Long rod 351?

[nelzfoxes]

I am pretty much decided on building a long rod 351 win, lose or draw. Any 351 will be better than stock 302, right? I particularly like the idea of running 87 octane all the time! I just picked up gt 40 heads a couple weeks ago. Last night I hit the buyitnow button on 351m/400 connecting rods. I don't even have a block yet. I think the god of ford racing wants me to build this Daddywagon of mine because I just found out about the g303 cam! Does anyone have any first-hand experience with one of these builds?

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[Mustang-junky]

Price on stroker kits has come down a bunch. If you are going to buy/recondition rods pistons, and pay to have it balanced you may as well spend a little more and get some cubes.

There is still plenty of debate of the value of long rod combos.

408 strokers are supposed to be the best 351w stroker combos. I went with a 393 for my turbo car. I already had a nice set of stock length H-beam rods, just had to buy the crank(about $375) and a set of forged dished 302 pistons(about $475, cast or hypereutectic would be cheaper though).

Jess

[nelzfoxes]

Hey! Thanks for that! I do know there are a lot of options out there. And if I were going for maximum power I'd be all over a 408. But this is my first car project and my goals are modest. My intent is to drive this thing as much as possible. It is also curious that there is no real first hand info besides the colt 351, about a long rod 351. I figure it's worth a shot to build one and see what it does. Maybe the detractors are right. Maybe the connecting rod just connects the piston to the crank. I'd like to find out for myself.

[wvragtop]

It might be your first build but I would treat it like it was my last .then they will be no wish I woulds . I buit a 302 for my first build and wished I would have put better internals in it .then nomatter which direction I went I was covered. Just saying ,good luck and don't forget to have fun !

[PaceFever79]

If you are on a tight budget, you should just rebuild the 351/GT40 to stock with a mild cam, 4v and headers, you will end up with a nice 340ish HP street motor. The long rod thing will do nothing for your mild combination. The 393 stroker (stock block, 408 crank, stock rods and 302 pistons) should be the "next level" if you can afford the parts. But that alone will only net you maybe another 20 HP and a little more torque. A nice little gain, but it is debatable if it is worth the money given the other parts in your build. The fact is, a few extra cubes are not going to make as much of a difference sucking through small GT40 heads. I would do the 393/408 if you can afford it, but don't waste sleep if you go 351, it will still run about the same with those GT40 heads. You will mainly feel more low end torque with the 393 verses the 351 (all other parts being equal) and that can be especially useful if you are running an automatic transmission, but not so much for a manual setup.

[Ethyl Cat]

You are looking at a lot of unnecessary expense building that engine based on your want list for this powerplant. Those rods have to have the big ends narrowed and the pin ends bushed. Also it does not use a factory piston(347 pin height if I remember right).

Yes the piston is about 200 grams lighter and thrust wear will be reduced.

The rod length will help the fact that you have smaller heads by reducing the instantaneous demand of the piston on the intake stroke and pulling harder late in the stroke. But it does not make a difference with the power level you want.

Build a nice thought out standard 351W and you will be more than satisfied and have money for gas.

[n2omaverick]

build a 393! Uses 302 pistons and stock 351 rods with a 3.75 stroke crank that Scat makes for $225 with bearings..... Makes a 393, you wont be disapointed!
Long rod builds are useless, the benefits (theorys) have been dispelled over and over again! The "side load", the "piston dwell" all of it.........build what ever you want, how ever you want.........but on a budget the 393 is hands down the cheapest!

[JACook]

I believe the piston dwell benefits are real, but not at any RPM level that 351 will ever see more than once.
As for the rest of it, I believe it's been a case of misinterpreting the test results. There's likely more benefit
from the effective change in valve events vs where the pistons are than anything. And those changes can be
achieved much easier than messing around with connecting rod length.

And I agree, if you're gonna go with a 351W, the 393 is hard to beat for the price.

[Ethyl Cat]

build a 393! Uses 302 pistons and stock 351 rods with a 3.75 stroke crank that Scat makes for $225 with bearings..... Makes a 393, you wont be disapointed!
Long rod builds are useless, the benefits (theorys) have been dispelled over and over again! The "side load", the "piston dwell" all of it.........build what ever you want, how ever you want.........but on a budget the 393 is hands down the cheapest!

You can't debunk math and physics. I do like your recommendation.

[n2omaverick]

You can't debunk math and physics. I do like your recommendation.

I get the math and the physics, I bought into it all in the early 90s doing sprint car engines (Chevy) we ran the longest crower rods we could buy. The engine dyno's never reflected measurable benefits, now this I will say. The longer rods drastically effected compression height on the pistons and offered a substantial decrease in piston weight, however we were running forged steel connecting rods not aluminum, so the "bob" weight of our assemblys did not change because of the lighter "shorter" pistons.

