies. B.

[1969_Mach1 333]

I know they have been around for a while, but I have thought 427 cubic inches from a 351W block is pushing it. Are there any negative aspects of 427 cubic inches from a 351W block? For example, piston compression height so short the wrist pins pass through the ring groove for the oil control ring, life span of the piston rings is short because the stroke is so long, the connecting rods swinging through large angles because of the long stroke.

 

I don't mean to sound negative. My engineering mind set tends to wonder if there are negative aspects to something like this.

Edited December 19, 2014 by 1969_Mach1

[barnett468 418]

I know they have been around for a while, but I have thought 427 cubic inches from a 351W block is pushing it. Are there any negative aspects of 427 cubic inches from a 351W block? For example, piston compression height so short the wrist pins pass through the ring groove for the oil control ring, life span of the piston rings is short because the stroke is so long, the connecting rods swinging through large angles because of the long stroke.

 

I don't mean to sound negative. My engineering mind set tends to wonder if there are negative aspects to something like this.

 

you do not want to use more than a 4.100 stroke crank in an old 351 windsor . . at .030" over, it is a 418 . . the new 427 crate windsor uses a 4.100 stroke but a 4.125 bore to get the 427.

 

the max stroke for a new boss 351 block is 4.250 . . i think the max stroke for a dart block is the same but it costs a little less.

 

an fe 427 bore is 4.232 x 3.784 stroke . . this is why the thing revs to 10 zillion rpm.

 

an fe 428 bore is 4.132 x 3.980 stroke . . this is why this does Not rev to 10 zillion rpm

 

.

Edited December 19, 2014 by barnett468

[sportsroof69 13]

.

That 427 crate engine is from a boss 351 windsor ford racing small block . . it is a great block but you could probably build a better one for a little less . . you could even buy any used 351 block and build it to 418 but i would not build it past 408 due to the increasingly poor rod to stroke ratio. . the later 351's are roller ready which will save you some money on lifters but the lifters won't be quite as good.

 

The set up below will be FAR better than the crate 427 and it will cost less.

 

i and others can tell you how to easily get over 500 hp with any 351 block.

 

below is just 1 option.

 

used 351 block - $150.00 - $500.00

 

machine block so pistons are around .003 below the block deck.

 

 

BOSS 351 block . Same one they use for the 427 $2050.00

 

http://www.summitracing.com/parts/fms-m6010boss351?seid=srese1&gclid=CKq8mOvk0MICFQmNaQodLoUAUw

 

 

cost to bore to proper size - $200.00

 

cost to “0†deck and square to the crank, which they do NOT do on the ford 427 crate engine $200.00

 

 

418 BIG BORE KIT - this fits original windsors only . . it will not fit a new ford or eagle block because they use a smaller crank diameter, however you can make up a kit for the new blocks for the same price . . 19 cc’s pistons but you need flat top pistons, internal balance, 4.100 stroke, 4.030 bore $2400.00 . . you can change stroke and pistons for around the same price . . this kit is for an orig windsor block which has a 3.00" main journal . . the new ford and dart blocks use a cleveland size 2.79 main.

 

http://www.summitracing.com/parts/sca-1-47510bi/overview/make/ford

 

 

if you build your own kit i might use this 4.0 stroke internal balanced, knife edged crank for the original windsors $725.00

 

http://www.summitracing.com/parts/kot-011fad400/overview/make/ford

 

 

use this one for the new blocks $725.00 . . uses .940 wide rod.

 

http://www.summitracing.com/parts/kot-011ead400/overview/make/ford

 

 

these eagle rods are nice and have doweled caps like the scats, 665 grams, 6.2 long for 2.1 crank journal, arp bolts, .940 wide $540.00

 

http://www.summitracing.com/parts/esp-6200b3dl19/overview/make/ford

 

http://www.summitracing.com/parts/esp-6200b3dl19-1

 

 

or scat lightweight I beam rods 620 grams $520.00

 

 

probe pistons for 6.2 rod, 4.0 stroke, 9.480 [69 thru 72 block] block height . . 9.5 blocks should be milled for 0 deck height to improve quench/squish distance.

 

probe pistons $465.00

 

http://www.summitracing.com/parts/pbp-12357-030/overview/make/ford

 

 

or use an eagle 6.250 rod with 4.0 stroke

 

http://www.summitracing.com/parts/esp-6250b3d2000/overview/make/ford

 

 

srp 1.23 height for 9.480 blocks 4032 alum with 1/16†rings, $525.00 . . can be used with 9,5 blocks but it is best to mill them to 0 deck to improve quench/squish distance.

