johnc S30 build

[mainboyd]

Does anyone happen to know if John Coffey documented his S30 build where he moved the L engine back 6 inches? 
 

He said in a post “The stock L6 engine moved back 6" and down 2" gives a 48F/52R weight distribution with a composite hood and hatch.” In this forum:  

 

When searching for it I was reminded again of the loss. I never knew him but it is still very sad to know he is gone. But his knowledge is still spread out through hybridz for us to learn from.

 

Any info about that specific build would be greatly appreciated. 

[JMortensen]

Never saw pictures of John's, but Cary (tube80z) sent me pics of his mounts that had the engine back 4" maybe 15 or 20 years ago. He might still have them. Not sure if it was lowered. I think you need dry sump or a shorter sump to lower it 2" and not smack the pan on the ground.

[mainboyd]

I’m very curious to how that build went. Like the placement of the shifter or transmission tunnel clearance (was there clearance for the transmission because it was lowered 2”) or how the firewall was fabricated or, what was already mentioned, clearance from the ground for the oil pan. I have so many questions. 
I wish there were pics of at least the final stage of it. 

[JMortensen]

He had a Quaife sequential gearbox so shifter was likely right next to the steering wheel.

[jonbill]

Fwiw, I lowered my engine 20mm and had to grind a little off the oil pan edge and rack mount. so 2" lowering would need some work. 

[mainboyd]

2 hours ago, jonbill said:

Fwiw, I lowered my engine 20mm and had to grind a little off the oil pan edge and rack mount. so 2" lowering would need some work. 

Just lowered and not moved back? 
 

what made you want to drop it 20mm?

[jonbill]

8 hours ago, mainboyd said:

Just lowered and not moved back? 
 

what made you want to drop it 20mm?

Yes, just lowered. Its a diesel block, 20mm taller, and I wanted it to still fit under my strut brace. 

[tube80z]

On 9/22/2021 at 8:33 AM, JMortensen said:

Never saw pictures of John's, but Cary (tube80z) sent me pics of his mounts that had the engine back 4" maybe 15 or 20 years ago. He might still have them. Not sure if it was lowered. I think you need dry sump or a shorter sump to lower it 2" and not smack the pan on the ground.

 

I don't have the pictures anymore but my old 240Z race car also had this mod as I ran under GT-2 rules (first spark plug aligns with front axle centerline).  Ideally you need a dry sump as the oil pump will end up being the part that keeps you from moving the engine down.  If you look at a standard l-series install you can see that it wants to be in the same place as the rack and cross member when you move this far back.

 

So while this gives a much better weight distribution (mine was slightly better but not much 47.8 front) the one thing not mentioned is this makes the car much faster at corner turn-in and gives you quick mid-corner rotation.  I raced with 4 other Z cars at one time and we all had similar setups but my car was generally faster.  The more corners the more this was so.  And I could generally brake deeper than the other cars.  

[JMortensen]

One other aspect which may or may not be pertinent is the transmission bell housing. I was looking at my LS engine and trying to figure out how much ground clearance I needed. I bought a custom oil pan that was shorter, then when I bolted it up I realize that the bell housing hung down about as far as the stock Camaro pan did, so I paid a bunch for a pan that didn't gain me any clearance. Shame on me for not looking at some pics before I ordered the pan.

[mainboyd]

On 9/24/2021 at 1:38 PM, tube80z said:

 

I don't have the pictures anymore but my old 240Z race car also had this mod as I ran under GT-2 rules (first spark plug aligns with front axle centerline).  Ideally you need a dry sump as the oil pump will end up being the part that keeps you from moving the engine down.  If you look at a standard l-series install you can see that it wants to be in the same place as the rack and cross member when you move this far back.

 

So while this gives a much better weight distribution (mine was slightly better but not much 47.8 front) the one thing not mentioned is this makes the car much faster at corner turn-in and gives you quick mid-corner rotation.  I raced with 4 other Z cars at one time and we all had similar setups but my car was generally faster.  The more corners the more this was so.  And I could generally brake deeper than the other cars.  

Man I really do wish I could see this in person or at least see some pictures. 
 

So the first spark plug (front one) was aligned with the front axle. So you were super close to making it a legit front mid engine Z. I think another 6 inches then that would make it possible? Not sure on the exact measurements because I’m just eyeballing it. 
 

That’s actually why I’m interested because I want to do the same. I want to just make sure I know what I’m getting myself into. I have some machining and welding experience for fabricating things. But for the things I know I will run into is the transmission tunnel clearance, ground clearance for oil pan and figuring out how to still switch gears in a manual transmission.

 

If I’m going to move forward on this then I’ll start a new build thread but I would still like to see if anyone can provide any pictures and information on this topic. 

[mainboyd]

On 9/24/2021 at 3:25 PM, JMortensen said:

One other aspect which may or may not be pertinent is the transmission bell housing. I was looking at my LS engine and trying to figure out how much ground clearance I needed. I bought a custom oil pan that was shorter, then when I bolted it up I realize that the bell housing hung down about as far as the stock Camaro pan did, so I paid a bunch for a pan that didn't gain me any clearance. Shame on me for not looking at some pics before I ordered the pan.

 

Oh yea that’s a really good point. I’m glad you mentioned that.