Is this a Knock monster?? OR??

Vehicle: 1993 G20 van -heavy box.

Goals: Loads of low-end towing torque and the best possible MPG. There's a LOT of focus on fuel economy, as you'll see.

Running 57 Camaro/Corvette TPI on:


Engine:
1990 SBC OE Roller Block -> 30 over bore
Not decked but supposed to be .010" piston-to-deck clearance (I belive)
Machined 400 crank with 5.565" 400 rods
Older KB hyper D-dish pistons (M9890-30) -I couldn't find this piston but they look identical to the KB102-030, so I'm guessing -18cc dish. bought 2/12/2004

As far as I know stock type rings…SEA 251K -.030 Ring Set (Premium) bought 2/12/2004

Total Seal second ring

The piston top, combustion chamber, and intake and exhaust valve have all been Ceramic thermal barrier coated.

Piston skirts Teflon coated.

64cc (I think actually 65.3cc) Swirl port heads #14102193 1.94" / 1.5" valves; with good valve guide seals to keep oil out of the chamber.


1.5 ratio roller-tipped rockers

Head Gasket: A felpro gasket that came in a rebuild kit with a 0.045" compressed thickness

Rhodes RollerVMax lifters


Cam is from Oregon Camshaft #806 roller cam:
Adv duration: 265/270 @.006 206/213 @ 0.050": lift: 431"/428", LSA: 114, ICL: 110
9.25:1 static CR

Running Rhoads V-Max roller lifters at 10% reduction so at low rpms she will be:

185.4/191.7 Lift 371.7/385.2 lobe sep. 114 = torque peak should be right around 1800.


Intake: Will be running a 87 Corvette TPI intakes and a few different TPI MAF PCMs; the plan is to enable Lean Burn mode at highway cruise. (16.5 AF target at cruise)


Real Cold Air Intake air box getting air from behind head lights.

Stock cast iron exhaust manifolds.

I plan to run lots of EGR and perhaps water injection...


Rear Gears & Transmission:

343 rear gears


Rebuilt 4L80e out of a motorhome and a US Gear Dual Range overdrive (was Doug Nash) As a second overdrive -> I have calculated a 1,600-1,800 RPM highway cruise @ 75 mph with the 4L80 in OD and the US Gear in OD with the 343 rear gears and18”Wheel and tire diameter.


Questions / Concerns:
What's the safe "guideline" for the DCR of this motor and what should I do to minimize detonation risk?


But I am told that It sounds like a very high knock risk situation; and we haven't done a calculation using PipeMax that would look at the extra cylinder pressure from the TPI intake...

I have got all sorts of options for how to reduce the dynamic compression or knock risk, but which are the right ones?


Just pull timing from the tune where it tends to knock? I plan on running stock PCMs with Knock sensors. Will they pull enough?


I hope to not need to make major changes to fix this potential knock monster engine + vehicle combination?

Rich

 

With a wider LSA the dynamic is probably going to be relatively high. Starting with 9.25 static is a bit of an advantage. Stock TPIs were generally 9.5 static and had LSAs in the 109-117° ranges. With EGR it might get by, but will also probably like to have cooler heads.