 

http://www.summitracing.com/parts/srp-206057-8/overview/make/ford

 

 

mahle 1.245 height for 9.5 blocks, not early 9.480 blocks $600.00 with moly plasma rings

 

http://www.summitracing.com/parts/mle-sbf245030f06

 

 

je 1.25 height for 9.5 blocks, not early 9.480 blocks $750.00

 

http://www.summitracing.com/parts/jep-188704-8/overview/make/ford

 

 

moly plasma rings $120.00 . . not needed with complete stroker kits.

 

 

for around $1920.00, using the separate parts above, you have a killer 4.0 inch stroker rotating assy [minus bearings] that is a little better than the ford one.

 

 

AFR 205 heads $1870.00

 

http://www.summitracing.com/parts/afr-1458/overview/make/ford

 

 

Ford Racing Z304 heads on 427 . . $2200.00 . . These are MORE than the AFR heads and are NOT as good . . See flow chart below.

 

http://www.summitracing.com/parts/fms-m6049z304da

 

 

Use this cam or similar for a roller block with 1.60 rockers . . I would have it ground on a steel blank . . If you use a non roller block, have it ground on a retrofit profile for lifters with a .750 wheel $240.00 - $340.00 . . or get a custom cam from cam research, bullet cams or straub technologies.

 

http://www.lunatipower.com/Product.aspx?id=1671&gid=289

 

 

or this cam ground with a 112 lsa in steel for .750 roller wheel lifters . . use 1.65 rockers with it.

 

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=1068&sb=0

 

 

or this retrofit cam with 1.65 rockers

 

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=898&sb=0

 

 

Scorpion race series rockers - $240.00

 

Rollmaster timing chain set - $135.00 way better than the ford crate eng chain.

 

mellings oil pump and high perf drive shaft $120.00

 

high volume baffeled oil pan [optional] $250.00

 

Morel lifters - $750.00 p/n 5979 or 5879 . . you can buy other brands for less or the lower cost small wheel morels for around $550.00, tbut these are xlnt and way better than the ford crate eng lifters . . ask lunati if they sell them . . they repackage them . . if they do they might cost less from them . . confirm that they will work in the particular block you use.

 

engine balance - $200.00

 

gaskets - $100.00

 

.080" wall chromoly push rods - $80.00

 

engine assembly - $700.00

 

ATI crank damper . Way better than any other by FAR for street apps same brand used by nascar. $320.00

 

total - $9000.00

 

 

Head flow for the Z304 heads used on the crate 427 and the AFR’s.

 

. lift . . Z304 . . . . . . AFR 205

 

.100 . . 64 .55 . . . . . . . N/A

.200 . 135 113 . . . . . 149 126

.300 . 199 171 . . . . . 205 170

.400 . 245 200 . . . . . 260 210

.500 . 271 212 . . . . . 291 219

.550 . 277 218 . . . . . 296 223

.600 . . . . . . . . . . . . 302 227

.

 

I actually agree with most of this. A cast crank and I beam rods are just fine for most application. I use them in my 408 and spank it with a healthy does of nitrous. It has lots of passes with no issues. I prefer the twisted wedge heads on a stock block, and I'd use a better set of rings, such as Total Seal race rings. They cost more, but you'll have better efficiency, and efficiency = power.

[MikeStang 247]

Have less than 7k in my 408 with AFR heads and made 550hp...and had it done local.

[barnett468 418]

i like to err on the side of caution especially when making suggestions to others . . if it was my engine i could take the small risk of running cast stuff . . i have also heard of a few people breaking the cast scat cranks at 600 hp on non supercharged engines. . i dont know it their quality has gone down or if they just had a bad batch or what but the k1 crank i listed is a good forged piece and only around $200.00 more than a scat cast crank and eagle sells a forged one for $620.00.

 

the eagle rods are xlnt and maybe $250.00 more than cast ones.

 

i would not run hyper pistons in an engine like this but they may be fine if sportsroof runs them then i would use the ones he runs if you wanted, but the forged probes are only $80.00 more than kb hypers . . the mahles are 120.00 more and the srps are $145.00 more, so for only $450.00 more than a scat cast assembly, you have an absolutely unbreakable rotating assy . . i like to save money just as much as the next guy but that sounds like extremely cheap insurance to me and one could certainly spend more like 3k for a crower crank and 2k for carrillo rods that only weigh 550 grams and the $750.00 je pistons i posted.

 

as far as the block goes, the dart is $150 cheaper than the boss and is very good . . if you run an orig block i would not run a late model roller, the early blocks are stronger but typically cost around $400.00 where i live.

