Ford vs Dart Block

[Gizmosrcool]

What blocks are folks using for SBF 347?

I like the Dart. Pair with AFR or Trick Flow heads and a Sniper EFI and billet pulleys. Snazzy sexy in the engine bay. But I don’t like the premium bump in $. The problem with the dart is id end up throwing more and more at it. Because I can then and then really going overboard on the $$. That’s me chasing shiny objects again.

I know I can get a nice 400-450HP out of a ford block 347 with good alum heads and proper cam. Probably more power than I need anyway and will light up the tires in most gears and easily get me into trouble.

Does the Dart block get me anything over a Ford block if I’m looking for a solid 450HP?

Thx. Tom aka Gizmo

[edwardb]

Assume you're talking about the SHP iron block. In round numbers a $1K add to a build over a stock block. What do you get? You will get marginally more power because it's stiffer. Plus 4-bolt mains on the center three. Cylinders that are extended for the longer stroke of the stroker. 1/2-inch stud head bolts. But the main thing? An engine that doesn't break down the middle like any stock block has the potential to do north of 400 HP. I know, lots of guys run them with even more power and claim never a problem. But also plenty that know first hand they break. My #7750 build was a DART 347 with a short block from Fordstrokers. He said the SHP will hold together at 900+ HP. Well known and long time SBF builder who won't do stock blocks any more. Availability has something to do with it. Longevity the rest.

This was mine. A thing of beauty. Drove it three flawless seasons, and still going strong with its new owner in NY.

https://hosting.photobucket.com/albums/ab234/edwardb123/Factory%20Five%20Mark%204%20Roadster%20Build/Engine/.highres/IMG_2125_zps2a587ff4.jpg (https://app.photobucket.com/u/edwardb123/p/2542b463-9b5a-4593-a2a4-42f1ae9f6e1d)

[Fman]

What blocks are folks using for SBF 347?

I like the Dart. Pair with AFR or Trick Flow heads and a Sniper EFI and billet pulleys. Snazzy sexy in the engine bay. But I don’t like the premium bump in $. The problem with the dart is id end up throwing more and more at it. Because I can then and then really going overboard on the $$. That’s me chasing shiny objects again.

I know I can get a nice 400-450HP out of a ford block 347 with good alum heads and proper cam. Probably more power than I need anyway and will light up the tires in most gears and easily get me into trouble.

Does the Dart block get me anything over a Ford block if I’m looking for a solid 450HP?

Thx. Tom aka Gizmo

I have also been asking the same question to three different reputable builders, all of them have told me they do not use a Dart block for the 347 only the 427 build.

This is a direct response I got back from Blueprint engines...

"We refer to the 347 block as “seasoned”. using an aftermarket block at this power level would only increase the cost of the engine, with no real benefits. We take a 302 block, test and inspect it numerous times/ways, and we only use the bare block and main caps, once it passes all those steps. It’s a true performance built engine with all new internal components.

You’d probably be surprised to know the oem blocks have less manufacturing issues/inconsistencies than aftermarkets.

On something like a 427 at 500 hp, its worth it. for a 347, its simply more that adequate, and a nice cost saver to stick with an oem casting."

Hopefully this helps answer some of your question. I have been doing research on different engines for the past month now, it has really been a good learning experience to find out about all the different options available out there. I was dead set on a 427 but after talking to numerous owners and builders I think the 347 will be a better fit for what I am trying to get out this car. Drivability, reliability and how it looks in the jewelry box are top items on the list. I really enjoy looking at all the different engine compartments in these cars and how everyone customizes to there own liking.

[jrcuz]

I have a Dart 347 built by Mike Forte it puts out 360 hp. I don't have any time but go karting on it so no hwy time yet. In talking to Mike he said that he uses only Dart blocks for his 347 builds due mainly to the reasons edwardb states above. One thing I will say the motor mounts that FFR sends with the kit need to be massaged to work with the Dart block beacuse there is webbing cast into the block around the engine mount locations. I believe Mike offers engine mounts that are made for the Dart blocks.
JR

[frankb]

Take Edwardb's advice above. While $1K seems like a big increase now, compared to replacing the entire engine in the future due to a broken block, it's cheap insurance!

