Semi-DIY Mild Engine Build for FI

[Mac Attack]

Depending on what needs to be done you may want to reconsider replacing the Main caps?

The broken main cap on SOS website is from my motor. It didn't let go and destroy the anything but it could have.
My motor was a 3.0 stock internals with a Comptech Supercharger. Nothing special. I believe around 325 RWHP.

Later,
Don

Thanks. I'll magnaflux the crank and have all of the journals checked. If they come back OK, I'll TIG out the oil galley balls so I can clean the passageways. Since the main bearing clearances were uniform at 0.0015" and just where I'd want them, and I've done all the work taking the stress risers off of the main caps, I'll still probably leave it as it is. I have a new OEM harmonic dampener, but am considering upgrading to the ATI over the Fluidampr. That should help with main and crank stresses too at elevated power levels.

If the crank is bad, then yes, I'll probably go with the billet mains. I'll probably consider more serious upgrades too, like a stroker crank.

I just saw the spun rod bearing on Dimer's fresh engine rebuild with only 125 miles:
http://www.nsxprime.com/forum/showthread.php/159361-ASM-Time-Attack-CTSC-NSX/page6?p=1729367&viewfull=1#post1729367

It sucks, but it confirms my uncertainty on my rod bearings and spending more time and money to figure it out.

Too big of clearance drops oil pressure to other critical areas of the engine and may also not allow a sufficient oil wedge to form between the bearings and the journals. Too little of clearance is bad for many reasons.

 

[Mac Attack]

ARP rod bolts are in. The block, crank, and rods are going to the machine shop tomorrow.

The block bore will be increased a tad for more piston-to-wall clearance.

The crank is getting magnafluxed and the OEM oil galley balls removed, drilled, tapped, passageways cleaned out, then plugs loctited in. Journal diameters will be measured.

The rods will have the pistons removed, old rod bolts pressed out, new ARP rod bolts pressed in, and big ends measured for roundness and size.

I'm taking all of my rod bearings and getting those measured too. If they are way out of spec or I can't make any of them work, then I need to research aftermarket offerings. Or try the OEM Daido's. I created a separate thread on my bearing findings here to try and get a little more visibility:
http://www.nsxprime.com/forum/showthread.php/176145-Problem-With-New-OEM-Rod-and-Main-Engine-Bearings

I'll also weigh the OEM rod bolt/washer/nut and the new rod bolt/nut to quantify the difference and see if I need to do anything about it (doubtful).

Should be less than 2 weeks at the shop.

 

[mr envy]

ok so I have a c30a that we line bored to accept bearings from a Nissan rb30e if I remember correctly, crank remained untouched but the block and rods were line bored to suit. unsure if this actually helps but may just be another option

 

[Mac Attack]

Thanks for the info.

Wish I had shops more local to me that were familiar with Hondas and Japanese engines.

I've contacted the big engine bearing makers, and am excited about a few prospects. I may be trying out a new test product, in which case I'll send my crank, block, and rods in to their designated machine shop (so they can do whatever they need to ensure highly accurate clearances), and try out their product. At least the shop I just dropped it off at will confirm the problems I was having Hopefully I'll get this project going ASAP.

Reason being, I'll be making the highest torque of any NSX engine out there at the lowest RPM with my compound turbo setup. This places a lot more stress on the bearings.

Dave

 

[Mac Attack]

Hmm, a lot of people looking, but no one posting....

Doing coupled fluid/structure analyses now of crankshaft harmonics, rod distortion, and visco-elastic hydrodynamics. I'd like to keep the OEM oil pump with just slight porting modifications. This will help determine the oil viscosity to use with my final clearances.



On another note, compound turbo design is progressing. Good thing my buddy and I are doing it to his new S4 first :biggrin: The design is simple, but not looking forward to the tune.

 

[RYU]

Hmm, a lot of people looking, but no one posting....

Doing coupled fluid/structure analyses now of crankshaft harmonics, rod distortion, and visco-elastic hydrodynamics. I'd like to keep the OEM oil pump with just slight porting modifications. This will help determine the oil viscosity to use with my final clearances.