 

as far as the heads go, both the afr 190 11r and sfr 185 heads are better than the ford z304 heads in every way and are less money however, i don't like the trick flows mainly because you have to run dished pistons with them because they don't make large chamber ones and im a bit anal about running flat tops for good squish distance.

.

Edited December 19, 2014 by barnett468

[barnett468 418]

heres some trivia for you . . you can run a non roller 351 w engine to seven thousand rpm all day long if you simply put arp bolts in the rods and have a large radius cut on the crank when they grind it . . i would also run the ati damper no matter what you do . . i can't impress enough how much this damper does to reduce crank twist which in turn reduces the load on the main caps which are just 2 bolt cast units in all the 351 w blocks . . it also reduces vibration transmitted to the car body . m. also the large radius helps reduce the potential for crank failure and any good shop can do it . . it's not rocket science, but it might cost $40.00 more.

 

if you want to do it cheap but semi reliable one option is.

 

non roller block plus machine work around $1400.00 but get a standard bore so you can go .030" over . . the reason for this is that the farther out you bore it the weaker it gets and the hotter it will run and i would not go over .040" on a 500 plus hp stroker with one if these . . some people go .060" and have no problem but you have no bores left after .060 so if you need to bore it again you need to get another one . . the new blocks can be bored .125 over.

 

Eagle SIR 6.250 H beam rods with arp bolts $270.00 . . they are only rated to 500 hp but they should easily take more than that . . this is cheap.

 

http://www.summitracing.com/parts/esp-6250bblw/overview/make/ford

 

 

k1 crank $725.00

 

http://www.summitracing.com/parts/kot-011fad400/overview/make/ford

 

 

or eagle forged 4.0 or 4.1 stroke for orig windsor blocks only $620.00 . . that's pretty cheap

 

http://www.summitracing.com/parts/esp-435140006200/overview/make/ford

 

 

Kb hyper, standard non trick flow style pistons for 9.5 block and 6.250 rod. $390.00

 

http://www.summitracing.com/parts/uem-kb261-030/overview/make/ford

 

morel .700 wheel non billet steel body but straub recommends against this one for your app $530.00 . . you could tun them and be fine or they may break . . some people are lucky and some are not.

 

These are nice heads and they flow just a little less than the afr’s but they are still $2,000.00 which is $170.00 more than the afr's, they require longer push rods, no big deal, but also require special pistons after a certain amount of valve lift and duration and I think that with the cams I suggested, you will be cutting it pretty close . . if you use conventional style pistons . . basically, in this particular case, the afr's are a much better deal . . when it comes to 165 thru 170 cc heads the twrick flows are the best bang for the buck but the afr's aren't much more.

 

http://www.summitracing.com/parts/tfs-52616601-c03?seid=srese1&gclid=CJ7UqrHq0sICFfFaMgod0U0A2g

 

http://www.trickflow.com/search.asp?N=400098+4294951917+4294951907+4294934453+4294811538+115+4294951912&autoview=sku

Edited December 19, 2014 by barnett468

[sportsroof69 13]

I wouldn't run hypers in mine because of the nitrous. Hypers do not like to be rattled at all.

 

 

I feel safe telling anyone to run a cast crank in a pump gas, hyd roller, typical 408 build. If you break it, you did something wrong.

[MikeStang 247]

My Combo Consists of Cast Eagle Stroker Crank and Forged Eagle I-Beams with Ross Pistons and pins all packed into a 1995 351W Block from a Truck, as well as All ARP hardware, IE main cap studs instead of bolts etc....

I did opt for a Main Cap Girdle to keep things safe and I have my MSD set at 6k and have only dinged it one or 2 times but the motor made peak everything on the dyno by 5500 RPM's so why spin it above 5500...keep it under 6k and if you spit something out the bottom your did something wrong or got some bad parts.

Eagles basic stroker kit is rated to 500hp with a cast crank and I beam rods then I slapped lighter pistons and pins on it so my motor should be safe because im not making that same 550 hp with the motor in the car because I dont have 2" primary headers and im not using an HP 950 carb etc.... lol

[1969_Mach1 333]

I see this thread is mainly about building a stroker motor, which I don't have. But my 2 cents are I do agree with the posts stating to not use Hypereutectic pistons. They cannot tolerate much high pressures from detonation or nitrous (if you plan to use it), etc. I've seen the head of a Hypereutectic piston broke off from detonation. Also, if a builder recommends the KB Hypereutectic pistons, be aware those have the top ring land moved closer to the top of the piston. Because of that, you will have to run a much larger ring end gap. I used one set of those KB pistons, and after what seemed like filing thousands of miles off the piston ring's ends to obtain their recommended end gap, I thought never again.