[edwardb]

Make sure you're comparing apples to apples. Blueprint (and others...) is a good choice and represents good value. A dyno'd 347 for less than $6K is attractive. But even the best Blueprint 347 is rated at 415 HP. Certainly more than adequate for these care, but south of the 450 HP stated goal. Once you start getting into that HP range, and higher, is where things start breaking. Once you start down the higher end path, e.g. forged vs. cast crank, AFR heads, Edelbrock intake, even the 1/2-inch head studs if you use ARP, the costs go up significantly. I know from experience. Just depends on what you want. But for me, if you're going to that length on everything else, use the DART block.

For the record, a small block 427 requires an aftermarket block. 351 stock blocks typically are limited to 408 just because there isn't enough metal.

[David Williamson]

I also went through this process selecting the engine for my Coupe. I wanted the lower deck height of a 302 based block to fit the lower hood in the coupe. The choice was stock block 347, Dart or Ford Boss. After talking with several of the builders here I went with a Dart 363 engine. Power is in the mid 400's, I know it will stay together and not much extra cost.
David W

[TBull]

I ran a supercharged 308 at 450 RWHP in a stock block. Like EdwardB mention, I was also always nervous, even with a girdle on it and head and main studs. In my new car, I never wanted to worry about that any more so I went Dart. It also gives you more options. There are multiple ways to make the 347. The standard way or the Big Bore way. With the Dart you can pair pistons for a 363 @ 4.125 with the 331 Crank and rods for a 347 combo with what I feel is a better geometry, a shorter faster stroke and you can supercharge it as I'm going to do. Paired with AFR heads or Trick-Flo heads and you have a winning combo at whatever HP target you might have for your car.

[scottiec]

Go with the DART. you can ask the two factory blocks sitting in my basement why they are there LOL. But honestly, there is no reason not to do the 363 if you are going to do the DART block. That is what I have and it is a nasty small block. Going with the 363 increases the bore by .125, which helps unshroud the exhaust valve.

[Quincy]

I am not sure what engine takes more room in the engine bay.


Is there a difference?

[GoDadGo]

I am not sure what engine takes more room in the engine bay.


Is there a difference?

The short deck (8.20" Deck Height) Dart SHP block is no bigger than a Ford 260, 289 or 302.
You are just increasing the bore and stroke.

302 CID 5.0 LTR > 4.000" Bore & 3.00" Stroke
363 CID 6.0 LTR > 4.125" Bore & 3.40" Stroke

A tall deck (9.50ish" Deck Height) 351 Windsor

351 CID 5.8 LTR > 4.000" Bore & 3.50 Stroke
427 CID 7.0 LTR > 4.125" Bore & 4.00 Stroke

Link To Dart's Ford Short Block Assemblies:

http://dartheads.com/dart-product/shp-short-blocks-sbf/

Reference Info From Wikipedia:
NOTE: The block underwent some changes since its inception. In 1971, deck height was extended from 9.480 in to 9.503 in (casting D1AE-6015-DA) to lower the compression ratio to reduce NOx emissions without the need to change piston or cylinder-head design.

[Bob Cowan]

For the record, a small block 427 requires an aftermarket block. 351 stock blocks typically are limited to 408 just because there isn't enough metal.

Mostly true. The early 351W blocks - 1969, 1970 - can safely be bored out to make a 427. There used to be a lot of those blocks around. Now they're kinda rare.

I agree with everything said above. I like the Dart block, and would certainly use it again.

One added benefit not mentioned, it's easier to fix. This happened to my dart block 427 at the race track. Because it was a dart block, I had it running again in a week. If it had been a stock block 408, I would be scrounging for another block and then having it checked and machined, which could take a month or more.

https://i.imgur.com/CV8DdWI.jpg

[SDhemmings]

Mine is 1995 351w roller block stroked to a 408w and is at around 483hp at the flywheel. Had it professionally built locally by a race shop, fits in nicely, fills out the engine bay with enough room to work.

[SDhemmings]

Also should mention that my 408w stock block will only be street driven, if i am on a track it would be once in a year if at all so it won't see the extreme's seen on the track. My Engine builders very first question was "What will you be using the motor for?" very important to understand that.

