Learn me: LSx Heads, and which to modify

When you measure the center to center bolt spacing of the head bolts between the Ford 300 I6 and the LSx engines you get a mismatch of maybe 0.05" or something similar.  So then we've got this for inspiration https://bangshift.com/bangshift1320/mad-science-a-drag-racer-sliced-and-diced-a-pair-of-ls-heads-stuck-them-together-and-mounted-them-on-a-ford-inline-six /

Engine will be a Ford 300 in a '93 F150.  Current daily driver and would like to keep that ability, so drivability will need to be a a factor for the cam, idle, and other components.  One day a turbo may enter the mix.  Which head should I look for in a yard?  Fot that matter, what is going to be the best way to weld it together?  From what I remember of research on FordSix its better to cut the heads like: 00|00 and 0|00|0 and weld them together as 00|00|00 to eliminate the buildup of tolerance issues.

Thoughts?

All I've got is avoid 806s with the perimeter bolt valve covers.

Depending on what part of the country your in I have a ruined 862 I could donate to this cause. I think you could cut off the end of that I ruined trying to drill out an exhaust bolt and make it work for this program. It's partner is still here too if you're interested. 

This might be relevant to your interest. 

In reply to Daylan C :

I'll look into the 862s and see if they would work.  If you're coming down to the Challenge I'm just in Tampa so I could meet up.  I'm in no hurry

In reply to Mr_Asa :

I had planned on attending the challenge as a spectator this year so I could definitely bring them then. 

According to that website, looks like the 862s have the smaller intake and exhaust valves, which makes sense for the 4.8-5.3L engines Vs the larger.  Not a deal breaker as I'm still not sure how that would play into my goals and virtually anything is going to flow better than the Ford head.

In reply to Daylan C :

Awesome, now we just need this dadgum virus to go away before then

A lot of turbo guys have made good power with 862s. I'm only swapping to 806s on my 5.3 because I ended up with 2 good pairs of 806s cheap (and 1 good pair of annoying to find valve covers) 

Actually, thinking of it, it might make a lot of sense to get a head from an engine in the 4.8-5.3L range for an engine in the 4.9L range.

Why not just drop a V8 in if you are gonna bother making a bespoke head

In reply to ChrisLS8 :

For pretty much the same reasons I didn't do the same thing with my Mustang, despite swapping the entire suspension and drivetrain to support it.

In the end, its just kinda boring to have the same vehicle as everyone else, even if it takes me 10x longer to do everything. 

Mr_Asa said:

Actually, thinking of it, it might make a lot of sense to get a head from an engine in the 4.8-5.3L range for an engine in the 4.9L range.

4.8 to 5.3 V8 (0.6 to 0.7 per cylinder)

4.9 I6 (0.8 per cylinder)

If you want to come close to matching cylinder size (may not want/need to), you would need heads from a 6.0 or bigger.

The Ford 300 and the 6.0 LS both have a bore of 4.000, yes?

Matthew

In reply to matthewmcl :

My thinking too.... a 300 six would have per-cylinder displacement like a 400ci V8.

On the other hand a 300 is not exactly a rev to the moon type of engine, so going with square port 6.2 heads is probably overkill.

4" bore on the 300, so if your bores are centered on the head chamber as they would be on the v8, i would go L92/ls3 rectangle port heads.  

Thanks guys, I shouldn't think when I'm up past my bed time.

Knurled, I do know one guy that drag races them, he shifts north of 6k from what I remember; most of the limitation with the rev-ability is back to the head being so asthmatic but he has modified the block and rotating assembly.  I wouldn't be surprised if a good flowing head and matching cam added around 1000-1500 RPMs to the engine, its not hard when a mostly stock engine shifts around 3K

How do you actually weld two heads together.  I mean I understand the concept.  Cut the back cylinder off one and the front off the other and glue them together.  BUT what is teh actual process for welding them together.  I assume set up a jig (maybe the actual motor) and then get to welding and then machine as needed?  Is it really that simple? I guess I am wondering about internal passages.  Do you then just cut it open to get at those and then weld the outer piece back on?

I have never seen it done or actually detailed on how to do this.

In reply to dean1484 :

OHV cylinder heads are surprisingly simple.  There are no oil passages to worry about, no cam bores, nothing like that, it's a shell around a water jacket.  Slice 'em open, get a hefty V notch, weld 'em  all around, make the flat surfaces flat again, and away we go.

Much less ambitious than, say, the guys who used to take Nissan KA24 heads and play hack-and-slice to make 24v heads for Nissan L24/26/28 sixes.  (This was before it was cheaper to just buy an RB20/25 engine, which is... a DOHC 24v L-series six)

This is amazing, please document it here! 

I think step one is identifying the pistons in the 300.  LS heads have a few different chamber sizes to cover the wide range of compressions and displacements across the line of offerings.

The 035 and 317 heads for instance had the same ports as the LS6, but with a larger chamber for the 6.0L truck application.  The 243/799 castings on the LS6 just had smaller chambers.

I would disagree about the rectangle port castings from an LS3 or a truck/van.  They give up low-rpm velocity big time, and a Ford 300 has long strokes and big heavy components.  It was designed for 4000 rpm redlines.  Stick with cathedral ports.  More common (cheaper), makes more velocity (which means torque) and let all the "big boys" spend money on the rectangles.

LS heads are also nearly a bolt-on for a Windsor.  You have to hog out a couple head bolt holes, but it has been done.

In reply to Curtis73 :

The biggest issue with the Ford V8s besides the camshaft order problem (LS valve order is reversed) is the Chevy engines' leading bank is on the other side, so you can't easily use a Chevy intake manifold.

I've seen attempts to hack and section a carb manifold for an LS headed Windsor and it looked like a good way to spend 40 hours with a TIG and a milling machine.  Seems to me that it'd be the perfect opportunity for 3D printed manifolds, as I doubt the swap would ever catch on beyond one-offs.  (Or run an independent runner setup for the real old school Ford vibe)

I DO wonder some times if the Chevy water return passages in the deck would line up with the ones on a 351C, since they both have dry intake manifolds and run the thermostat through the block instead of the intake.  Then I remember that the worst part of the Cleveland (in North America) was the weak-o block, so it probably makes more sense to put 351C heads on a Chevy engine. 

I didn't say it make a lot of sense, just more sense.

I think the only reason to do it is for the "art" of it.  More of a just-because-you-can scenario.  Congrats; you just put LS heads on a 302.  You now have the same performance potential as if you had bolted LS heads onto an LS.

I always laugh at the folks who weld and drill LT1 heads for SBCs.  If they use the aluminum heads, they get a few more cfm more than a smog head, and if they use the iron LT1 heads, they just went through all that work to get Vortec heads.  The Iron LT1 heads flowed a bit better than GM expected, so they directly copied those ports for the 062/906 Vortec heads in 96.

In reply to Curtis73 :

"Because it's there"

See also:  Hacking and splicing KA24DE heads to make a 24v head for an L28 engine