Posted By: BPE
Any Interest in Smallblock 3.79" Stroke - 10/29/12 01:22 AM
I have had a few people ask about the 3.79" stroke stuff and just wanted to see if there was any other interest in these combos.
Rod
Rod
Any Interest in Smallblock 3.79" Stroke
Posted By: CMcAllister
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 01:26 AM
Posted By: 1967dartgt
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 02:26 AM
Yes.
Posted By: mopar dave
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 02:29 AM
I'v been interested in the 3.79 stroke for a long time. Been told the 3.79 stroke always makes more power than the 4.00 stroker motors when the other components are kept the same. Any truth to this. My 408 will need freshening in a few years and interested in this 3.79 crank again.
Posted By: 408strokerdart
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 02:36 AM
I personally like the 3.79" stroker combos. Just seems to work well. Kind of on the edge though for bracket guys that have good heads, they just don't want to turn them that many RPM. 
Posted By: Dos Snails
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 02:45 AM
Yes!!! It's about the bigest I can use in my 9" deck.. 
Posted By: 340_Dart
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 02:46 AM
If you can make one with 2.25" mains and 2" rod journals for my Furd main R3 Rod! 
Posted By: mopar dave
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 03:08 PM
callies used to have a dragonslayer in the 3.79 stroke and i believe it had 360 mains. so,whats the verdict on 3.79 stroke,do they make more power than 4.00 stroke? rod ratio would be better and maybe less friction or side loading with the shorter stroker. anyone dyno'ed the two to see any differences?
Posted By: emarine01
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 03:53 PM
I like the 3.79 stroke on blocks that can go over 4.100 bore, on factory blocks go with more stroke
Posted By: Streetwize
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 04:15 PM
The 3.79" stroke and a 6.25" rod is a fantastic High RPM combo...when you have enough head to take full advantage of it.
For ~90% of Street/Strip or Moderate (sub 7000 RPM) Bracket cars they don't usually have enough head CFM to take advantage of the RPM; So in a lot of ways you're better off with a 4" stroke "Torque Motor", especially with an Automatic. but with good heads 4 speed or a light car I'd prefer a 3.79 all the way
For ~90% of Street/Strip or Moderate (sub 7000 RPM) Bracket cars they don't usually have enough head CFM to take advantage of the RPM; So in a lot of ways you're better off with a 4" stroke "Torque Motor", especially with an Automatic. but with good heads 4 speed or a light car I'd prefer a 3.79 all the way
Posted By: HotRodDave
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 04:18 PM
I can not believe all the people who think a shorter stroke will make more power 
I guarantee that if NASCAR let every one run a 4.185 bore and 4 inch stroke there is not one team that would keep running 3.125 or so strokes. Or if pro stock told every one they could add 1/2 inch stroke to whatever they are running that every team would run the bigger stroke. Or Indy car or sprint car or Formula 1 or...
If you are block limited like the guy with a 9 inch deck height then maybe but a factory 9.6 deck height small block can easily swallow a 4 inch stroke with little if any grinding and even a 4.25 with a little minor grinding. Then you can make a lot more power at lower RPM so your valve train can last longer and the average between TQ peak and HP peak will tend to be a lot fatter and result in a faster car.
I guarantee that if NASCAR let every one run a 4.185 bore and 4 inch stroke there is not one team that would keep running 3.125 or so strokes. Or if pro stock told every one they could add 1/2 inch stroke to whatever they are running that every team would run the bigger stroke. Or Indy car or sprint car or Formula 1 or... If you are block limited like the guy with a 9 inch deck height then maybe but a factory 9.6 deck height small block can easily swallow a 4 inch stroke with little if any grinding and even a 4.25 with a little minor grinding. Then you can make a lot more power at lower RPM so your valve train can last longer and the average between TQ peak and HP peak will tend to be a lot fatter and result in a faster car.
Posted By: Leon441
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 04:54 PM
Pro stock does not limit stroke. They limit the cubes at 500. Thats why they run the little stroke and huge bore. More power that way.
I just never understood the 3.79 stroke. 3.800" is much more common in higher end engines. If you have a low deck block 3.800 is about the limit for stroke.
If I had a tall block I would rather have 4.00" but nothing wrong with the shorter stroke if you don't have room.
Leon
I just never understood the 3.79 stroke. 3.800" is much more common in higher end engines. If you have a low deck block 3.800 is about the limit for stroke.