[GoDadGo]

Assume you're talking about the SHP iron block. In round numbers a $1K add to a build over a stock block. What do you get? You will get marginally more power because it's stiffer. Plus 4-bolt mains on the center three. Cylinders that are extended for the longer stroke of the stroker. 1/2-inch stud head bolts. But the main thing? An engine that doesn't break down the middle like any stock block has the potential to do north of 400 HP. I know, lots of guys run them with even more power and claim never a problem. But also plenty that know first hand they break. My #7750 build was a DART 347 with a short block from Fordstrokers. He said the SHP will hold together at 900+ HP. Well known and long time SBF builder who won't do stock blocks any more. Availability has something to do with. Longevity the rest.

This was mine. A thing of beauty. Drove it three flawless seasons, and still going strong with its new owner in NY.

https://hosting.photobucket.com/albums/ab234/edwardb123/Factory%20Five%20Mark%204%20Roadster%20Build/Engine/.highres/IMG_2125_zps2a587ff4.jpg (https://app.photobucket.com/u/edwardb123/p/2542b463-9b5a-4593-a2a4-42f1ae9f6e1d)

Plus The Dart SHP Blocks Have Priority Main Bearing Oiling!

[Robodent]

Thanks for all the great info guys. I bought a dart 347 from forte not knowing much about it other than it’s a four bolt main and it costs more. My engine dyno’d at 420 yea maybe over kill to have a dart block but I have the peace of mind I have something rock solid. Rob

[RBachman]

Thanks for all the great info guys. I bought a dart 347 from forte not knowing much about it other than it’s a four bolt main and it costs more. My engine dyno’d at 420 yea maybe over kill to have a dart block but I have the peace of mind I have something rock solid. Rob

Dittos on mine (and also a 420 dyno) with the 347 Dart Block. I learned a lot chatting with Mike as well. Great guy and enthusiast! (Heck of an engineer also!)

[Gizmosrcool]

This turned into the Dart fan club. Love it. Great information and it is appreciated. The only thing I have not seen is the $1k bump that Edwardb indicated. I think it’s because they are not normally apples to apples comparison. BluePrint has their own heads and they are $500/each compared to $1k/each for AFR or Trick Flow. Ditto with rockers. Blueprint are stockers and most Dart builders will use a nice billet piece. Do that for most things and the Dart build engine can easily be $2k-$4k more.

I guess if I am ok with 350-400HP and don’t ride it hard then a stock block is ok. I do like one of the ATK long blocks. It has PRO1 heads and brand name parts and 410-450HP. But if I want a solid 450HP and I may crank on it then the dart block is worth the investment.

Thx again for all the feedback. Tom aka Gizmo

[edwardb]

The only thing I have not seen is the $1k bump that Edwardb indicated...

That was in reference to the block only. Very roughly the difference between a machined and prepped stock block and the DART SHP. At least when I put mine together a few years ago. Agreed, a DART build often has overall higher end parts as you said, and I also said in my second post. My DART 347 had Scat forged crank and rods, Wiseco forged pistons, custom ground billet cam, AFR heads, Quick Fuel double pumper carb, etc. etc. Not cheap. :p

[GoDadGo]

That was in reference to the block only. Very roughly the difference between a machined and prepped stock block and the DART SHP. At least when I put mine together a few years ago. Agreed, a DART build often has overall higher end parts as you said, and I also said in my second post. My DART 347 had Scat forged crank and rods, Wiseco forged pistons, custom ground billet cam, AFR heads, Quick Fuel double pumper carb, etc. etc. Not Cheap. :p

I too used a Dart Block with a few nice upgrades.

1. 383 Small Block Dart 10-1 Somewhat Pump Gas Friendly Compression Ratio!
2. Eagle Internally Balanced Rotating Assembly With 6" H-Beam Rods With Floating Forged Mahle Flat Tops.
3. Dart Iron Eagle 215 CC Heads with 2.05 Intake & 1.60 Exhaust Valves.
4. Harland Sharp Roller Rockers & Other Go Fast Goodies.
5. Comp Cam Extreme Energy 288 Hydraulic Roller Tappet Cam
6. Edelbrock AVS 800 Feeding A Weiand 7530 Team-G Single Plane Manifold.

