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393w vs 408w

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I have a '74 351w block sitting in my shop that I want to build a stroker motor out of. I would reuse my current AFR Renegade 185 heads for this build. So my question is: Why would anyone build the 393 over the 408? It doesn't appear that the cost of the parts are any cheaper for the 393.
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1965 Mustang GT. 11.898 @ 113.646, all motor, three pedals
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@dennis111
At what point (stroke) does oil control get to being a problem? I haven’t done a 9.x deck so I dont know but I seem to recall guys having challenges with the big displacement stuff. Maybe it was < 4.2 cranks
 

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Dhilon, the 393 is far and away the best deal for a budget. the only CUSTOM piece you need is the crank. You can use the 351W rods you already have, they're FINE. 302 pistons are available in whatever shape you need, and they are CHEAP and easy to find. No matter WHAT you build, you'll have to balance it. I've seen dozens and dozens of the 'kits' that were supposedly balanced before they were shipped, and they are all OOB by 4-6 grams. When you have your engine's rotating assembly balanced ndividually, you can be within 1/2 a gram. And don't spend any money on H beam rods, unless they are Carillo. 99.9% of the H beam rods out there are just a clever marketing ploy. Generally, the I beam is the one to choose. LSG

Arizona, stroke is not a problem for oil control. Never was. But some of the early piston designs when strokers became popular, didn't have the oil ring grooves large enough for a support spacer. Now they do. Problem solved decades ago.
 

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And don't spend any money on H beam rods, unless they are Carillo. 99.9% of the H beam rods out there are just a clever marketing ploy. Generally, the I beam is the one to choose.
So you're saying my Scat H-beam rods are no good because they're not Carillo brand or are my rods part of that .1% ? Depending on the application, H-beam rods are a good enhancement in a performance engine with reference to strength. If they weren't, why would a large percentage of racing engines use them? Yes I-beam rods are fine in most sreet engines. But I can turn my engine to 7,500 rpm, add a supercharger (mechanical or chemical) if I want to, and I don't have to worry about my rotating assembly holding together. While I agree that most people don't need them, H-beam rods are not a marketing ploy.
 
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Max, if your H beams are NOT Carillo, then, yes, they are just a marketing ploy. If you look at the very best strongest rods available, Like from Oliver or Crower, they are I beam rods. Look at what the highest power engines available from Ford, GM, and Chrysler, all have I beams. The Carillo H was a way for Carillo to break into the market, and the engineering and shape they have is unique to them, and them alone. Any other H beam is not as strong per the weight of the rod. Most of the H beams are sold as if the H shape has some inherent advantage, it does not. Its only marketing. Sorry. LSG
 

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I haven’t done a 9.x deck so I dont know but I seem to recall guys having challenges with the big displacement stuff. Maybe it was < 4.2 cranks
As already mentioned, it's not the stroke that causes oil issues but the OD of the crank journals that can become suspect at higher RPM's. Bigger is not better when it comes to lubrication. That's why a windsor crank with the smaller Cleveland diameter mains are more desirable for drag racing.

Increased stroke has its own can of worms. In a factory 2 bolt block it (plus PRM's above 6000rpm) can lead to main cap walk. A 3.850" 393w stroke will be more stable to run to 7K than a 4.1" 427w crank will be.
 

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Max, if your H beams are NOT Carillo, then, yes, they are just a marketing ploy. If you look at the very best strongest rods available, Like from Oliver or Crower, they are I beam rods. Look at what the highest power engines available from Ford, GM, and Chrysler, all have I beams. The Carillo H was a way for Carillo to break into the market, and the engineering and shape they have is unique to them, and them alone. Any other H beam is not as strong per the weight of the rod. Most of the H beams are sold as if the H shape has some inherent advantage, it does not. Its only marketing. Sorry. LSG
Having run standard Scat H beams in an 8300rpm shifted 434w for years without a tear down, I believe its not just a marketing ploy. This build was pieced together by me and self-assembled in my garage. The H beams are typically stronger than the run of the mill I beams in a low buck scenario. I do agree that in a high dollar, no expense spared build that the lighter quality I beam would be superior. Such items would typically be used on high $$ cranks too and more than likely assembled by an expert racing machinist.
 

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Pistons are hypereutectic cast, not forged. Still reasonably priced though a big dish....
It’s fixed now, Woodchuck.

You generally need the bigger dish if you intend to run pump gas with a chamber 65cc or smaller. My combo has the small “2V” factory style piston dish, and with my 69-70 block 9.48” deck height, I’m at zero deck. It yields 11.2:1 CR with my 65cc head. You can “putt“ it around with pump premium, but I use octane boost and a non-ethanol premium mix and/or race gas if I’m going to lean on it. Which is most of the time ;)
 

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Dennis, the rpm that a rod will tolerate is much much more dicatated by how heavy are the pistons and the wrist pins, and how good are the rod bolts. I remember when Eagle rods first came out. Don Nicholson ran a set in a 460 and the Eagle rods broke on the first run. Eagle was TRYING to copy Carillo, but at a lower price point. They failed to figure it out. We have a similar situation with 'capscrew' rods. Lots of Ford guys, especially among the FE crowd, were always wanting the LeMans rods, which were, in fact capscrew design. But the REASON they were capscrew, and THE ONLY REASON, was because the smaller shoulders cleared the camshaft in the '62 and '63 StarLifter engines, which had a 4.385 crank, and were 483 inches.These rods were then ALSO used in the SOHC engines, because Ford already had the rods figured out, and they were used AGAIN in the 428SCJ. Are they stronger JUST BECAUSE they are capscrew ? No, they are aren't. I find it extremely telling that the top dollar, cost-is -no-object endurance engines, like NASCAR, have some kinda I beam rod. Not just some of them, or most of them, ALL of them.