[Ethyl Cat]

Limited sprints or outlaw?

How hard were you turning it?

Was there any noticeable difference in the cylinders during a refresh?

Did you change anything else when you switched rod length? Cam timing/ lift, compression, ignition timing

Normally longer rods work best with limited head flow and lift applications in the regular world by not putting such a demand on the runners at the beginning of the intake stroke. This allows for a little less total lift required and less aggressive lobe profiles for equivalent power. ( easier on parts)

Exotic stuff in the stratosphere of extreme rpm benefit from the dwell in overlap functions and useful cylinder pressure. (also easier on parts due to slower motion at tdc overlap and less piston speed)

I do applaud the OP on wanting to try the road less traveled. I too enjoy coming up with strange combinations of parts to see what happens.

I have an early AMC v-8 combo(7.2 rod length/3.25 stroke by the way), a long rod 302 combo that I have not seen built before and a 351w budget stroker I have not seen in the build line right now.

These are the joys of the 4 stroke cycle engine!

Steve

[horsepowerjunkie]

I agree with the rest. The money you are going to spend on modifying the rods & custom pistons, could be spent elsewhere, like better flowing heads(IMO). My first 351w build was stock crank & rods, KB hyper pistons, TW heads, Comp hydro flat tappet cam. That thing ran awsome, it's still running, 10 years later!!

[nelzfoxes]

I agree with the rest. The money you are going to spend on modifying the rods & custom pistons, could be spent elsewhere, like better flowing heads(IMO). My first 351w build was stock crank & rods, KB hyper pistons, TW heads, Comp hydro flat tappet cam. That thing ran awsome, it's still running, 10 years later!!

That sounds like an awesome engine! I especially like the fact that it's still running to this day! How mild or wild did you go? Idle quality? Stock crank means stock stroke right? H/C/I 351 for the win! I would love to hear about that engine build and what it put out and whether it was streetable or not so much.

[horsepowerjunkie]

I built it for my 16 year old son & he mostly paid for it all, so he was on a tight budget! We got a 72 Torinio for free with a 351w, bored it .030, some $200 KB hyper pistons, stock crank, stock rods w/ARP bolts, balanced. Out of the box Twisted Wedge 170's($950 new at that time), a Comp XE284 hydraulic flat tappet cam(242/246 @ .050, 541/544 lift), Vic Jr intake, 750 HP holley, MAC 1 3/4" long tubes, backed with a C4 & unknown used stall, and 3.73 gears. We orignally had it in his 83 GT with full exhaust, street/strip car. It was very easy to drive on the street & ran 11.67. We later put it in a much lighter 87 Notch & whittled the time down to 11.23 @ 118! It was an awsome engine. Sold it to a buddy who still has it in his 67 Galaxie.

[nelzfoxes]

I built it for my 16 year old son & he mostly paid for it all, so he was on a tight budget! We got a 72 Torinio for free with a 351w, bored it .030, some $200 KB hyper pistons, stock crank, stock rods w/ARP bolts, balanced. Out of the box Twisted Wedge 170's($950 new at that time), a Comp XE284 hydraulic flat tappet cam(242/246 @ .050, 541/544 lift), Vic Jr intake, 750 HP holley, MAC 1 3/4" long tubes, backed with a C4 & unknown used stall, and 3.73 gears. We orignally had it in his 83 GT with full exhaust, street/strip car. It was very easy to drive on the street & ran 11.67. We later put it in a much lighter 87 Notch & whittled the time down to 11.23 @ 118! It was an awsome engine. Sold it to a buddy who still has it in his 67 Galaxie.

Wow! That is all very encouraging! You got mid 11's out of .030 and stock stroke. Granted you're whole combination worked together to produce that power. That is good news for me about the pistons! Keith Black KB333 hypereutectic pistons are at the heart of my proposed build.

[NinoGT350]

D.S.S. Racing makes some nice stroker kits as well good luck with your build
http://www.dssracing.com/category_s/101.htm

[nelzfoxes]

Well, I have the long rod part of long rod 351 windsor. Stopped in at the machine shop to ask about what I need done to build this engine. I'll probably drop off tomorrow for disassembly, cleaning and inspection of rods including magnaflux.

[86GreenStang]

There is no replacement for displacement. It is simply easier to make more horsepower with more cubes. Long rod short rod makes no difference, it is all in the combination of parts used. Look at chevy's 302. Little cubes, little rods, small duration cam yet they got 310 hp out of 302 ci's That is more than 1 hp per cube using a small 4bbl carb. I am a ford fan, but that is impressive for a stock motor back in the day.