Even though I'm the Dark Horse in the race, my Dark Dart Chevy was Not Cheap either.

[CobraKan]

I am a new guy to the FF Roadster family, mine should be in my garage mid April so I have lots of time to think (that can be bad). I won't need a motor for a while but looking around 350 to 400ish horse power and the 347 looks like a good choice using the 302 base small block but I don't see anything about the 351 Windsor. Old tech, hard to find? Like the Dart and looked at Blueprint. Help
John

[GoDadGo]

I am a new guy to the FF Roadster family, mine should be in my garage mid April so I have lots of time to think (that can be bad). I won't need a motor for a while but looking around 350 to 400ish horse power and the 347 looks like a good choice using the 302 base small block but I don't see anything about the 351 Windsor. Old tech, hard to find? Like the Dart and looked at Blueprint. Help
John

Ford quit producing the Push Rod V8 Engines a quite few years back, but after market manufacturers like Dart now are making upgraded versions.
If you come across a good Ford 351 Windsor block then you can stroke it to 3.75, 3.85 all the way out to 4.00, but the block can only go up to about a 4.060 bore.

The Dart blocks (Tall & Short Decks) are a Siamese Type which can be pushed from 4.125 bore all with way out to 4.165.

The short deck blocks are very popular as are the tall; however, most folks that used the tall deck typically stroke them to create the 427 displacement.
That combination is a 4.125 bore with a huge 4.00 stroke so it is a toque monster which revs well in spite of the very long throws.
Most folks go with the popular 347 and 363 displacement using Short Deck Dart Block which will produced the kind of power that you are looking for.

302 = 4.000 bore / 3.00 Stroke
347 = 4.000 bore / 3.40 Stroke
363 = 4.125 bore / 3.40 Stroke

You can check out this link that I posted the other day to get an idea as to what different combinations can create:

https://thefactoryfiveforum.com/showthread.php?35073-4-000-quot-amp-4-125-quot-Bore-vs-Stroke-Combinations

As for me, I'm running a 383 which has a 4.030 bore with a 3.75 stroke, but my block can be punched all the way out to 4.165 since it was made by Dart.
It runs very cool because I've got cylinder walls that are stupid thick so I suspect a 347 based on a Dart Block would do the same.

Hope This Helps Everyone Interested In This Engine Thread!

[NAZ]

This turned into the Dart fan club. Love it. Great information and it is appreciated. The only thing I have not seen is the $1k bump that Edwardb indicated. I think it’s because they are not normally apples to apples comparison. BluePrint has their own heads and they are $500/each compared to $1k/each for AFR or Trick Flow. Ditto with rockers. Blueprint are stockers and most Dart builders will use a nice billet piece. Do that for most things and the Dart build engine can easily be $2k-$4k more.

I guess if I am ok with 350-400HP and don’t ride it hard then a stock block is ok. I do like one of the ATK long blocks. It has PRO1 heads and brand name parts and 410-450HP. But if I want a solid 450HP and I may crank on it then the dart block is worth the investment.

Thx again for all the feedback. Tom aka Gizmo


I would suggest you steer clear of ATK products. Also, when considering what engine to use and what block, think about how you might want to upgrade in the future. I know, everyone always says 350, 400, 450, etc HP is enough but if you're a true hot rodder it's never enough. So why limit yourself for future improvements?

I'm of the opinion that if you smoke the tires in any gear, the problem is not under the hood it's at the rear of the car. Don't blame power for loss of traction.

[rich grsc]

I would suggest you steer clear of ATK products. Also, when considering what engine to use and what block, think about how you might want to upgrade in the future. I know, everyone always says 350, 400, 450, etc HP is enough but if you're a true hot rodder it's never enough. So why limit yourself for future improvements?

I'm of the opinion that if you smoke the tires in any gear, the problem is not under the hood it's at the rear of the car. Don't blame power for loss of traction.