[barnett468 418]

I see this thread is mainly about building a stroker motor, which I don't have. But my 2 cents are I do agree with the posts stating to not use Hypereutectic pistons. They cannot tolerate much high pressures from detonation or nitrous (if you plan to use it), etc. I've seen the head of a Hypereutectic piston broke off from detonation. Also, if a builder recommends the KB Hypereutectic pistons, be aware those have the top ring land moved closer to the top of the piston. Because of that, you will have to run a much larger ring end gap. I used one set of those KB pistons, and after what seemed like filing thousands of miles off the piston ring's ends to obtain their recommended end gap, I thought never again.

 

yeah, i just posted them to show that you can get forged probes for a measly $75.00 more, which is less than a paultry $5.00 more per piston, so why bother with the "hyper explosive" ones . . leave those to the "professional" ebay stroker crate engine builders.

 

 

.

Edited December 19, 2014 by barnett468

[barnett468 418]

heres the only 4.0 stroke cast crank summit sells $320.00 . . it is external balanced . . it costs me around $100.00 or more to get it internally balanced . . it does not "need" to be internally balanced but i prefer to do it on apps like this so that makes it at least $420.00 . . the eagle forged, internally balanced crank is only $165.00 more from the link below . imo, if someone is building a 500 hp plus stroker engine that they plan to keep instead of sell on ehay, and they don't want to spend an additional few dollars on a forged crank, they should not be building a 500 plus hp engine.

 

http://www.summitracing.com/parts/esp-103514000/overview/make/ford

 

http://autoplicity.com/938842-eagle-sbf-4340-forged-crank-4000in-stroke?utm_source=GoogleShopping&utm_medium=CSE&utm_content=938842NOFITMENT&utm_campaign=GSNOFITMENT&gclid=CMCP2duC08ICFRAoaQodrHoAwg

 

you don't have to do anything "wrong" to break a cast chinese crank . . first of all, there is in fact a limit to how much power any crank can take.

 

secondly, scat says if you use an external balance crank on a high hp app, the crank might break, yet they sell external balanced STROKER cranks for high horse apps, although they do suggest what they think is the proper method for balancing an externally balanced cran, an internally balanced on is simply better.

 

imo, this should be a case where simple logic prevails . . spend an additional $200.00 for a forged, internally balanced crank that will take 600 hp all day long or take a risk of grenading your brand new $6,000.00 plus engine.

 

 

The following is an excerpt from Scat.

 

External balance vs rpm.

 

RPM above 5500 is more risky on a small block Chevy than a big block Chevy, however, as RPM’s go up, the weight [meaning the external balanced balancer and flywheel] wants to leave the crank due to centrifugal force. Do not be surprised if at some point fatigue sets in and the nose comes off.

 

 

The ford 535 hp 427 crate engine is internnally balanced.

 

..

.

Edited December 19, 2014 by barnett468

[sportsroof69 13]

The cast/forged crank discussion goes a lot farther than cost. Contrary to popular belief, a forged crank will not always live longer in all applications. These 351 blocks are pretty strong, but they do flex, and there's no way around it. As the block tries to flex around a forged crank, it tends to break around the main caps. A cast crank will flex with the block. Some people are going to call this crazy, and that's fine, everyone is entitled to an opinion, but there are many many examples of this, if you know where to look.

 

I purposely put a Scat 9000 cast crank in my engine, and it's been 6.12@112 in the 1/8 @ 3380lbs, which most popular ET calculators put in the 800 hp range. It's been together for 4 years and has hundreds of hard nitrous passes on it. I don't consider it a risk, I consider the best way to build a stock block. The proof is in the pudding.....

[1969_Mach1 333]

The cast/forged crank discussion goes a lot farther than cost. Contrary to popular belief, a forged crank will not always live longer in all applications. These 351 blocks are pretty strong, but they do flex, and there's no way around it. As the block tries to flex around a forged crank, it tends to break around the main caps. A cast crank will flex with the block. Some people are going to call this crazy, and that's fine, everyone is entitled to an opinion, but there are many many examples of this, if you know where to look......

 

On one side-of-the-coin that seems reasonable. The more flexible the crankshaft, the more the forces applied to it are dampened by bending of the crank, and fewer are transmitted to the structure, in this case, this engine block. Actually, technically, maybe this is referring to an impulse. Not %100 certain without reopening an old text book but the idea is there.

 

On the other side, anything cast is more brittle than its forged counterpart. So disregarding the block, in theory, a cast crank will break before its forged counterpart.