On another note, compound turbo design is progressing. Good thing my buddy and I are doing it to his new S4 first :biggrin: The design is simple, but not looking forward to the tune.

Haha! Dave, I don't think half those people (including me) even knows what a compound turbo setup is!

Quick question, been meaning to ask you... For a stock 3.0L @ 100k miles what oil should I be using?

 

[kookoo4nsx]

Dumb question but is a compound turbo the same as a sequential turbo? If not, why? Advantages, disadvantages?
Please, for the little folk.

 

[gsrboy]

Did you find a machine shop near you Dave?

 

[doc_tai]

Compound turbo is very tricky to tune that's what boostlogic tuner told me when I got my car tune

 

[nsxnut]

I like my supercharger. I have the SOS Kenny Bell supercharger with the SOS inter cooler.
At high rpm a turbo can make more power but at Low rpm the supercharger is wicked.
I track my car regularly. Coming out of a corner my car is amazingly quick.

For street use "light to light" I would think a supercharger would be a better fit.

What do I know.

 

[Mac Attack]

Haha! Dave, I don't think half those people (including me) even knows what a compound turbo setup is!

Quick question, been meaning to ask you... For a stock 3.0L @ 100k miles what oil should I be using?

Sorry - too many variables. I monitor oil temps in my pan - do you have a temp sensor that can measure the hottest oil temps? I'm thinking about using Mobil1 Racing 4T 10W40 motorcycle :wink: oil after break-in for street driving in warm ambient temps. Like others have said, the Mobil1 0W-40 oil should be good too.

- - - Updated - - -

Dumb question but is a compound turbo the same as a sequential turbo? If not, why? Advantages, disadvantages?
Please, for the little folk.

Good overview in this link. Compound turbo arrangement is described on the bottom of the first page:
http://www.autozine.org/technical_school/engine/Forced_Induction_3.html

- - - Updated - - -

Did you find a machine shop near you Dave?

Yes, at a place that specializes in European engines... but my arrangement with the bearing company to test their product is based on me sending them my crank and rods so they can ensure the machining and parts conditions are to their highly accurate standards. We're just looking at the rod bearings for now - not the mains.

In the meantime I'm still cleaning old engine parts!

- - - Updated - - -

Compound turbo is very tricky to tune that's what boostlogic tuner told me when I got my car tune

Yes, boostlogic was pretty much the pioneer in this area. However, the trick to seamless turbo integration is the exhaust and intake valves used for the transition. I'll be using OEM valves sourced overseas :smile:

My friend already has his components ready.

- - - Updated - - -

I like my supercharger. I have the SOS Kenny Bell supercharger with the SOS inter cooler.
At high rpm a turbo can make more power but at Low rpm the supercharger is wicked.
I track my car regularly. Coming out of a corner my car is amazingly quick.

For street use "light to light" I would think a supercharger would be a better fit.

What do I know.

Sounds like you have a neat setup that's a lot of fun!

There is no perfect FI system based on performance, cost, and complexity. For our individual needs we need to make compromises. However, I think Dave D.'s twin turbo arrangement using the variable geometry turbos is the best FI setup right now. It's no secret that Aerocharger went out of business awhile back due to a few technical issues and people using them beyond their intended design constraints (overboosting them). However, they've been redesigned, and Dave has been testing them. So far after two years of tracking and I forget how many thousands of miles, it is working great. His torque plateau has the widest RPM range of any NSX turbo setup I've ever seen, and he can easily get to 450WHP on his stock 3.2L if desired.



I just like to do stuff differently. I'm an automotive DIY amateur that's learning as I'm going. Since I'm still slightly hesitant about even the new Aerocharger's longevity, I'd like to try something I don't think anyone else has for the NSX - a compound arrangement. It just so happened that a friend and co-worker of mine is doing the same thing to his newish daily-driver S4. It definitely presents a new and unique challenge.

 

[doc_tai]

Compound turbo is so freaking cool, can't wait to see it finish

 

[Juice]

I know Cody has done a few compound turbos and had plans for the NSX, but cost becomes a factor as well as diminishing returns.

 

[Mac Attack]

... but cost becomes a factor as well as diminishing returns.