I always thought that was lack of proper control of #1 pedal. Often intensional. :rolleyes:

[TrevorP]

I cracked the stock block in half. It had about 500hp. I went for a while before it blew. Since then, I've had the boss block 347 and a Dart SHP block 363. The boss was great until I dropped a valve and it cracked one of the shirts. The Dart SHP has been bullet proof so far. It is heavier though, keep that in mind. I wouldn't spend the extra cash unless you are pushing over 400hp.

[Murd]

What do you want to do with the car? Any reason you’re putting those power numbers out there?
Not just the block that will cost you more, chasing 450 instead of say 350 will cost you a lot more too.

[CobraKan]

Again I am new to this game and find many engine builders, so I ask why do you suggest to steer clear of ATK?

[NAZ]

Again I am new to this game and find many engine builders, so I ask why do you suggest to steer clear of ATK?

I've always built my engines to my specs and using my go-to machine shops. Been doing this a long time and have the formal training and experience to know what it takes to build a solid reliable performance engine. But I purchased one of their crate engines as the cost was attractive. I found their workmanship to be substandard. Don't waste your $$ on ATK. Want a garden variety crate engine at a fair price, look at Blueprint. Want a real high performance engine, go to Shafiroff or one of the other race engine builders, they make pump gas street engines too.

Want to see a Dart Little M block build, click on the link below. With a 10.5 - 11.0 CR this would be a very fun pump gas street engine. And even with 800HP, I can stomp on the loud pedal and there is no drama or smoking tires, just plant you in the seat acceleration. So it is possible to run more than 450 HP (or some other limit pulled out of the air) in a light car without smoking the tires in every gear. You just have to set the car up to handle it.

[Avalanche325]

I'm of the opinion that if you smoke the tires in any gear, the problem is not under the hood it's at the rear of the car. Don't blame power for loss of traction.

You're just begging for my tire rant again, aren't you?

Here is something to consider. Are you easy or hard on equipment? Stock blocks don't usually break until they are pushing 600hp, not counting boost or juice. That is from a LOT of reading, I have never blown one up myself. I am not an equipment abuser even though I run my car hard. I have my rev limiter (you want one in a Cobra) set at 6200. I am sure my build would take more, but I'm not a run until I float the valves kind of guy. Some guys can break an anvil.

At 500hp or lower I don't see a real *need* for an aftermarket block unless you are going to twist it way up. Once something is strong enough, everything extra is more weight and money. That being said, good blocks are getting harder to come by. I have a 500hp 347 stock block and I regularly autocross and track.

Now that being said, looking back, I would probably do a Dart block and go out to 363. The extra money would long be a thing of the past and I wouldn't have that occasional thought when my rev limiter is kicking in.

I used FordStrokers. They have a good reputation and have an option where they do all of the machine work and you do your own assembly. They no longer do stock blocks for the lack of supply reason.

[Dwight]

I will agreed with Avalanche325
500 or less on a street motor, stock block will do.

I put 20,000 miles on a 500 fwhp EFI stock block in my Cobra. Not a problem.
Last spring I bought a Dart 363 block and was going to swap out the stock block 347 in my GT 40 but changed my mind. To much work for me at this time.
I do have the Dart block for sale. All the machine work in completed and ready to drop in rotating assembly.
Dwight

[Avalanche325]

Bob,

What was the root cause of that destroyed piston? Valve train or actual piston failure?

Amazing how good that bore looks with half a piston.

[BluePrintEngines]

Hey Guys,

Since i was quoted above, and BluePrint mentioned also, I figure I'll weigh in.

Our packages are setup at certain HP levels, for good reason. We want our engines to live forever, and our customers to be happy with them.

https://factoryfiveengines.com/ is where you'll find our FFR 306, 347's and 427's all.

When asked about using aftermarket block vs OE, its important to take power goal into consideration, and understand what that goal takes in building a longevity derived hot street engine.

When someone wants to "go big", and starts talking 500+ hp out of a 347...thats a race engine you're streeting, not a street engine you're racing.

410 hp from a 347 is more than adequate for a FFR, and if you want more, we have 427's.

