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Discussion Starter · #1 ·
Crossposting this from Ranger Power Station, it's no real big secret that Tom Morana and Super Six Motorsports use a factory Ford crankshaft to make their stroker kits for the 3.8L Essex V6 (They use a 4.2L crank). So I started digging to find out where Morana was getting his cast "stroker" crank for the 3.0L Vulcan and I believe he is using a machined 3.8L Essex V6 crankshaft.

- The main bearing journal diameter of the Vulcan and Essex cranks are identical.
- The piston pin bore on the connecting rods are identical between the two engines.
- The Essex's connecting rods are .382" longer than the Vulcan's, which may be able to be used to improved the geometry of the rotating assembly (Less side-to-side loading, more vertical movements, which means more stability and less wear) and increase rod ratio.
- The crank pin bore of the connecting rods are .1766" larger on the Essex.
- Due to the above, the connecting rod journal bearings on the Essex are .185" larger than the Vulcan.
- The crank snout is also a tiny bit larger (Still within the .150" range).
- Rear main seals are near identical in diameters between the two engines.

Do the math, the Vulcan's bore and the Essex's stroke, then paired with .060" over pistons and you get 3.3L, which is what Morana is advertising.

Due to the slight variances in cranks, it should be possible to have the Essex crank machined to fit the Vulcan's timing crank gear and harmonic balancer and perhaps the Vulcan rods and rod bearings. All in all there is a possibility for getting a "stroker kit" for less than $300.

Any takers, guinea pigs? Brad (loudsho92) I'm looking at you :D.
 

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Your logic sounds pretty solid to me - the only issue I would bring up is piston height. What are the deck heights of the Essex and the Vulcan? The longer Essex rods may bring the pistons up too high and thus create a piston-to-head clearance issue.

I just looked at the site and the Morana stroker kit comes with Diamond forged pistons (presumably custom ordered.) It doesn't give much mention to dimensions, nor its oversize. Unfortunately, if new pistons need to be machined, it would send the price of the build through the roof... :(

Just my $0.02
Ian
 

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Your logic sounds pretty solid to me - the only issue I would bring up is piston height. What are the deck heights of the Essex and the Vulcan? The longer Essex rods may bring the pistons up too high and thus create a piston-to-head clearance issue.

I just looked at the site and the Morana stroker kit comes with Diamond forged pistons (presumably custom ordered.) It doesn't give much mention to dimensions, nor its oversize. Unfortunately, if new pistons need to be machined, it would send the price of the build through the roof... :(

Just my $0.02
Ian
+1

Tom's kit would be a direct bolt-on, and wouldn't require boring of the block for .060-over pistons. Also, I've read somewhere that .040-over for pistons is around the safe limit (I think rogueperformance.com)
 

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Discussion Starter · #4 ·
Alright, the 3.9L that appeared for only three years starting in 2004, was the Essex 3.8L with a slightly larger stroke (3.464"). Stock Vulcan bore, 3.500", and Essex's 3.9L stroke, brings the displacement to 3.275 liters and round up to 3.3L (Like Ford did with the 302, it's really 4.9L). All Essex cranks (3.8, 3.9 and 4.2) have the same bearing diameters, the only difference is in the stroke of the crank.

The only problem with stroker cranks, in any engine, is when kept with stock length connecting rods, the rod ratio drops. Endurance and racing engines are built with high rod ratios, usually in the 1.90 to 2.1 range, as already mentioned, the higher the rod ratio, the better the geometry of the rotating assembly, less side-to-side loading of the piston and more vertical movements, less friction, less wear. Stock the Vulcan has a decent rod ratio for a factory engine, 1.76. With the 3.9L's crank it drops to 1.6 (Which is still alright, 1.6 is actually stock small block Chevy range). If someone were to try the 4.2's crank (3.74" stroke) and managed to get it clearanced, the rod ratio would plummet to 1.48, but you would have a 3.5L engine..

Deck heights I am having trouble finding.
 

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I like where this is going. Keep up the good work. You got a watcher out of me.
 

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Also, I've read somewhere that .040-over for pistons is around the safe limit (I think rogueperformance.com)
Ideally you would want to keep the overbore to as little as possible. Even though .060" over would add 7ci to the total, it would run into issues of detonation and poor cooling (the thinner cylinder walls would absorb less thermal energy and thus result in higher cylinder temps.)

It's been argued that when overboring a Vulcan, machining from 3.504" to 3.552" (89.1mm) would be a valuable asset as modular Mustang pistons are this size and are thus a dime a dozen... but again the 0.048" overbore is pretty iffy.

Run the numbers by me... What are the actual sizes of the rod journals, the connecting rod sizes, etc? Lets compile all the data and see what would be the best match.

I'm still thinking custom pistons are in order.... I think the deck height will require a shorter piston.

