FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: 427HISS on July 11, 2017, 12:17:30 PM
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With either the side oiler or 428FE, what is the largest bore and cubes can a block FE be ?
I'm getting mixed numbers from several people. Some even say that 0.30 is a risk ?
I want over 600 HP & TQ.
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I've gone as far as 4.39" with an aftermarket block and no special machining operations. With my custom Shelby block I spread the bore spacing to 4.700" and went to a 4.505" bore. On factory 427 blocks I've got one that is 0.060" over with no problems, and I also have a 0.040" over 428 block. Both of these were dyno mules featured in my book. I also know at least two folks with a 0.060" over 428. I'd be reluctant to go past 0.060" over on most factory blocks, and it would be safer to stay at 0.030" to 0.040" over. A sonic check is advisable in any case, with a factory block.
As far as cubic inches, my SOHC is 585" with the spread bore block and a 4.6" stroke. Also, I know of one guy who put a 4.75" stroke in an SOHC. However, the SOHC doesn't have cam lobes for the rods to run into, so the big stroke is possible. I have run a 4.5" stroke with some clearancing of the rods on a wedge motor, but this is also limited by size of the cam lobes. Practically speaking, a 4.375" stroke is probably the biggest you can fit into a wedge FE.
Hope that helps - Jay
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Jay, do you know what was necessary to fit the 4.75 stroke in the block? I'm assuming it was a Shelby block?
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Why chase max bore and stroke to attain 600hp?
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Why chase max bore and stroke to attain 600hp?
!!!
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The 4.75 was one of my builds.
It was a Pond block.
Crank is a Scat billet.
Rods were custom made steel from R&R in Illinois in an odd length..
It is a Cammer - so no cam clearance issues. But virtually every surface of the block interior needed "loving", and the counterweights of the crank ended up needing a severe amount of contouring to clear the piston pin bosses.
I don't think I would want to do it again....
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Why chase max bore and stroke to attain 600hp?
Don't know what the OP's intentions were, but one reason I can think of is that a big CI engine could act very tame at 600hp. You know, speak softly and carry a giant freakin club :)
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I think the OP was just trying to get some clarification on what is possible in terms of cubes. And I think Barry meant to say 4.75" for the stroke on his SOHC engine, not 4.375"...
On my engine with the 4.6" stroke, I used a 6.700" rod, a Crower crank, and a Shelby block. I bought the sleeves long, so that they could be notched for the reciprocating assembly clearance but still stay long enough to provide decent support for the piston skirt at the bottom of the stroke. There was indeed a lot of work in the block, and notching at the bottom of the sleeves, to get everything to clear. However, I think it was worth it, and in fact with the availability of a 6.625" rod, I wish I had gone with the 4.75" stroke. I don't think it would have been too much extra work to make that one fit, over what I had to do already with the 4.6" arm. And I would have had a 600" FE, maybe a first...
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Thanks Jay, it does.
Drew, I don't know what is the limit for maximum cubic inch for an FE.
Here's the deal. I built my 427 Cobra back in 2000 with a 428FE that I bought from Carroll Shely's new shop in Vegas.
A few years later the rocker shaft at #1 cylindrer broke and pushrod bent 90°, so I rebuilt it and it had little over 400 rwhp.
Several people on another forum said going .030 over is risky
With high medical bills I had to sell the engine and tranny 8 years ago. Now that my health is better, I'm wanting to ger her driving again.
I've built several cars in my life, but the Cobra is amazing and a crap load of fun.
Now on a limited budget (still paying medical bills) the FE engine blocks and parts are crazy high in price. Because I want 600 + HP & TQ, I don't know with factory blocks if that's possible ? I really want a new side oiler, but $4,000 plus is just too much. The BBM block and heads are beautiful.
I like planning and researching everything,.... (it took me 2 weeks to buy a new microwave) and my wife says we can buy/build a engine next year, but hoping sooner. The budjet is apx $10,000, but I'm hoping $13,000. So to buy a 482FE with 600HP from $18,000 & up is out of the question. A friend and I can build a engine or I can buy a short block and asemble it myself.
I've always felt that no engine but a 427 side oiler or 428 will reside in my Cobra, but, because of cost I've thought of building a 385 series, 460.
I know I could include a 390/445, if need be, but a side oiler or 428 is what I want.
I found a original 427 side oiler for $6,000, but would kind of hate to molest it, by boring, stroking the block and bying a rotating assembly, etc....ending up being a 6k block. lol
Or side oiler here for sale- $8,500 or offer-
http://fepower.net/simplemachinesforum/index.php?topic=4677.0
This is where you guys come in. What and how can I build a 600 + HP/TQ FE with a tight budjet ?
