3.6L ScienceofSpeed Engine (NA Stroker)

[Track Addict]

...I imagine your stroker is similar to Jon Martin's 3.8L NA i've driven...
God, I want a built NA motor...

Last time I talked with Jon, the numbers laid out that he actually had a 3.9 litre engine :wink:

The build is going amazing and with that power/weight ratio you are sure going to enjoy that car a ton Shawn. I can't wait to compare your car with my NA ITB stroker NSX when I have it built.

 

[Ponyboy]

The build is going amazing and with that power/weight ratio you are sure going to enjoy that car a ton Shawn. I can't wait to compare your car with my NA ITB stroker NSX when I have it built.

Thanks, bro. I hope yours is even better!

I mentioned the switch to a 4.06 final but really, the only big thing to add is a sequential with the Geartronics pneumatic control. That would be fun.

 

[Track Addict]

Thanks, bro. I hope yours is even better!

I mentioned the switch to a 4.06 final but really, the only big thing to add is a sequential with the Geartronics pneumatic control. That would be fun.

Better!? Naw, it'll just be mine. I have been following your build a long time. I will hopefully get to see you at NSXPO

 

[RYU]

I will hopefully get to see you at NSXPO

+1

one of the few cars I want to see at XPO!

 

[BATMANs]

BTW, I heard that the stroker kit has a short engine life. Has someone blown their engine with a stroker?

 

[Ponyboy]

Better!? Naw, it'll just be mine. I have been following your build a long time. I will hopefully get to see you at NSXPO

Unfortunately not this year. We have a newborn (7 months), I have a big load of school work, and changing careers. But I will be at an NSXPO at some point in the future.

And if yours isn't better than my engine then we aren't properly building on the foundation of present knowledge to produce better results. Hint: "coat all the parts", bump compression a bit, and use race fuel.

+1

one of the few cars I want to see at XPO!

Someday, I'll be there! Maybe COTA?

BTW, I heard that the stroker kit has a short engine life. Has someone blown their engine with a stroker?

References on short engine life for stroker?

 

[BATMANs]

.....References on short engine life for stroker?

Eddy NSX who is close friends to Jon Martin told me so about 2 years ago.

I was surprise to hear that. Only thing I can assume (based from my 2 piston engine builds) are that there was shortcuts like skipping out on the balance and ATI harmonic pulley.

 

[Ponyboy]

ICBW, but IIRC a 3.8-9 is on the edge of being out of conservative rod ratio. Greenberet conducted some really good research on the mathematics of the issue.

Anecdotally, I've heard of some people (three?) with problems in the early versions of the stroker packages. However, consider that these are aftermarket built engines, that there are "teething problems" with every new performance upgrade, and that maintenance and use are generally unquantifiable variables when used as comparison from one to another.

But I, admittedly, don't have complete information so YMMV.

 

[BATMANs]

I took a quick glance at the 911 and GTR redline since their displacement would be similar to the NSX stroker kit.

Unless I'm missing something here they are 1k less on the redline than a NSX is at.

So if that is the case, should a stroker NSX be limited to 7200RPMs?

Also, I assume that (due to cost) most of the strokers for the NSX are using the heavier steel con rods instead of the upgraded Ti con rods.

 

[Ponyboy]

piston velocity, tensile strength of materials, bearing load limits, con-rod ratio, etc are all variables that can determine an engine's redline and one can look at the range of similar displacements as a general reference but, IMHO, not a specific guide.

Consider the K20 and F20.

 

[RYU]

Not sure if this is public knowledge but the 3.8L "Jon Martin" stroker was loosely based on the stroker kit for the B series engines. The concern as Shawn mentioned is piston speed. IIRC there is a theoritical upper barrier of piston speed to not exceed. The 3.8L stroker exceeded this theoretical barrier at the stock NSX redline.

I've spoken to JM about this in length and I'm of the belief that if he and I were to build another stroker for my car i'd keep it closer to 3.5-3.6L to gain more RPM range based on how I drive my car. Lots of variables to consider though and it's all about how much money you want to throw at it.

The biggest plus side for me is I can still get a stroked motor to pass smog w/o any issues just like my CTSC. I can't do that with ITBs or a Turbo.

 

[Track Addict]

Congrats on your newborn!

 

[BATMANs]

A Stroker in the 3.5 range is basically one that doesn't require boring?

 

[RYU]

A Stroker in the 3.5 range is basically one that doesn't require boring?

If piston speed is your concern then you'd want to bore, not increase stroke length. I don't recall how much displacement can be achieved from just a bore. Hopefully someone can chime in.

 

[Ponyboy]

IIRC, 3.4L is as far as you can go w/o boring. So hypothetically, you can go as far as another .5L via boring. Specifically, I know the mm range available is 90-95mm if you can re-sleeve. I don't think you can re-sleeve a 97+ bore because of the FRM material.

 

[RYU]

In a perfect world i'd love to run a high compression engine, max bored chambers, on the stock crank. However, our gas in CA sucks and E85 is surprisingly tedious to get to.

 

[Ponyboy]

Chris at SOS said we could get close to 400rwhp via ITBs and e85.

That was a few years ago when e85 was all the rage. We have 5 stations that carry it still. I think I made the right decision.

I'm surprised e85 is that difficult to get in Cali.

 

[Ponyboy]

Maintaining the battery.

<iframe width="560" height="315" src="https://www.youtube.com/embed/4mkXo05kE3Q" frameborder="0" allowfullscreen></iframe>

 

[Track Addict]

OMG that sounds amazing. I am loving the throttle response that your car has. It's a VTEC symphony.

 

[BATMANs]

Chris at SOS said we could get close to 400rwhp via ITBs and e85.

That was a few years ago when e85 was all the rage. We have 5 stations that carry it still. I think I made the right decision.

I'm surprised e85 is that difficult to get in Cali.

And sans E85?

 

[naaman]

I'm at 369rwhp and weighing a little over 2700lbs.

Dude... That's gotta be a blast.

My Chevy is putting 361 at the wheels, and it's "tickle the pickle" fast, but it's also 800 lbs heavier than your car... That NSX must be a total blast.

 

[BATMANs]

That's a low to mid 11 second car right there.....

 

[RYU]

those numbers are awesome. I'm right around that same wHP and about 85lbs more than your car. I have to deal with the additional heat and the parasitic drag. Damn you CARB!

I should really start thinking about my NA build but hope to incorporate an intake plenum and spend a lot of time designing a scavenging exhaust system. NAs requires so much more though (AND $$$) per horsepower lol

 

[Ponyboy]

Dude... That's gotta be a blast.

Well, it ain't a snooze fest. I wish I drove it more.

I should really start thinking about my NA build but hope to incorporate an intake plenum and spend a lot of time designing a scavenging exhaust system. NAs requires so much more though (AND $$$) per horsepower lol

I think you're in the hp sweet spot for the NSX's chassis. And all of the thought and effort into getting solid NA hp/tq results is part of the attraction (for me anyway). There is a company (Hogans) in Santa Maria, CA that has experience making NSX intake manifolds. And they'll make it to you spec (where you want your tq peak) as well. I can't remember the guys name but I talked with a vendor from LA years ago about making a custom set of headers. At the time, he was making headers for various Honda Indy teams. I spoke with John at Hytech and he offered to design a complete exhaust system (headers and exhaust) with a X pattern exhaust. I'd bet you could come really close to ITB performance with the big single intake manifold.

 

[naaman]

Well, it ain't a snooze fest. I wish I drove it more.

I'll be happy to rack up some miles on it for ya.