By the way, Ford didn't round up on the 302... They cheated! It's actually 4942cc and shouldn't round up ;) But since the 5.0L stopped being marketed in the Mustangs in 1993 and we still remember the moniker, obviously they did something right!

EDIT: By the way, since we're talking long-rod setups, what are the length of the Essex rods? Since our connecting rod journals are 2.310" from the factory, an offset grind, 0.010" under for 6" BBC (2.200") rods could net us a stroke of 3.564", in a 30-over Vulcan netting 209.8ci (3437cc)...
 

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Discussion Starter · #7 ·
Run the numbers by me... What are the actual sizes of the rod journals, the connecting rod sizes, etc? Lets compile all the data and see what would be the best match.

EDIT: By the way, since we're talking long-rod setups, what are the length of the Essex rods? Since our connecting rod journals are 2.310" from the factory, an offset grind, 0.010" under for 6" BBC (2.200") rods could net us a stroke of 3.564", in a 30-over Vulcan netting 209.8ci (3437cc)...
Vulcan
Con rod journal - 2.310"
Con rod length - 5.53"

3.8L
Con rod journal - 2.426"
Con rod length - 5.912"

3.9L
Con rod journal - 2.426"
Con rod length - 6.089"

4.2L
Con rod journal - 2.426"
Con rod length - N/A
 

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So you can offset-grind the 3.9 crank 0.116" to fit vulcan con rods, provided they won't hit the cylinder heads, and push a 3.522" stroke. With the vulcan's 3.5" bore; 3.332L (3.3). If you overbore .020 to get a nice square bore & stroke, 3.37L, or round up to 3.4.
 

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Vulcan
Con rod journal - 2.310"
Con rod length - 5.53"

3.8L
Con rod journal - 2.426"
Con rod length - 5.912"
84FordMan, I believe your specs for the journals are actually the bores of the connecting rods, not the journals.

The Haynes manual in my lap for 86-95 Tauruses tells me that the con-rod journals for the Vulcan and the 3.8 Essex are 2.125" and 2.310", respectively.

Consider this link, for a set of replacement Eagle rods for the Essex:
Racingworks.com - Eagle Connecting Rods, H-Beam, 6.090", Ford Essex V6, 3.8L 1982-1997 Mercury Universal Essex V6 3.8L

I believe good old SBC rods would be the best bet - they are machined for 2.1" journals, are 5.7" long and are a dime a dozen. That way the Essex crank could be offset-ground, to produce a 3.534x3.664" motor. The motor would total 215.6ci, (3533cc) and have a rod ratio of 1.556:1. Not the best, but still acceptable for a street motor.

With the right cam and a set of hogged out heads, we could be looking at a 250-300hp Vulcan B)
 

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Gravedig.

My neighbor keeps telling me how in the old days, they'd swap parts out of motors from different manufacturers to get the biggest/best of everything. Tom's a little old-school, so let's see where else we can look.

GM's 3100 has a 3.5" bore, so its crank will take us to 3.1, which you can accomplish with an off-set grind. Their 3400 is just a bored-out 3100, so no luck there. Their 3800 is the 3.8 Ford's Essex was based on (shh) and we'll run into the 90-60 degree problems. It's entirely possible to off-set grind the rod journals at some mathematically determined opposing angles to bring the 90 degree crank to 60 degree pattern, but let's call that plan B.

Looking at Chrysler, the Dodge Caravan's 3.8 is a 60 degree pushrod with a 3.43" stroke, which would put us at 3.2514, which can JUST be acceptably rounded to 3.3L. It's been around since '91, so they're available. Can we find specs on that crank?

The only other major company I can think of brings us back to Ford, with the 4.0 Cologne. It's a 60 degree, and although its stroke is 3.32, pending crank specs it might require an off-set grind of ~0.1" or so to throw us around 3.25L.

Does anyone know where I can drag up these specs? Google is only my friend for so long...
 

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+1

Tom's kit would be a direct bolt-on, and wouldn't require boring of the block for .060-over pistons. Also, I've read somewhere that .040-over for pistons is around the safe limit (I think rogueperformance.com)
I went .060 over (Ross pistons) on my build - Ford says 5.0 pistons (.049 over) are ok - I started with three 3.0 vulcan blocks to magnaflux and verify no microscopic cracks and chose the best one with the thickest cylin wall thickness. - .060 is doable.
 

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Ok, so I did some math. It's late so please correct anything if I've gone all wrong.

WARNING: MATH

V6 engines fire every 120 degrees. With our firing order (3.0 and 3.8) being 1-4-2-5-3-6, 1 and 4 fire 120 degrees apart. On the 3.8's 90 degree setup, #4 piston is already 90 degrees apart, so it's rod journals are 30 degrees apart per opposing pair. On a 60 degree, they're 60 degrees apart.