If I had a tall block I would rather have 4.00" but nothing wrong with the shorter stroke if you don't have room.
Leon
Posted By: HotRodDave
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 05:02 PM
NASCAR don't limit stroke either, just saying if they had the option to run longer stroke as a way to go beyond the current cube limit then they ALL would do it. Unless there is a cube limit then there is no reason to run less stroke than the maximum your block can easily handle (I am not talking compromising cam profiles or ring lands or grinding too close to water passages, just within reason)and a standard deck height SB mopar can easily handle more that a 3.79 stroke.
Posted By: RobX4406
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 05:04 PM
Having to work within a CI displacement limit has nothing to do with the choices they make in any of those series...
I bet they wouldn't mind turbochargers either.
Yeah 440 inches in a cup car would only mean about 235-250+ at places like michigan. Probably in the 1000+ hp.
I bet they wouldn't mind turbochargers either.
Yeah 440 inches in a cup car would only mean about 235-250+ at places like michigan. Probably in the 1000+ hp.
Posted By: mopar dave
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 05:17 PM
I talked to bill richardson at ram racing a while back about both cranks and which one he would choose in a small block. He liked the 3.79 over the 4.00 saying while dynoing both the 3.79 always made more power on the dyno. These were street/strip motors. Just curious if anyone here had simular info to draw a conclusion.
Posted By: HotRodDave
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 05:51 PM
Will the 3.79 make more power per cubic inch? yes, more total power no. A 3 inch stroke would also make more power per inch than a 3.79 but less overall HP and less forgiving of anything less than perfect shift timing and even harder on valve train... that has all been my experience.
Posted By: mopar dave
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 06:03 PM
When bill told the 3.79 always made more power than the 4.00 on the dyno he didnt explain how. I figured their might be better rod ratio and less side loading and less friction with the 3.79 crank and maybe thats where more power can be made over the 4.00 motor. 
Posted By: Streetwize
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 06:04 PM
@BPE I think that generally a 3.75" works better because that way with a 6.25" rod you can use the same stocking stroker piston as a common 4" stroke with a 6.123 rod in a typical 9.6 deck
Posted By: RobX4406
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 06:35 PM
Quote:
Will the 3.79 make more power per cubic inch? yes, more total power no. A 3 inch stroke would also make more power per inch than a 3.79 but less overall HP and less forgiving of anything less than perfect shift timing and even harder on valve train... that has all been my experience.
Have you tested that out?
I've seen 360's with the same cam/heads make the same peak HP as a 4" stroker. TQ was nowhere near the same nor were peak levels the same.
Those 3.79 arms flat out work well. You're talking a 20 cu in difference. Ask about the 340/360 difference, it's about the same here, not much.
Posted By: bigtimeauto
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 06:37 PM
long stroke and long rods only work on the internet 
Posted By: Plumb Wired
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 06:48 PM
I'll keep on using my 3.79" stroke cranks and Craftsman Truck W8 junk. 
Posted By: FASTFISH420
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 07:31 PM
For my combo 9.0 deck.. I run a 3.72 stroke 2.25 main with 2.0 rod journal 6 inch rod with a 4.22 bore.
Posted By: Otherlane
Re: Any Interest in Smallblock 3.79" Stroke - 10/29/12 10:10 PM
Ask bill what does he think is the best sb head,he will tell you brodix mc head
Posted By: J_BODY
Re: Any Interest in Smallblock 3.79" Stroke - 10/30/12 02:46 PM
Loved our 4" stroke W5 mill we had. Of course we require the "kiss" anology when it comes to performance engines. Not sure what the next combo will consist of, but a Ritter block is on the short list of items we'll be using.
Posted By: BPE
Re: Any Interest in Smallblock 3.79" Stroke - 10/30/12 05:14 PM
Kent is one of them that is pushing me to do the 3.79" stroke.
Rod
Rod
Posted By: joes68340s
Re: Any Interest in Smallblock 3.79" Stroke - 10/30/12 06:18 PM
Im interested in the 3.79 stroke for 340 mains. I havent checked much, but I cant find anyone selling them anywhere.
Posted By: sixpackbee
Re: Any Interest in Smallblock 3.79" Stroke - 10/30/12 06:31 PM
I am going to do a 4.185x3.79 W9 for a nasty street car. 3.79 is a more efficient way to go. I'll sacrafice a few cubes in favor of puting more power pulses down the race track.
