DIY Naturally Aspirated 6.2L Build

[bubblehead93]

As has been stated many times, not many options for these motors from a performance perspective.

I have a 2011 Raptor Supercrew that I have owned since new... CAI, LT headers, and tune plus a number of suspension mods...

While the motor has only 85,000 miles on it I've been hungry for a long time to start building a motor before what limited aftermarket that does exist dries up...

There is practically only one source for performance parts on these motors and while I started looking to build a stroker motor I realized that the 400 cui offering out there was an expensive ~0.065" (4.015" to 4.080") overbore and a 0.080" (3.74" to 3.82") increase in stroke.

So while 400 cui is a cool number, I decided against pursuing a stroker and instead pursuing an overbore option which will yield a ~392 cui motor.

I'm staying n/a so higher compression is in order, just shy of 11:1 through some custom pistons (Diamond) on Manley rods.

The cams will be a Dan Crower (DCR) regrind and Cody Dawson (Perfect Circle Engines) will be prepping a set of heads for me.

The truck is a daily driver, so the cost will be a bit higher as I'm going to build a separate motor by sourcing good cores (block, crank, and heads) and assemble the long block so that I just need to swap over the accessories and intake once it is time for the motor swap.

Timeline for the build will be mostly driven by discretionary time on my part so please be patient.

Intend to post pictures along the way... so I hope this will be helpful for some to outline a build they could do...

In any event, welcome to my journey if you care to come along...

 

[B E N]

If you can find a block that is in good shape I would be really inclined to keep the bore to a minimum. Thin cylinder walls are no ones friend and these blocks aren't real meaty to begin with, it also gives you a chance to bore it again in the future if required.

Rather than trying to up the displacement (6.2l-6.6l is 6%) increase the rev range like you are talking using quality bottom end parts and good cylinder head components. A peak power rpm increase from 5500 rpm to 6000 rpm is 9%, so you are already exceeding the strokers airflow ability. If you can push to 6500 you will be even better off. When you start adding head flow and cam lift to the equation you can get where you need to be. Yes the extra 6% displacement will net 6% flow across the board but for a driver, and the cost of all the parts involved it just doesn't make sense. Just different ways of achieving the same thing, max effort would be a stroker that revs.

Boost will net you far more power, for less cost, 7.3 psi = 50% flow increase. It will also drive around better and it is very likely your fuel economy will be better with a supercharger than it will be with a stroker (at least when cruising).

 

[bubblehead93]

First discussion...

Cam re-grind...

So along the lines I discussed in my first post, daily driver, so I needed to source another set of Raptor cams to send off...

If you search eBay and other sites, everyone prices Raptor parts as if they are made of unobtanium...

good news, you can still order a brand new set of oem cams from Ford... AL3Z6250F and AL3Z6250E for about the same or less than as I see them priced used online (~$250.00 to my door)...

Once these come in I'll get them sent on to Daniel Crower Racing for a re-grind for a but more lift and duration than stock which should pair nicely with the higher CR. I'll share the spec card once I have it in hand. Quoted a 3 week turnaround.

Rods (Manley 14322-8) are on their way from Summit (actually drop shipped from Manley) and Diamond is working on the custom piston order. Since they already have a 11.0:1 CR piston in their lineup, the custom piston is really just a bigger diameter of their off-the-shelf 6.2 piston with a slighter smaller dome (+4 cc versus +6 cc for p/n 30602-8 and 30603-8 which are 4.020" and 4.030" bore pistons). Calculated compression ratio is 10.9:1.

Have a great Raptor day!

 

[bubblehead93]

If you can find a block that is in good shape I would be really inclined to keep the bore to a minimum. Thin cylinder walls are no ones friend and these blocks aren't real meaty to begin with, it also gives you a chance to bore it again in the future if required.

Rather than trying to up the displacement (6.2l-6.6l is 6%) increase the rev range like you are talking using quality bottom end parts and good cylinder head components. A peak power rpm increase from 5500 rpm to 6000 rpm is 9%, so you are already exceeding the strokers airflow ability. If you can push to 6500 you will be even better off. When you start adding head flow and cam lift to the equation you can get where you need to be. Yes the extra 6% displacement will net 6% flow across the board but for a driver, and the cost of all the parts involved it just doesn't make sense. Just different ways of achieving the same thing, max effort would be a stroker that revs.

Boost will net you far more power, for less cost, 7.3 psi = 50% flow increase. It will also drive around better and it is very likely your fuel economy will be better with a supercharger than it will be with a stroker (at least when cruising).

Thanks for sharing your thoughts, ship has sailed though... pistons are ordered... block will take a 2 mm overbore... stock is a 102 mm piston, so 104 mm is the limit, the 4.080" piston is 103.6 mm piston. So I'm essentially taking all of the life out of the block. New blocks don't have issues with core shifts and such like old SBF and FE motors I grew up with... I've get the s/c thing, I have a modded 03 Cobra since it was new... blower whine is cool... but I am pursuing a n/a 6.2L which I concede will make less power than if I had spent that same money on a Roush or Whipple S/C setup... but it will be cool... and I doubt I'll run into anyone with one quite like it...

 

[CoronaRaptor]

Make sure you post lots of pictures. There is another member that is rebuilding a spare engine as well on here, his is more on a budget, but it is a great build as well. Are you planning any bling? Like powder coated valve covers, that sort of thing?

 

[bubblehead93]

Make sure you post lots of pictures. There is another member that is rebuilding a spare engine as well on here, his is more on a budget, but it is a great build as well. Are you planning any bling? Like powder coated valve covers, that sort of thing?

yeah, I've been following his build and empathized when he had to make some hard rod and then piston choices. I'll definitely provide lots of pictures as well as some how to stuff, like degreeing the cams... never fun, BUT easier I hope than my 03 Cobra 4V... oh, and no bling... I'll paint the block black and likely black wrinkle coat the valve covers... leave the front timing cover and heads bare aluminum...

 

[bubblehead93]

While I'll still need to check piston-to-valve clearance, based on discussions with Diamond and folks who have built motors with Diamond's on-the-shelf 11:0 CR pistons and using DCR's re-grind cams I should not have any piston-to-valve clearance issues running the cams without phaser limiters or lockouts (i.e. same valve clearance as stock pistons). I suspect tuners would prefer the lockouts, so starting the conversation with my tuner now. You give up some power with the lockouts which is fine in a blown application but would be nuts for a n/a application.

 

[CoronaRaptor]

What do lock outs do?

 

[bubblehead93]

What do lock outs do?

essential renders the cam phasers inoperable, so they work like the cams in a 2V motor (or 4V for that matter), no variable cam timing...

 

[Raptor 2014]

I woud strongly suggest to t-gauge the bores of your block. I decent t-gauge can be purchased with a convexed head for around $300.00. Not all block castings are the same. Most decent machine shops have a least 1 so ask. It will only take about 5 minutes to check all the bores.

Adder T-gauge = electronic thickness tester