[86GreenStang]

Forgot to mention more cubes can effect performance negatively if you looking to do more than go in strait lines. I worked in a mustang shop for years. We got in a boss9 (429 hemi) to restore and when it was finished it was incerdible in a strait line on dry roads. Making a corner with all that weight up front made it a complete dog for anything else.

[horsepowerjunkie]

The Chevy 302 engine made an advertised 290 HP. It had a large(for a production car) solid lifter 229/237 @ .050 cam, a large 780 cfm Holley carb, and large 2.02 valve cylinder heads, plus 11:1 compression, that's why Chevy's 302 made the power it did. And the power was made at higher RPM's. My buddy had one back in the day, and I drove it often, below 4000 rpm it was a turd, but 4-7 it was awsome!!

[nelzfoxes]

I know it's kinda against the grain. I am also aware I might be taking a chance on the engine not doing much more than a stock 351 lightning motor. But at 10.5:1 compression I think it'll make a little more power. I'm looking for subtle power. The kind that you can just tool around in every day, all day. When it's 100* out. When it's 5* out. You're gonna tell me to go out and buy the coyote 5.0, and trust me if I could afford it, it would already be in there. If you are a newer mustang owner then you know you just get in push the button and go. I think many of us foxbody guys and gals go too big for a daily driver. I'm not gonna run the Daddywagon at the track. Think smooth and quiet and capable of 12's on street tires!

[xctasy]

I've done all the math and research. The Rod length is 6.58 in, and with a set of machined copper head gaskets to add 50 thou to the deck height, a set of 351m/400 rods will work with the conventional 1.1629" Australian hyper 5.6 liter Pursuit 250 piston. The rod ratio is then a 302 Chev style 1.9:1 L/R ratio in a 351W pacakge height. The 393 is a poor rod ratio engine, with 1.54:1. The 23% gain in rod ratio produces a 12% gain in specfic peak power. So the longer rods make up for the reduced capacity of a having a +30 engine of 357 cubes over 393 cubes/ It's that simple.

The 385's are supperior engines to the 335's, but the 351 is the best of the pack, and set of 351M rods fix the huge side load problem every 351C had, while improving on he 351W's 1.7:1 rod ratio with no capcity loss. In terms of any 351w, a long 6.58" rod makes 6% more power.

Do it! But don't skimp on heads, do everything to get them to flow more.

The 2002 5.0 Explorer/Mountaineer based short deck factory 342 cubic inche 5.6liter Ford Falcon T3 250 and 250 Pursuit pickups made from the last US cast OHV 5.0 Windsors. Those engines were was phased out of production from SUV destined units, with the last being sent to Australia. These Windsors were then hand assembled by Tickford Engineering and turned into the most powerful normally aspirated EFI Windsor V8 made in the world. It was stroked to 5.6 liters and boasted to 335 hp at 5250 rpm and 369 lb·ft of torque at 4000 rpm with ACL pistons and a factory long stroke 3.40" crank and 5.35" rods.

It was the old 5.0ltr to start off before Tickford stroked it. No wonder why you see alot of these older fords stroked to 347's.



Problem is the rod ratio for one is 1.5735:1, so it looses 10% of its power with a 21 % l/r ratio loss. A same spec 357 with 30 thou over pistons and the same cam, head and induction would make 385 hp at 5500 rpm, and around 395 lb-ft at 3500 rpm, with just a 75 pound weight pently.

From the often crtical LS1 Aussie forum http://www.ls1.com.au/forum/showthre...ford-T3-250kw&

From just above idle in the Ford there was a strong surge of torque that made the car very quick.
The car could trot around the suburbs using just third and fourth gears most of the time. But stir the engine up and it really started to hammer along, with performance similar to the best a current XR8 can deliver.
It was a good cruiser, too, and would be a welcome companion on any interstate jaunt, were it not for one thing: its incredible thirst.
Even driving sedately on the freeway, don't expect to use any less than about 17 to 18 US miles per gallon. Around town, especially if heavy with the accelerator, you could easily see 11 US mpg as average consumption.

The engine's other big downfall was its vibration. Possibly because they were hand-assembled, some seem smoother than others, but even the best is noisy under load and fairly coarse during hard acceleration. Of course, for many owners of high-performance cars, a bit of noise and harshness only contributes to the involvement.
Transmission choices were a five-speed manual or four-speed automatic, and, given the massive torque available, the automatic is entirely viable.
The 5.6-liter engine was made optional in Tickford's TE50, a more upmarket, Fairmont-based TS50 and in the Fairlane-derived, long-wheelbase TL50.
Unlike the XR6 and XR8 versions of the AU Falcon, you don't get the quad headlight treatment, but you do get a more restrained presentation that is still different enough to separate the cars from their non-Tickford-badged relations.

