We have started testing some different 402 combinations. Here is a brief description of the results so far:

SDPC 402 using GM Performance Parts LS2 block (Part # 12568950), Callies 4" crank, JE flat top pistons (~11.5:1 CR)

Using GM LS6 CNC Heads (Part # 88958665), a stock LS6 intake, a BBK 80mm TB, and an SDPC Z+ cam - 220/224 @ 0.050 0.551/0.551 lift on a 114 (with 1.7 rockers *** NOTE we were using some custom 1.75 roller rockers, so the lift was actually .567/.567)

With this small cam, HP = 537 @ 5400 and TQ = 564 @ 4600 (almost 500ft/lbs from 3000-6000)

On this setup, we were running a custom vacuum pump. The pump pulled a solid 8-10inHg during the run, and it probably contributed 8-10hp. Unfortunately, the pump broke while tuning our next setup. We expect to have it back in operation for our next round of testing.


We then installed a larger cam, BigStick240 - 240/246 @ .050 .600.600 lift on a 112 (with 1.7 rockers; we were using 1.75 rockers, so our lift was .618/.618).

With this medium cam, HP = 599 @ 6300 and TQ = 572 @ 4800


We then installed a FAST 90 and used a SDPC 90mm TB.

With the FAST 90, HP = 619 @ 6200 and TQ = 582 @ 4800


We have more head/cam combinations to try.


For pics, vids, and more detail, see here.

 

What all would I have to upgrade to put one of these on my car. I currently have all the bolt ons. I am considering putting in one of those bad boys.

 

Are those numbers from an engine dyno?

Mark

 

Fortunately, it is fairly straightforward. You would need to decide about the FAST 90 setup, which cam (wait till do some more testing). There are a couple of harness extensions (cam and knock sensor) that are needed. You would probably want to see about having the chambers opened up as well to be optimal with the 4" bore.

 

Yes.

 

Can't wait to see the number with aftermarket heads on it.

 

It will be interesting. However, these GM LS6 heads are much better than people think. I had them on my 383 and put down 479RWHP with the GrandAm cam over 3 years ago. They have made a couple of improvements on the heads since then. I am hoping the next round to be able to try some heads with a different valve angle.

 

What is the reason for the vaccum pump?

 

 

The ls7 head, I personally would go with the ETP HEADS
I would like some dyno numbers with The ETP 240's
What rods ...........
SDPC putting callies rotating assemblies in now ?

Thanks for the numbers ,a lot of with the c5 guys.
John Sr.

 

When do you expect to do some more dyno runs? I have this short block with 240/246 cam coming from you and don't have the heads yet. Would sure like to see the AFR/ETP comparisions before I buy.

 

This particular motor will be going into a 2001 Corvette and will see a fair amount of track time. Drag racers have been using vacuum pumps for years. On a big block, a good vacuum pump can be worth well over 30HP.

In short, a vacuum pump will help manage crankcase pressure in a more efficient manner while increasing HP and decreasing “blow by”. This can become more important with forced induction or nitrous applications. The addition of a vacuum pump can allow owners more options regarding different ring packages as well as minimize the possibility of oil going the ‘other way’ and contaminating the combustion process.

The primary reason for a vacuum pump is that ring seal, however good, is never absolute. All engines create a certain amount of "blow by" (leakage of compressed fuel and air past the rings into the pan area). The "blow by" airflow creates pressure in the crankcase, the vacuum pump "sucks" air out of the crankcase with its "negative" airflow. The net difference between the airflow being "sucked" out and the airflow being "blown" in by blow by yields vacuum. If the airflow being "sucked" out is less than, or not much more than the air flow being blown in, the vacuum pump is not creating enough "sucked" airflow to eliminate pressure in the crankcase or to create adequate vacuum to not only stop leaks, but to create horsepower.

Typically smaller engines generate less "blow by" and don’t require as "big" of a vacuum pump as large displacement engines (i.e. as displacement increases the function, purpose, and need of a vacuum pump increases). However the addition of low tension ring packages, power adders such as Nitrous Oxide, Alcohol, Blowers or Turbochargers (and the ring and piston types, clearances and modifications that go with those power adders) will increase crankcase pressures requiring either a "larger" pump or to spin a "smaller" pump slightly faster.

Here is a good article regarding vacuum pumps in hardcore racing applications: link

 

The rods in this motor are actually billet Manley. However, we will build whatever you want/need. We just sold 4 short blocks with Callies equipment. But, we can/do use everything Eagle, Compstar, Callies, Lunati, JE, Diamond, etc.

 

What size injectors are you using on the 402's? Would you have long blocks available?

 

The basic formula used for injector sizing is:

HP x BSFC / (# of injectors x .8) = Injector Rating in lbs/hr

* for bsfc use ~.45 for NA in these engines
* the .8 is the maximum duty cycle you want to see

For 600HP, I like to see around 40lbs/hr at our fuel pressure. On our test motor, we are currently using GM injectors 24508208 which flow ~40lbs/hr at our fuel pressure (58psi). I am actually thinking of upping that to a slightly larger injector for growth.

Yes we have long blocks available, and we can talk about an install as well. The shortblocks start aroun $4,000 - $4,100, but can vary depending on the internals selected. Long blocks can really vary depending on intake, heads (especially the hardware on the heads), water pump, etc Let me know if I can help or you need more input.

 

Sounds like a great set up and I really appreciate you posting the dyno results with different configurations of the long block 402.

Just how streetable would this motor be and would it run on 93 octane?

 

That combo should EASILY run on 93 Octane unless he's knocking on 12:1 CR or something, which I doubt.

 

I will be getting the 402 short block installed with ETP 215 heads a mild cam and ls2 intake next week at Jamisons. Then onto having it tuned before the March 18th Corvette Challenge at Carolina Dragway. 2 weeks and I'll have track results for this set-up

Joe

 

I think i just figured out where next year's tax return is going.

Shane

 

Nice numbers And i have to say SDPC has great customer service. Thats where I got my 402 from