DIY Naturally Aspirated 6.2L Build

[bubblehead93]

sounds like your trying to get me to spend some money on new rods.

lol... not sure if I should not buy a set to have on the shelf...

 

[Canuck714]

Unfortunately I think you are stuck waiting.. Unless you commission someone to make you a set of rods custom, Manley is the only one I have seen that makes any 6.2 replacement rods.

Did you ever look into offset grinding the crank to hang chevy rods on it? I remember someone was doing that to make 6.2 ford stroker with off the shelf GM performance rods and JE piston set up.

 

[bubblehead93]

I looked into it, also spoke with darton and a couple of their tier one shops about feasibility of a darton MID type sleeve in a 6.2 block (this would be magic when you look at the bore spacing on the 6.2, the damn water jacket around each cylinder ruins it). When you look at the livernois kit, they went through a lot of work to gain 8 cui's (after overboring to a 4.080" bore they work the crank for a 3.82" stroke versus the stock 3.74", all to chase the magic 400 cui number). The 6.2 rods are very wide at the big end, 0.978". A big block chevy rod is wide enough (0.990" so you could narrow the rods) but the big end diameter is quite a bit bigger than the ford 6.2 (2.325" versus 2.239"). Also the only big block chevy rod you could use that is shorter than the ford 6.2 rod is the stock length rod at 6.135". So the whole thing is problematic... I don't think anyone is using a chevy rod to stroke a ford 6.2... again my experience is mostly with SBF and FE motors, so there may be cool techniques out there that I'm not familiar with.... I suspect livernois does a weld and ever so slightly offset grind job on the stock 6.2 crank to gain 0.04" of stroke and retains the stock 6.2 rod with custom pistons that change the pin height by the same amount to keep the deck height (and therefore piston-to-valve clearances) about the same...

sorry long post, when playing with these motors you are on a bit of a windy corner since not many others are doing anything with them and some of the folks that are messing with them are secretive about their product...

If I was going to spend big money I would fully explore the darton MID sleeve path... oh wait, I am spending big money, even bigger money with no guarantee it would work... lol

 

[bubblehead93]

so I've been talking with Geddes Racing Engines in Colorado Springs, CO... darton steered me that way... custom sleeves would require a sacrificial block just to explore the feasibility and possible design for a set of sleeves... then even more cost on top of that assuming if its even possible... more conversation to be had, but we started to talk custom rods (width being the critical dimension, in my mind, for offset grinding the crank) because of the 6.2 rod's small big end bore but large width... i kind of picture a SBC big end with both ends having the 6.2's width (0.978" vice SBC 0.940" or so)... all theoretical right now... still pressing with the current build, other than still waiting on parts... sigh... too much time to think...

 

[bubblehead93]

so good conversation with Geddes Racing Engines... so the plan... finish building the new motor (assuming hell freezes over such that all the parts I'm waiting on actually get delivered) and then take the old motor and build a custom stroker, a real stroker vice a big bore pseudo stroker, and try and make it what we used to call a square motor, bore = stroke, or at least as close as we can get it... so I've sidetracked my own thread for long enough... here on out the focus of this thread will be on the current build... if i had parts, trust me I would be talking about them... sigh...

 

[bubblehead93]

spoke to ARP direct, another 3 weeks for main studs... asked them how big is a batch when it works through their production que... she said thousands... probably an exaggeration, but if you want ARP main studs for a 6.2... order soon... lol

 

[bubblehead93]

Both ARP and Manley report no joy until after Xmas... this pandemic engine building thing is depressing...

 

[Pawl8901]

Keep it up & thank you. Had absolutely no idea about the rods or Pistons until you posted all this stuff. Am looking to do the same thing for my 6.2 because of this thread, praying in the next year. Power to you on the cam regrind though - the only other option is expensive like you said unless you get everything from them. Factory heads flow great and can be made better without going aftermarket too. I'll probably end up going the more expensive route if I can't make something work like it seems you are. Good luck!

**Edit: just read one of your brewer posts on the stroker part. You are not doing a stroker but wanted to share what I found. Much of it is speculation. Newer gas 7.3 and 6.2L engines appear similar in some ways. Looked around at a few places. Cannot 110% confirm but the 7.3 Godzilla crankshaft appears to be a fit in the 6.2. "factory-ish stroker" with modification to fit with the 6.2, but not sure yet. There's a YouTube video I can't find where they side they fitted one in there out of curiosity and it fit. From a few forum threads I also cannot find from outside this forum - It seems the 7.3 and 6.2 engines come from a similar cast because it appears the intake manifold runner locations are similar or exactly the same. Still need to confirm/not sure if you or anyone watching has heard about this. Would be incredible because they are doing aftermarket stuff for the 7.3 this time around. Would be nice to get the oem off with something different without making a custom adapter plate or going the route of sheet metal.

 

[bubblehead93]

Keep it up & thank you. Had absolutely no idea about the rods or Pistons until you posted all this stuff. Am looking to do the same thing for my 6.2 because of this thread, praying in the next year. Power to you on the cam regrind though - the only other option is expensive like you said unless you get everything from them. Factory heads flow great and can be made better without going aftermarket too. I'll probably end up going the more expensive route if I can't make something work like it seems you are. Good luck!

**Edit: just read one of your brewer posts on the stroker part. You are not doing a stroker but wanted to share what I found. Much of it is speculation. Newer gas 7.3 and 6.2L engines appear similar in some ways. Looked around at a few places. Cannot 110% confirm but the 7.3 Godzilla crankshaft appears to be a fit in the 6.2. "factory-ish stroker" with modification to fit with the 6.2, but not sure yet. There's a YouTube video I can't find where they side they fitted one in there out of curiosity and it fit. From a few forum threads I also cannot find from outside this forum - It seems the 7.3 and 6.2 engines come from a similar cast because it appears the intake manifold runner locations are similar or exactly the same. Still need to confirm/not sure if you or anyone watching has heard about this. Would be incredible because they are doing aftermarket stuff for the 7.3 this time around. Would be nice to get the oem off with something different without making a custom adapter plate or going the route of sheet metal.

thanks for pushing the 7.3 crank insight... same bore spacing... same main journal bore... coyote rod journals... a stock length coyote rod might work with custom pistons... with a 4.080" custom piston you would see about 415 CUI... might work, the snout of the crank would be the critical part since the 7.3 uses a chain driven oil pump I believe... so the snout of the crank would need to be machined (perhaps welded) for the 6.2 oil pump drive... a 7.3 crank forged steel crank can be had for about $440 based on a quick google search, I might pick one up and take some measurements...

 

[bubblehead93]

My thinking right now is a keyed, pressed on sleeve (perhaps with a little crank machining) that would "convert" the 7.3 crank snout to mimic a 6.2 crank snout... one project at a time... I would have less time to think about future projects if all my current projects were not stalled... motor for the Raptor, nitrous and a J2 Fabrication A2W setup for my Cobra... back order, back order, back order...