Kevin
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Sorry, I got busy so it took me a lot of time to wright my last post.
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How about this plan.. find a good sound 428 block that will go 30 or 40 over... add a 4.25 stroke crank. This is probably a fairly common combo so someone should have a rod and piston combo worked out. For 600 horse you need around 300 cfm of air flow.. Order a set of heads from one of our builders that flow in that range. 10.5 compression, hydraulic roller cam (you could do it with a flat tappet solid too and save a few hundred), 2x4 intake, and you should be at 600 hp plus or minus.. This should be achievable for 10K
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Why chase max bore and stroke to attain 600hp?
!!!
The reason I ask that...... Hiss427 has posted here multiple times over the past year or two (385 forums too).
-He says he doesn't have much money (which is a common issue, I suffer from this as well)
-He needs 600hp for his kit car
-He is pretty much starting from scratch
Given this scenario where maxbore/stroke= more money, and 600hp isn't impossible to reach in a variety of ways, why worry about what max is?
Just build a 600hp engine. Royce provides a thrifty way to do so above.
The dyno and track subforums on this page provide a few 600hp engine recipes.
Hiss427 also does not seem to be opposed to a Windsor or a 460 based engine. 600hp is easier still with those platforms (tho I tend to think a 460 in a cobra would be a pain).
If money was no issue whatsoever, sure..... an under achieving oversized engine is always fun, but in this case it is overkill and wastes precious funding that would be better spent elsewhere.
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600 crank hp from a 482 stroker should be very doable with good heads, fat solid cam and some compression.
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The 4.75 was one of my builds.
It was a Pond block.
Crank is a Scat billet.
Rods were custom made steel from R&R in Illinois in an odd length..
It is a Cammer - so no cam clearance issues. But virtually every surface of the block interior needed "loving", and the counterweights of the crank ended up needing a severe amount of contouring to clear the piston pin bosses.
I don't think I would want to do it again....
What is the largest cubic inch FE you know of?
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Regular FE, not SOHC: 4.440 bore x 4.400 stroke = 545.004 cubic inches. Shelby big bore option, or BBM taken out to 4.440 will supposedly still have enough thrust wall to be safe. It has been done. Joe-JDC
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With budget in mind, a standard bore 352 stroked to 4.25 will make a "427" and a relatively easy 450 or more hp. While it's not the magic 600hp, it will still make a Cobra "clean the ditches" as they say... just something to think about.
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Maybe a better question is "how many cubes" can we adequately feed with current FE head capabilities? The best wedge heads I have seen are right around the 400cfm range, while the best SOHC heads are in the 450-460 ranges.
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Maybe a better question is "how many cubes" can we adequately feed with current FE head capabilities? The best wedge heads I have seen are right around the 400cfm range, while the best SOHC heads are in the 450-460 ranges.
Valve size is something to consider as well...
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Maybe a better question is "how many cubes" can we adequately feed with current FE head capabilities? The best wedge heads I have seen are right around the 400cfm range, while the best SOHC heads are in the 450-460 ranges.
So what displacements are those respective flow ranges adequate for?
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Regular FE, not SOHC: 4.440 bore x 4.400 stroke = 545.004 cubic inches. Shelby big bore option, or BBM taken out to 4.440 will supposedly still have enough thrust wall to be safe. It has been done. Joe-JDC
That's a big FE. Is it around here?
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"I know nuthin'". The billet Moldex 4.400" stroke was accepted as the longest stroke feasible, and Shelby offered special liners called the "Big bore" option for years. My personal BBM is 4.390" x 4.375" for 530 cubic inches. My Shelby is 4.250" x 4.125 all aluminum. Joe-JDC
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I like the point Barry brought up. If you could get to 600 plus cubic inches where/who is going to have a cylinder head/intake combination to feed it. Certainly nothing that isn't custom all the way.
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Considering all the aftermarket parts out there, the FE can be built well beyond its original design in terms of displacement and performance.
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"I know nuthin'". The billet Moldex 4.400" stroke was accepted as the longest stroke feasible, and Shelby offered special liners called the "Big bore" option for years. My personal BBM is 4.390" x 4.375" for 530 cubic inches. My Shelby is 4.250" x 4.125 all aluminum. Joe-JDC
Joe, the BBM's 4.390" x 4.375" for 530 cubic inches is great. Just wish I could afford one. ;)