Posted By: mopar dave
Re: Any Interest in Smallblock 3.79" Stroke - 10/31/12 05:09 AM
i'm using a 71 360 block short filled and i can't go 4.185 bore or i would use the 3.79 crank without second guess. i'm stuck with the 4" crank with my block so i'm thinking something like a 6.4" rod with a 1.250 ch mahle piston. this would give a better rod/stroke ratio(1.6) and a much lighter piston than what i'm currently using.
Posted By: dodgeboy11
Re: Any Interest in Smallblock 3.79" Stroke - 10/31/12 06:00 AM
Everything else the same, the shorter stroke will make more horsepower at a higher rpm than the longer stroke, but I would bet that add more airflow to the longer stroke and it will make more horsepower at the same higher rpm than the previous setup did with the shorter stroke. The main thing is whether or not the block can handle all the extra stress of the longer stroke.
Now the problem with nascar running a longer stroke is they would have to run larger rod and main journals to make it work. Once they did that then their bearing speed would be excessive and the engines wouldn't want to last in an endurance application at the type of rpm they are running. The other problem is packaging; they would need taller decks to get a similar rod ratio to make it a viable endurance motor for higher rpm. I'm not saying they wouldn't find a way, I'm just listing the problems that I see and why they might choose not to run a longer stroke. Of course if they chose to lower the rpm range, all of my arguments are then invalidated.
Now the problem with nascar running a longer stroke is they would have to run larger rod and main journals to make it work. Once they did that then their bearing speed would be excessive and the engines wouldn't want to last in an endurance application at the type of rpm they are running. The other problem is packaging; they would need taller decks to get a similar rod ratio to make it a viable endurance motor for higher rpm. I'm not saying they wouldn't find a way, I'm just listing the problems that I see and why they might choose not to run a longer stroke. Of course if they chose to lower the rpm range, all of my arguments are then invalidated.
Posted By: bigtimeauto
Re: Any Interest in Smallblock 3.79" Stroke - 10/31/12 02:04 PM
Quote:
Everything else the same, the shorter stroke will make more horsepower at a higher rpm than the longer stroke, but I would bet that add more airflow to the longer stroke and it will make more horsepower at the same higher rpm than the previous setup did with the shorter stroke.
well if we added more airflow for the longer stroke couldn't we just add more airflow to the shorter stroke and make more power once again? i would rather have my piston speed due to engine rpm over stroke.
I'll tke the higher rpm, biggest bore, shortest deck and just long enough stroke everyday over those out of square strokers.
Posted By: fishy340
Re: Any Interest in Smallblock 3.79" Stroke - 10/31/12 03:58 PM
Bigger cranks on a sb have there place(less rpm=less maintenance).. but on a SB more rpm/will make the power u want. If u can get a 440 and up sb to stay alive at 9000+rpm,that would be interesting to see....especally the head used to do it
Posted By: CMcAllister
Re: Any Interest in Smallblock 3.79" Stroke - 10/31/12 09:47 PM
I asked this question recently; maybe this would be a good place to ask again.
We have a MP NOS 3.79 crank in the 1053 material. What is the limit and the potential of this piece? I have an idea of using it in a drag race engine in the 650-700 HP area or in a nice street engine.
We have a MP NOS 3.79 crank in the 1053 material. What is the limit and the potential of this piece? I have an idea of using it in a drag race engine in the 650-700 HP area or in a nice street engine.
Posted By: Winchester 73
Re: Any Interest in Smallblock 3.79" Stroke - 11/01/12 04:17 AM
Quote:
Pro stock does not limit stroke. They limit the cubes at 500. Thats why they run the little stroke and huge bore. More power that way.
I just never understood the 3.79 stroke. 3.800" is much more common in higher end engines. If you have a low deck block 3.800 is about the limit for stroke.
If I had a tall block I would rather have 4.00" but nothing wrong with the shorter stroke if you don't have room.
Leon
i think youre looking at it wrong-they limit cubic inches not valve size thats why they go for huge bores-big head breating.this doesnt concern most folks building mopars becus we have a select menu of heads and cubic inches to put under them .
nascar engine builders have said that a given cubic inch limit that bore vs stroke is not worth enuff persuing and these guys fight for very little hp
Posted By: joshking440
Re: Any Interest in Smallblock 3.79" Stroke - 11/01/12 04:21 AM
Only if it has 360 Rod Journals
and a side of refried beans and salsa please....Rod..Rego
and a side of refried beans and salsa please....Rod..Rego
Posted By: Brian Hafliger
Re: Any Interest in Smallblock 3.79" Stroke - 11/01/12 05:11 AM
Quote:
I asked this question recently; maybe this would be a good place to ask again.