For our purposes, Building a 410 hp 347, and using an aftermarket block, doesn't accomplished much other than spending/charging more money.

now a hot 363, or 427, yup, aftermarket it is. mainly for bore, but of course hp also.

I'm here to help and answer questions any time.

PS all of our factory five edition, aluminum headed engines use aluminum roller rockers. Irrelevant to the topic, but saw it incorrectly stated that we use stockers.

Johnny@BluePrintEngines.com

[Bob Cowan]

Bob,

What was the root cause of that destroyed piston? Valve train or actual piston failure?

Amazing how good that bore looks with half a piston.


Dropped a valve. Destroyed the head.

[Gizmosrcool]

What do you want to do with the car? Any reason you’re putting those power numbers out there?
Not just the block that will cost you more, chasing 450 instead of say 350 will cost you a lot more too.
Cruising, power cruise, drag racing & I love drag racing, and I’d like to try autocross. I picked 450 because it seemed pretty easy to obtain. Anything north of that and yes it would be hard on the block. It seems to be a consensus that 400 HP is ok for stock block. More go with Dart. Or go with Dart if u want the best and have the cash. Everyone is putting up very good info.

[NAZ]

Gizmosrcool, if you want to run your car at the drags I suggest you study the NHRA rules before getting too far along on planning your build. FFR cars are a challenge to make them NHRA legal, especially the Roadster. All NHRA associated tracks are supposed to follow NHRA rules for all their drag racing events even the Friday Night run what you brung type (not sayin' they do, but that NHRA requires it) so it's a good idea to check out the rule book before spending $$ on your build.



http://www.nhraracer.com/ (https://nationaldragster.s3.amazonaws.com/Rulebooks/2020_NHRA_Rulebook_11_01/page_1.html)

[Gizmosrcool]

Gizmosrcool, if you want to run your car at the drags I suggest you study the NHRA rules before getting too far along on planning your build. FFR cars are a challenge to make them NHRA legal, especially the Roadster. All NHRA associated tracks are supposed to follow NHRA rules for all their drag racing events even the Friday Night run what you brung type (not sayin' they do, but that NHRA requires it) so it's a good idea to check out the rule book before spending $$ on your build.



http://www.nhraracer.com/ (https://nationaldragster.s3.amazonaws.com/Rulebooks/2020_NHRA_Rulebook_11_01/page_1.html)

Hi NAZ. Good idea and I’m on it. My track is IHRA. I’ll have a good SFI bellhousing, balancer, safety loop for the driveshaft, certified belts, battery cutoff switch, and I’ll also have a manual fire extinguisher which I like the looks of in the car anyway. I’ll will not run fast enough to require engine diapers or anything crazy. Just fast enough to put a sticky set of tires on it and run brackets or test and tune nights. The same setup should get me into most autocross places. Add a good helmet and i am good to go. I have lots of motorcycle helmets and a really good full face one which they accept. Bring on the burnouts!

Cheers. Tom aka Gizmo

[AdamIsAdam]

347 = 4.000 bore / 3.40 Stroke
Vs
347 = 4.125 bore / 3.25 Stroke
?

What's the difference? Why do one setup over another?
And how do the two differ in terms of engine characteristics?

[Sigurd]

347 = 4.000 bore / 3.40 Stroke
Vs
347 = 4.125 bore / 3.25 Stroke
?

What's the difference? Why do one setup over another?
And how do the two differ in terms of engine characteristics?

Longer stroke = more torque
Larger bore = more rpm

[NAZ]

Longer stroke = more torque
Larger bore = more rpm

While there is some truth to this simple statement, there is far more to it than that. Larger bore tends to unshroud the intake valve which can help flow. Shorter stroke decreases piston speed which allows higher RPM before reaching the limit of strength of reciprocating components such as rods. Shorter stroke provides more rotating clearance to the block and the cam. Shorter stroke allows for a longer rod for a given compression height. Longer rods have many advantages: http://victorylibrary.com/mopar/rod-tech-c.htm

As they say, choose wisely. The way you configure your engine should be based on what your going to do with it. A street car has to operate in a much more varied environment than a race car so there will be way more trade-offs than a purpose built race engine. Everything is a compromise. Educate yourself and you will make better choices.