I have built a way out there engine....So far mainly on my own.
As it IS my last and only real serious engine build and done as no one I could find has ever done one this way and there was/is none I could find like it I felt I had to try it myself.
ALL the things I could read and all the advice from all of the people I thought knew their stuff led to this.
But as I near the finish line I received even finer details on the TPI set up and in going over all the details of this nearly finished engine with Adam a member of Speedtalk as NewbVetteGuy and he expressed major concerns of it being a knock monster…
He brought up the DCR (the first I heard of this) and feels I may have a big problem. But:
https://www.gofastmath.com/compress...atic-and-dynamic-compression-ratio-calculator
It comes up with: STATIC Compression Ratio: 9.31:1 and DYNAMIC Compression Ratio: 8.33:1
So at this point I am scared to move until I can feel it will not blow up.
Both he and I have posted on SpeedTalk and I have done the same on thirdgen Camaro.org.
So far no one has been any real help.
In this case this build started as a 350 in 2004, and is at last being finished. But I did a number of upgrades.
So here are the current details:
Vehicle: 1993 G20 van -heavy box. Some towing.
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.
Engine:
1990 SBC OE Roller Block - 30 over bore
Not decked (checked and ruled straight, heads too) but supposed to be .010" piston-to-deck clearance (I believe)
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. Set 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.
Top ring wide gap as per advice of KB piston tech support.
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 (I know worthless rollers)
Head Gasket: A felpro gasket that came in a rebuild kit with a 0.045" compressed thickness
Lifters: Rhodes Roller VMax lifters
Cam is from Oregon Camshaft #806 roller cam:
Adv duration: 265/270 @.006 206/213 @ 0.050": lift: 413"/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 an 87 Corvette TPI intake and have a few different TPI MAF PCMs; the plan is to enable Lean Burn mode at highway cruise. (16.5 AF target at cruise)
Injectors: Toyota Tundra trucks from 2000-2004 came with 12 hole Denso injectors @ 250cc;
Real Cold Air Intake air box getting air from behind head lights.
Stock cast iron exhaust manifolds. Considering 1.5 Tube headers.
I plan to run lots of EGR by electronically controlled system. Both to handle the lean burn and add in MPG, and even see it engine can be run with more throttle lessing pumping losses.
And perhaps water injection...Veri-ject system or NOS injection system with under the main injectors…injectors.
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 tires match factory tire wheel diameter.
Many tests have shown me factory V6 and V8s can get very good MPG at 1500 to 1800 RPMs, like 27 to 32 just by driving at those RPMs, speeds are 50 to 60MPH in their top gear.
I plan on adding second overdrive to get a great 5 gear so on paper my Van will be able to run at 1600RPMs and be doing 70/80MPH.
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 reads like a very high knock risk situation; and we haven't done all the calculations, have run Dyno 2013 got great numbers…planning using PipeMax that would look at the extra cylinder pressure from the TPI intake...also call out best headers.
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 this is a good to go or that I will not need to make major changes to fix this potential knock monster engine + vehicle combination?
Commits and advice??
Rich
As it IS my last and only real serious engine build and done as no one I could find has ever done one this way and there was/is none I could find like it I felt I had to try it myself.
ALL the things I could read and all the advice from all of the people I thought knew their stuff led to this.
But as I near the finish line I received even finer details on the TPI set up and in going over all the details of this nearly finished engine with Adam a member of Speedtalk as NewbVetteGuy and he expressed major concerns of it being a knock monster…
He brought up the DCR (the first I heard of this) and feels I may have a big problem. But:
https://www.gofastmath.com/compress...atic-and-dynamic-compression-ratio-calculator
It comes up with: STATIC Compression Ratio: 9.31:1 and DYNAMIC Compression Ratio: 8.33:1
So at this point I am scared to move until I can feel it will not blow up.
Both he and I have posted on SpeedTalk and I have done the same on thirdgen Camaro.org.
So far no one has been any real help.
In this case this build started as a 350 in 2004, and is at last being finished. But I did a number of upgrades.
So here are the current details:
Vehicle: 1993 G20 van -heavy box. Some towing.
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.
Engine:
1990 SBC OE Roller Block - 30 over bore
Not decked (checked and ruled straight, heads too) but supposed to be .010" piston-to-deck clearance (I believe)
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. Set 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.
Top ring wide gap as per advice of KB piston tech support.
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 (I know worthless rollers)
Head Gasket: A felpro gasket that came in a rebuild kit with a 0.045" compressed thickness
Lifters: Rhodes Roller VMax lifters
Cam is from Oregon Camshaft #806 roller cam:
Adv duration: 265/270 @.006 206/213 @ 0.050": lift: 413"/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 an 87 Corvette TPI intake and have a few different TPI MAF PCMs; the plan is to enable Lean Burn mode at highway cruise. (16.5 AF target at cruise)
Injectors: Toyota Tundra trucks from 2000-2004 came with 12 hole Denso injectors @ 250cc;
Real Cold Air Intake air box getting air from behind head lights.
Stock cast iron exhaust manifolds. Considering 1.5 Tube headers.
I plan to run lots of EGR by electronically controlled system. Both to handle the lean burn and add in MPG, and even see it engine can be run with more throttle lessing pumping losses.
And perhaps water injection...Veri-ject system or NOS injection system with under the main injectors…injectors.
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 tires match factory tire wheel diameter.
Many tests have shown me factory V6 and V8s can get very good MPG at 1500 to 1800 RPMs, like 27 to 32 just by driving at those RPMs, speeds are 50 to 60MPH in their top gear.
I plan on adding second overdrive to get a great 5 gear so on paper my Van will be able to run at 1600RPMs and be doing 70/80MPH.
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 reads like a very high knock risk situation; and we haven't done all the calculations, have run Dyno 2013 got great numbers…planning using PipeMax that would look at the extra cylinder pressure from the TPI intake...also call out best headers.
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 this is a good to go or that I will not need to make major changes to fix this potential knock monster engine + vehicle combination?
Commits and advice??
Rich
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