[xctasy]

See http://www.autospeed.com/cms/A_2370/article.html for details in metric. A tall deck, long rod 351W with Aussie ACL pistons should make a very easy 385 hp in EFI form with the right intake and exhast.



MINIMUM FOR 351w BEST BANG FOR BUCK,

GT40P heads, with 1.9/1.64 valves and port work mainly on the exhaust side.
1.6:1 rockers
The 4% capacity increase should bring the compression up to 10.5:1
At very least, a Crane 2031, which is a 0.513/0.529, 276/282 duration.050 inch Lift: 214 int./220 exh. With 1:7 rockers and AFR 185 or 165 heads work better Piston to valve than the stock gt40's...piston to valve cleatance is an issue with 1.7"1 rockers on a stock head.
Explorer manifold with 70mm tb, and a ford lightning 5.0 90mm MAF
balance the bottom end.
msd edis 4 ignition system
4 into 1 headers, twin 2.5" into single 3" exhaust

BEST 400 plus hp BUILD USNG JUNKED T3 ENGINE PARTS

− AFR 185cc Alloy heads- 60cc chambers, modified pedestal mounts
− Comp Cams XFI 5.0 Stroker hydraulic roller camshaft- 236/248 @ .050", 286/300 total, .579"/.579" lift
− Yella Terra 1.6 ratio adjustable Aluminium Roller Rockers
− Full ARP Head, rocker and main studs
− Full Felpro gasket set
− Isky adjustable guideplates
− Trend hardened chrom-moly pushrods
− PAC Beehive springs and Comp lightweight retainers
− Crane hydraulic lifters
− ACL Race series rings and bearings
− Rollmaster double row timing chain with nitrided gears
− Stock 351W Lightening roller block- factory bored .020" oversize, torque plate honed
− Stock T3 ACL Hypeurtectic pistons, dished and notched (9.7cc)
− Stock 351 M rods shotpeened with ARP bolts
− Stock 351W Lightening nodular iron stroker crankshaft
− Stock T3 Intake manifold
− Stock T3 82mm throttle body
− Stock T3 laser cut main girdle
− Stock T3 oil pump and sump
− Stock T3 fuel pump and fuel lines
− Bosch 43Lb injectors
− 4 into 1 ceramic coated s/steel extractors, twin hi-flow 3" cats, twin 3" stainless steel all the way with X pipe, lukey Race mufflers and twin rear resonators
− AU Edit- extensively tuned by Simon from Xtreme Ford Tuning
− retuned BluePower chip
− MSD DIS-4 ignition system
− Walbro 255lph fuel pump
− MSD Blaster 4 tower coil packs
− MSD 8.5mm Super Conductor leads
− Launch control (2 stage RPM limit)
− Ford Lightning 90mm MAF
− 100mm intake assembly and shielded custom CAI with K&N filte

The Receivers and Managers of Automotive Components Limited (Receivers and Managers Appointed) (In Liquidation) (ACL) announced on Monday, 29 April 2013 that ACL is being offered for sale. The piston are around and going cheap.

site http://catalog.acl.com.au

[Ethyl Cat]

[QUOTE=xctasy;1590913]I've done all the math and research. The 23% gain in rod ratio produces a 12% gain in specfic peak power. So the longer rods make up for the reduced capacity of a having a +30 engine of 357 cubes over 393 cubes/ It's that simple.[QUOTE=xctasy;1590913]

Increasing piston area and the length of the mechanical lever arm is a thing of the past!!

Yep, change the rods on your 400 hp engine and gain 50HP!!! YOU HEARD ME!! 50HP!! (12%)

Change the rods on your 350 HP engine and gain 40 HP!!!! (12%)

That is all you need to do!!

IT'S JUST THAT EASY!!! EVERYONE IS DOING IT!!! WHAT ARE YOU WAITING FOR!!!!??????

But wait... there's more!!!

I will apologize for this now as it is mostly tongue in cheek and absolutely not meant to be an attack on this post. The last sentence made me do it.

XCTASY, do you have any specific examples of this formula in practice? Are you saying that for a given bore and stroke I can gain from a rod length increase?

I have a combination for a 302 Ford that with the same stroke and bore I can gain 10.5% in rod ratio. By you statement, all else being the same, on a 340 hp combination I can gain approx 5.5%? (19HP)

Also, if you have the data, I would also like to see any other changes done to these engines to optimize the increase in rod length. I have always tried to find a good compromise in length as I tend to build more street engines but I have never seen these numbers before.

I eagerly await your reply

Steve

[Ourobos]

Regardless of which variant of a 351 you go with, running 302 parts (GT40 iron heads) will produce 302 power..