We have a MP NOS 3.79 crank in the 1053 material. What is the limit and the potential of this piece? I have an idea of using it in a drag race engine in the 650-700 HP area or in a nice street engine.
It will live for a long time but they have a much shorter life than 4340. I'd use it and replace it after maybe 1000 - 1200 passes.
It's all about cycles....
Posted By: cheapstreetdustr
Re: Any Interest in Smallblock 3.79" Stroke - 11/01/12 01:06 PM
there are still some classes out there that limit cubic inch in heads up racing...
or atleast the weight brake cut off is around
385"cubes..
this crank is perfect for that..and 4yrs ago i could not find a 3.79 crank to fit my needs..
during MY search..I came across a few guys looking for them also..fwiw
or atleast the weight brake cut off is around
385"cubes..
this crank is perfect for that..and 4yrs ago i could not find a 3.79 crank to fit my needs..
during MY search..I came across a few guys looking for them also..fwiw
Posted By: Dos Snails
Re: Any Interest in Smallblock 3.79" Stroke - 11/05/12 01:02 AM
How hard for a 3.75???? Better for a 9 in deck with off the shelf Cheby pistons.. 
Posted By: D-50
Re: Any Interest in Smallblock 3.79" Stroke - 11/05/12 02:22 AM
I have a 3.79 stroke crank in my 394 ci motor with 360-2 Indy heads at 10.9 to 1 compression that Brett Miller and Vic Bloomer built and it made 662 at 7300 on 93 octane fuel. I am very happy with the performance so far. I have got a lot of tuning left to do. The best I have ran so far is a 1.34 60ft,6.34 at 108 mph at 2950 lbs.I think there is still alot left in it. I am running a mechanical fuel pump and a 950 holley with no jet changes and no timing changes. I am shifting at 6800.
Posted By: DblOJoe
Re: Any Interest in Smallblock 3.79" Stroke - 11/05/12 03:28 PM
Quote:
I have a 3.79 stroke crank in my 394 ci motor with 360-2 Indy heads at 10.9 to 1 compression that Brett Miller and Vic Bloomer built and it made 662 at 7300 on 93 octane fuel. I am very happy with the performance so far. I have got a lot of tuning left to do. The best I have ran so far is a 1.34 60ft,6.34 at 108 mph at 2950 lbs.I think there is still alot left in it. I am running a mechanical fuel pump and a 950 holley with no jet changes and no timing changes. I am shifting at 6800.
Maybe I could get Vic to clone this for me...
Posted By: MIKES_DUSTER
Re: Any Interest in Smallblock 3.79" Stroke - 11/05/12 08:18 PM
Ok,Im gonna ask a stupid question for some but Im not good with math.
I have a 360,.040..How many cubes would the 3.79 crank make in my block???
I have a 360,.040..How many cubes would the 3.79 crank make in my block???
Posted By: Dunnuck Racing
Re: Any Interest in Smallblock 3.79" Stroke - 11/05/12 08:57 PM
388.671
Keith
Keith
Posted By: HotRodDave
Re: Any Interest in Smallblock 3.79" Stroke - 11/05/12 11:06 PM
Been trying to think of a good reason for someone NOT to go 4+ inch stroker... if it fits a 360 block and is cheap enough it could be used with a low compression stock 360 piston and stock rods for a cheap compression and cubic inch bump
Posted By: emarine01
Re: Any Interest in Smallblock 3.79" Stroke - 11/06/12 01:41 AM
Quote:Ya cant use a stock piston in a 4 inch deal and the stock rod would be a weak link due to the piston speed on 4+ inch engines
Been trying to think of a good reason for someone NOT to go 4+ inch stroker... if it fits a 360 block and is cheap enough it could be used with a low compression stock 360 piston and stock rods for a cheap compression and cubic inch bump
Posted By: 340_Dart
Re: Any Interest in Smallblock 3.79" Stroke - 11/06/12 01:57 AM
Quote:Quote:Ya cant use a stock piston in a 4 inch deal and the stock rod would be a weak link due to the piston speed on 4+ inch engines
Been trying to think of a good reason for someone NOT to go 4+ inch stroker... if it fits a 360 block and is cheap enough it could be used with a low compression stock 360 piston and stock rods for a cheap compression and cubic inch bump
Why would you want to use stock rods or pistons with either crank? The increased piston speed and stress on the rods would tear them apart.