Its the ability to use the factory steel I beams, and easily available and cheap 302 pistons, that makes the 393 stroker W engine such a good and budget friendly choice. LSG
 

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@dennis111 Did your 434W have 3" mains?

Any other H beam is not as strong per the weight of the rod. Most of the H beams are sold as if the H shape has some inherent advantage, it does not. Its only marketing.
@LSG Would you stay with I beams if using a Procharger on a 408W?
 

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Sheza, depending on WHOSE I beams are we talking about, yes. I've never recommended an H beam rod to anyone, for any application. If one is upgrading rods, get beefier I beams. I can spec an I beam strong enough to do whatever you want to do. There is this myth or aura around H beams, with folks thinking they are better, or stronger. Its false. Look up the engineering. LSG
 

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And don't spend any money on H beam rods, unless they are Carillo. 99.9% of the H beam rods out there are just a clever marketing ploy. Generally, the I beam is the one to choose. LSG
Oliver rods and Crower rods are just as good as if not better than Carillo. I use Oliver Standard light rods and Crower Series 4 rods.
 

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SS2, I would agree that Oliver and Crower are better. What I was saying is that IF one ever even considers an H beam, the Carillo is the only one to consider. But the I is always my first choice. Its a strength to weight thing. LSG
 

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OK, reality-check time on the 393 vs 408. You can't find any expert to get in your ride, drive a bit and say "this is a 408" or otherwise. Yes, there are small and specific differences, but for most here, you would never know driving one. So, pick your project goals and balance the options for the answers. Costs today for whatever parts, availability, benefits and detriments, etc.

Far more important is the package planning against project goals. The cam, induction, exhaust, vehicle weight, gearing, traction, and 101 other factors that will make or break either choice. Put your time and money there. Small pros and cons are still small, e.g., rod:stroke ratio on any of them is better than 454 BBC or Honda 1.6L, and they do famously fine, right? ;) Reality checks.

A follow-up to pistons and rods, is my 427W uses H-beams. I wanted I-beams. No, it's not because H-beams are stronger or sexier, but because they had some on the shelf that day and I was on a deadline. Balancing was more involved (and ended-up at 34 oz ;)) but any decent 6.125" rods would have served on that project. Same for pistons, as I wanted reinforced HE with thin low-tension rings to best fit the project goals, but the only option that month was heavier 4032 silicon forged, but it still fit the goals—so be it.

I have nothing against any rod or piston types, unless they don't match project goals. We spun Ford stock cast pistons to 8000+ in SS class with zero failures. They each have pros and cons. Unfortunately, some spend a lot for their stuff on assumptions, and don't want to hear the extra money wasn't a big (or perhaps any) advantage. Saying "Only H!" or "Only forged!" without referring to the project goals is defensive smoke, IMO. Let fly.
 

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Dennis, the rpm that a rod will tolerate is much much more dicatated by how heavy are the pistons and the wrist pins, and how good are the rod bolts. I remember when Eagle rods first came out. Don Nicholson ran a set in a 460 and the Eagle rods broke on the first run. Eagle was TRYING to copy Carillo, but at a lower price point. They failed to figure it out. We have a similar situation with 'capscrew' rods. Lots of Ford guys, especially among the FE crowd, were always wanting the LeMans rods, which were, in fact capscrew design. But the REASON they were capscrew, and THE ONLY REASON, was because the smaller shoulders cleared the camshaft in the '62 and '63 StarLifter engines, which had a 4.385 crank, and were 483 inches.These rods were then ALSO used in the SOHC engines, because Ford already had the rods figured out, and they were used AGAIN in the 428SCJ. Are they stronger JUST BECAUSE they are capscrew ? No, they are aren't. I find it extremely telling that the top dollar, cost-is -no-object endurance engines, like NASCAR, have some kinda I beam rod. Not just some of them, or most of them, ALL of them.

Its the ability to use the factory steel I beams, and easily available and cheap 302 pistons, that makes the 393 stroker W engine such a good and budget friendly choice. LSG
The first Google search returned this: “H-beam is a stronger design when bending stress is considered,” Davis said. “H-beam rods are more difficult to machine, so they are often more expensive. I-beam rods are easier to produce and can sometimes be lighter than H-beams. All other variables being equal, H-beam rods are the strongest design.”Sep 11, 2015

Now, I am no expert, but my research has shown that I beam rods are possibly stronger in forced induction applications, but H beam can be beneficial for high RPM use. so depending on intended usage, they both have their place.
I have read that the more common failure in a connecting rod is a failure of the tensile strength during high RPM use, which would tend to lend favor to the H beam rod design and of course the quality of the rod bolts, and this would tend to contradict your concrete observation of the I beam vs H beam debate.
Now, I do concur that Carillo rods are excellent, but can you point me to your data used to formulate the conclusions of your post : I.E. I beam is better than H beam rods and Carillo are the only good H beam rods or is this just opinion? Do you have any data on failure rate of Carillo vs Eagle vs Scat, etc.?
Asking for a friend.

Chris
 

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What was the original question again? If you are on a budget but want something more than a 351, a 393 can be both cost and performance effective by using the factory 351W rods with better bolts, who gives a #@$% about H or I beam. If you are building a stroker beyond a 393 you will have to use non-standard rods, as stated use what comes in the rotating assembly kit. If you are looking for maximum horsepower in a 351W sized block, then you need to be looking at more displacement than a 408. No one here can answer your question because we don't know your goals, wishes, budget, and the answer will vary for each person because those 3 things also vary by person. Ultimately it is your car, money, and decision. However, if you are like me, no matter what decision you make, you will think it the wrong one after all is said and done. Regardless, drive and enjoy it.
 
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