So, on the 3.8's 3.390" stroke, main center-line to rod center-line is half, at 1.695"

To find rod center-line: 2[(1.695"Cos15)Tan15] = 0.877"

The vulcan's 60 degree setup will need twice that distance, at 1.755" rod center-line at 3.390" stroke, so they need to be separated by 0.877", or 0.4387" each journal. This will leave us with a rod journal of just 1.871". I honestly don't have enough experience to know if that's too small, but if a Chevy V8 can manage 2.1", then I think 0.2" can't be TOO bad. It's just a matter of finding the right rods and bearings.

The 3.9 and 4.2 are immediately ruled out, because as the stroke gets longer, the rod journal center-lines move further away (to keep the same angle). This would lead to smaller journals, and a compromised crank.

The stroke will only get us up around 3.2, but it's better than 3.0, and somehow my lecture about torque multiplication comes into mind. Displacement aside, won't our engines produce more power simply because the torque is applied further away from the fulcrum?

I'll take it.

And I'm still looking for specs on the dodge crank. Can anyone let me in on where you're getting these figures?
 

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Stroker crankshafts were available for the SHO V6 which has many dimensions in common with the vulcan since the original concept for the SHO was for Yamaha to design and make DOHC heads for the vulcan 3.0. Yamaha ended up making the entire engine for the SHO, because the vulcan was not strong enough where the crankshaft was supported to withstand 7000-9000rpm operation for long periods of time. Two stroker crankshafts were available. One was a rewelded crankshaft. Material was added to the rod journals then offset ground to increase the stroke .25". Second was a custom made forged steel stroker crankshaft which costs about $3000. The high cost was because the demand, hence the volume, was very low compared to stroker crankshafts for the windsor V8 or small block chevy. These stroker crankshafts with the .120" over bore on the 3.0 SHO gave you a 3.6L. The engines also required custom made pistons to relocate the pins higher in the pistons. You can still go this way with a stroker, but it will cost some serious $$$$. The welded crankshafts did not last with a Supercharger, but the forged ones did.

Bob
 

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I appreciate your post. I remember reading that a Yamaha crank will fit in the vulcan with some machining, but I ruled that out because it has the same stroke. The $3000 crank defeats the purpose, because we're trying to save off Morana's ~$2000. How much did the 3.4" stroke cranks go for? Weren't Yamaha internals forged from the factory?
 

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This is all very interesting, but I have to admit, I would rather just buy the bolt in Morena stroker kit. By the time you are done getting parts machined and get the trial and error out of the way, you will have as much invested into it as the stroker kit costs. The exception would be if you have your own machine shop and your time isn't that valuable.
 

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The 3.4L SHO motor developed by the SHO Shop was sleeved and rebored engine. One of the guys on the SHO forum made a 3.4L stroker by offset grinding a SHO crank and used custom made rods with 3.2L pistons.
SHO crankshaft and rods are forged. The SHO crankshaft is also supported by a steel girdle that bolts to the main bearing caps.

Bob
 

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Sorry, I meant 3.4" stroke, not 3.4L engine. A 3.4" stroke would net us around 3.2L. And I think loudsho92 strikes home about supporting the small aftermarket we have. Tom researches these things on his own dime, and the vulcan crowd would be sunk without him. My quest just stems from my plans to bore out a vulcan block as well, which wouldn't be fun to buy new pistons in addition to the $2500 he now charges.
 

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ok guys, im new here but im a dodge fanatic. ive got a particular taste for the 93/97 LH platform (dodge intrepid, eagle vision, plymouth lhs plymouth new yorker)weve taken ignorance to a new level on those cars with some of the strangest combos youve seen, for theres a specs thread that has all the engine specs between the 3.3 and 3.5 (only eninges for the lh family till 98) chrysler does have a 60 degree 3.8 that crank info wasnt posted but a guy there username chewievette put the 3.8 crank in a 3.3 to build the ONLY chrysler 3.5 OHV motor around. the factory 3.5 is OHC. go to www.allpar.com any information you can concievably ever need for the chrysler motors. as far the gm engines hang that bs up, ive been neck deep in gm 6s for 12 years the only 60 degree parts we should even think about for a ford motor is rods and possibly pistons, for the crank chrysler will be the best bet. the 60 cranks have a rep for being weak..... they are not unless they are starved for oil... then what crank isnt right? im off to all par to hunt up some specs.
 

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chrysler stuff
3.8L (96.0 mm x 87.0 mm =) 43.5 mm StrokeHt + (1.377*25.4 =) 34.98 mm CompDist = 78.48 mm
3.3L (93.0 mm x 81.0 mm =) 40.5 mm StrokeHt + (1.241*25.4 =) 31.52 mm CompDist = 72.02
mmMain Bearings
Journal Diameter ......................... 2.519 (64.00)
Connecting Rod Bearings
Journal Diameter ......................... 2.283 (58.00)
piston Pins
Diameter .................................. .901 (22.88)

i would post a link to the full info but you gotta be a member to view it. but the site is www.dodgeintrepid.net search the first generation forums namely performance mods FAQs
 
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