Posted By: HotRodDave
Re: Any Interest in Smallblock 3.79" Stroke - 11/06/12 07:34 PM
Quote:Quote:Quote:Ya cant use a stock piston in a 4 inch deal and the stock rod would be a weak link due to the piston speed on 4+ inch engines
Been trying to think of a good reason for someone NOT to go 4+ inch stroker... if it fits a 360 block and is cheap enough it could be used with a low compression stock 360 piston and stock rods for a cheap compression and cubic inch bump
Why would you want to use stock rods or pistons with either crank? The increased piston speed and stress on the rods would tear them apart.
BUDGET.
There are plenty of people running stock rods in mild 4 inch stroke engines, the light weight pistons help alleviate a lot of the stress from the longer stroke. I am not saying this should be an all out build running stock rods/pistons, just a way to build some power on the cheap. A 3.79 stroke does not add much cubes over a 3.58 but on a budget build it could add a few cubes and a little compression and not over stress the stock parts (stock SB mopar rods are pretty tough, even the stock cast pistons are pretty robust as far as cast pistons go). You would not want to slap W9s on that kind of short block but some warmed up J heads could really benefit on a low budget street/strip car, because like it or not more people are just running some sort of stock head not even W2s or Eddys.
Posted By: emarine01
Re: Any Interest in Smallblock 3.79" Stroke - 11/06/12 08:43 PM
Quote:A stock piston compression hight wont work on a 4 inch stroke, A 3.79 stroke comes closerQuote:Quote:Quote:Ya cant use a stock piston in a 4 inch deal and the stock rod would be a weak link due to the piston speed on 4+ inch engines
Been trying to think of a good reason for someone NOT to go 4+ inch stroker... if it fits a 360 block and is cheap enough it could be used with a low compression stock 360 piston and stock rods for a cheap compression and cubic inch bump
Why would you want to use stock rods or pistons with either crank? The increased piston speed and stress on the rods would tear them apart.
BUDGET.
There are plenty of people running stock rods in mild 4 inch stroke engines, the light weight pistons help alleviate a lot of the stress from the longer stroke. I am not saying this should be an all out build running stock rods/pistons, just a way to build some power on the cheap. A 3.79 stroke does not add much cubes over a 3.58 but on a budget build it could add a few cubes and a little compression and not over stress the stock parts (stock SB mopar rods are pretty tough, even the stock cast pistons are pretty robust as far as cast pistons go). You would not want to slap W9s on that kind of short block but some warmed up J heads could really benefit on a low budget street/strip car, because like it or not more people are just running some sort of stock head not even W2s or Eddys.
Posted By: HotRodDave
Re: Any Interest in Smallblock 3.79" Stroke - 11/06/12 10:40 PM
Quote:Quote:A stock piston compression hight wont work on a 4 inch stroke, A 3.79 stroke comes closerQuote:Quote:Quote:Ya cant use a stock piston in a 4 inch deal and the stock rod would be a weak link due to the piston speed on 4+ inch engines
Been trying to think of a good reason for someone NOT to go 4+ inch stroker... if it fits a 360 block and is cheap enough it could be used with a low compression stock 360 piston and stock rods for a cheap compression and cubic inch bump
Why would you want to use stock rods or pistons with either crank? The increased piston speed and stress on the rods would tear them apart.
BUDGET.
There are plenty of people running stock rods in mild 4 inch stroke engines, the light weight pistons help alleviate a lot of the stress from the longer stroke. I am not saying this should be an all out build running stock rods/pistons, just a way to build some power on the cheap. A 3.79 stroke does not add much cubes over a 3.58 but on a budget build it could add a few cubes and a little compression and not over stress the stock parts (stock SB mopar rods are pretty tough, even the stock cast pistons are pretty robust as far as cast pistons go). You would not want to slap W9s on that kind of short block but some warmed up J heads could really benefit on a low budget street/strip car, because like it or not more people are just running some sort of stock head not even W2s or Eddys.
I guess I was not clear, I know a 4 inch stroke can not use a stock piston, I was just pointing out a way to use the 3.79 stroke crank in a budget fashion as a good reason not to use the 4 incher. With the 4 inch you can not use $100 stock replacement pistons but the 3.79 you could.
Posted By: Dos Snails
Re: Any Interest in Smallblock 3.79" Stroke - 11/07/12 01:08 AM
How about that 3.75?