LS Headed 300: Brainstorming problems

Hello all

If you remember from this thread, I'm planning on doing some dumb E36 M3 that should be fairly awesome when its done.

I finally got the heads Daylan donated to the cause (thanks man!) and had a chance to look at some stuff.

First off, head mismatch.  It isn't .05" like I thought, but closer to . 08", there is also a small side-side difference, but a slightly bigger drill bit than the hole will solve that if I don't want to mill it.  Due to this, I'm no longer thinking of cutting the heads as I specified in the previous thread:

Mr_Asa said:

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?

But more like O|O|O|O O|O|O|O and welding them like O|O|O|O|O|O to eliminate the tolerance.  Anyone think this might be overkill?  My idea is that the original will have the center of the cylinders slightly offset from the center of the heads.  Am I overthinking this? I have a tendency to do so.  One benefit of the new way is that I could 3d print some jigs and with the head bolts it'll be even throughout to help fabrication later

Next brainstorm, valvetrain sealing.  I have no real ideas for this. 

It will also be something of a monstrous angle on the pushrods, and I'd like to lessen that as well for reliability.  Anyone have any thoughts?  I'm thinking I'll need to get a set of rocker arms from a yard, put them on one of the heads and then use one of those adjustable test pushrods to see how bad it actually is.

Edit: 
Related threads I've started

https://grassrootsmotorsports.com/forum/grm/intake-design-and-building-how-to/186000/page1/

https://grassrootsmotorsports.com/forum/grm/ignition-signal-from-tonewheel-on-crank-vs-camshaft-driven-electronic-distributor/182213/page1/

https://grassrootsmotorsports.com/forum/grm/what-non-ford-transmissions-can-mount-up-to-a-sbf-bolt-pattern/192035/page1/

https://grassrootsmotorsports.com/forum/grm/learn-me-lsx-heads-and-which-to-modify/170258/page1/

This is significantly more ambitious than the crossflow on a US200 block that I haven't finished. Rock on!

Yikes! Does that mean you would have a weld right through every head bolt hole in the head?

Edit: I assume the bolts in the heads look like this :O:O:O:O: - so basically other than the outside 4 I dunno how you'd cut to avoid cutting right through where the bolts go. 

Audi 4.2 V8s had 88mm bore center heads (like the 3.6, and the four cylinders) but the blocks were stretched to a longer bore center (90? 92? i forgot) so they could get over 500cc/cylinder.  The end cylinders were significantly off center, way beyond .08".  They made many thousands, if not millions, of them.

Robbie (Forum Supporter) said:

Yikes! Does that mean you would have a weld right through every head bolt hole in the head?

Edit: I assume the bolts in the heads look like this :O:O:O:O: - so basically other than the outside 4 I dunno how you'd cut to avoid cutting right through where the bolts go. 

Pretty much, yeah.

Others have done it the way I originally laid out, such as this guy (who wants $2500 for it, if I remember his email)

https://engineswapdepot.com/?p=35769

In reply to Pete. (l33t FS) :

Interesting.  So maybe go with my initial plan for chopping and welding?

In reply to Mr_Asa :

I'd do the minimum number of welds because you ARE going to warp the snot out of everything.  The two/two/two seems like the best compromise.

In reply to wheels777 :

That's be a great high RPM screamer.  Have you guys gotten any where with any of the issues with it, or still planning?

In reply to wheels777 :

I hope this comes to fruition because I think that'd be rad as all hell.

I wouldn't worry about the bore spacing difference...its not enough to cause any problems. Especially in the 2+2+2 configureation. If you're going to port the chambers to match the 300 bore you'll need to grind them out to match anyway.

The pushrod angle is a non issue. Ever seen the crazy angle of a Small Block Mopar??? big angle on those pushrods and they work just fine.

In reply to asphalt_gundam :

I hadn't seen those, no.  Good to know, I wonder if Dodge did anything to help hold them in place, though.

In reply to Mr_Asa :

Just a regular lifter and rocker arm. Nothing special and they last just fine.

Definitely looking forward to what comes out of this. Glad I could help get it started.

OK......I know nothing.....But.....

could you use Chevy V6 heads ?  or would the welding be the same ?

In reply to californiamilleghia :

Maybe?  I don't know which have the proper bolt spacing though.

90 degree V6 heads have the same head bolt pattern as small block chevy because it IS basically an SBC with two cylinders lopped off... and SBC is pretty darn close to LS IIRC.  Of course, they are based on SBC genes, so not a whole lot better than stock 300 heads.

There are some wackos out there who have put LS heads on a Windsor with some enlarging of the bolt holes.

I do seem to remember some Buick V6 heads of some racing pedigree (NASCAR?) that have the exact bolt pattern, but they are pretty rare.

wheels777 said:

Pete. (l33t FS) said:

In reply to wheels777 :

I hope this comes to fruition because I think that'd be rad as all hell.

Bigger issue is the lack of roller cams. 

I missed this.  Why is this an issue?  And why do you think there aren't roller cams?  Crane, Schneider, and a few others make roller cams.

In reply to Curtis73 (Forum Supporter) :
The SBC 5 bolt pattern is totally different from the LS 6 bolt pattern...LS is actually similar to a Windsor. The GM LV3 on the other hand seems to be the modern equivalent of the 90* V6, although it's also a direct injection LT (Gen V) based engine.so probably not very helpful either. The extra bulk of the cylinder ends there they meet in the middle would probably make the V6 heads no better for this application than chopping V8 heads OOO|O O|OOO anyway though.

californiamilleghia said:

OK......I know nothing.....But.....

could you use Chevy V6 heads ?  or would the welding be the same ?

Chevy V6 heads probably don't flow as well as the Ford heads did.  And Chevy V6s do not share a head bolt pattern with Ford the way LS engines did, because Chevy in the 50s were apparently bore-distortion enthusiasts 

wheels777 said:

Pete. (l33t FS) said:

In reply to wheels777 :

I hope this comes to fruition because I think that'd be rad as all hell.

Bigger issue is the lack of roller cams. 

Assuming that the valve order is different, it's a moot point.  You're getting a billet cam.

If I remember all this right...

Ford 300 bore space is 4.480 with 4 head bolts per cylinder and symmetrical layout

Small block ford is 4.380 with 4 head bolts per cylinder and symmetrical layout

LS is 4.400 and 4  head bolts per cylinder and symmetrical layout

So the LS is actually closer than using say a Cleveland head (which has also been done in iron before). LS heads are also dirt cheap compared to purchasing aluminum fords only to cut them up. And much easier than dealing with cast iron fords. In either case the valve layout. What really tips the scale is the valve layout as mentioned...300 I6 is E/I and so on from the front of engine with the pushrod to drivers side...Opposite of STD small block ford....but the same as the LS layout. Using LS head means no special cam layout also.

Well, this isn't terrifying or anything.  Perfectly normal to just cut up some good heads.  I am completely ok with this and am not freaking out in a corner of my mind.

Yes! Yes! Yes!  Precision level hackery I love it.