I know of a few mad scientists that will engineer, design, and fabricate it themselves. It's just a component cost really... which makes it way cheaper than a CT supercharger, and on par with twin Aerochargers, etc.

Custom headers, Autowave and AMW style ~$2k
Two turbos, ~$3.5k
Sensors: EGT, turbo turbine speed sensors, pressure transducers, ~$500
OEM valves, ~$1k
Misc. piping, fittings, and exhaust components, ~$1k

Already have AEM S2 with dual widebands, and an AEM meth kit with Failsafe.

So, for the cost of pretty much any other FI setup, I can have 300 ft-lbs of torque beginning at 2500 RPMs and end up with 400 ft-lbs at 7500 RPM to limit my wheel HP at 500. Should be a great combination of driveability and peak power.

Dave

 

[RYU]

Your mad scientist ways are always why I read all your threads Dave. I love them.

I do have a question on single/twin turbos vs. sequential vs. compound layouts. I've never been in a turbo car with good throttle response. I'm not a very good driver so throttle response is really something i've grown to love in an NSX NA car. The PD style SC is pretty close but the Centrifugal and Turbo config isn't something i'd be happy with on the NSX. Any comments on how the throttle response would be on a compound turbo setup? It seems like with the two turbos in that layout the throttle response would be even more dulled/insulated or rather like an On/Off switch instead of gradual.

I really wish I could drive Vega$NSX's car on the track. He has the closest thing to a sweet turbo setup i'd love. Fast revving and fun.

 

[Mac Attack]

Good question Regan.

One of the goals to improve throttle response (not turbo lag), is to reduce the hot and cold piping volume as much as possible. That's always been one of my goals, and hard to obtain with the transverse mid-mounted V6 we have. None of the current turbo arrangements out there are ideal IMO. Hence, my reasoning a long time ago to investigate moving around engine bay stuff to better accommodate the turbos:
http://www.nsxprime.com/forum/showthread.php/175370-Twin-Turbo-inside-engine-compartment

I've decided to leave engine mounts and other stuff alone, and just go with the equal-length header/collector design Autowave and AMW have that puts their single turbo right on top of the transmission... except mine will be a compound setup. There is a lot of room there if I relocate all the vacuum stuff out of the way at the back. While not completely ideal, this will yield minimal charge piping volume and restrictions.

No intercooler either... just meth and water so that helps response too.

 

[StmpoRaceProducts]

Good question Regan.

One of the goals to improve throttle response (not turbo lag), is to reduce the hot and cold piping volume as much as possible. That's always been one of my goals, and hard to obtain with the transverse mid-mounted V6 we have. None of the current turbo arrangements out there are ideal IMO. Hence, my reasoning a long time ago to investigate moving around engine bay stuff to better accommodate the turbos:
http://www.nsxprime.com/forum/showthread.php/175370-Twin-Turbo-inside-engine-compartment

I've decided to leave engine mounts and other stuff alone, and just go with the equal-length header/collector design Autowave and AMW have that puts their single turbo right on top of the transmission... except mine will be a compound setup. There is a lot of room there if I relocate all the vacuum stuff out of the way at the back. While not completely ideal, this will yield minimal charge piping volume and restrictions.

No intercooler either... just meth and water so that helps response too.

Dave,

Typically I agree with you on almost every topic but I wanna shed some of my knowledge here. The throttle response really isnt an issue with turbo's because the air in the charge pipe is "traveling THAT FAST".... so fast I wouldn't even be able to provide the data... But I have been shown it to not matter at all.

What does matter is flow and predictability of the air and the longer and straighter the air travels into the air intake of the turbo, the longer and straighter the air travels into the charge pipe, the longer and straighter the air travels into the throttle body, the longer and straighter the exhaust enters the hot side of the turbo, and the straighter the exhaust exists the hot side of the turbo.

I started asking questions when I was around some pretty big HP turbo race cars with 5" charge piping...

My $.02AUD

 

[Mac Attack]

Good point Ross. I haven't been able to drive and compare any turbo'd NSX's, so my input is purely theoretical. Theoretically, the FI setup with the least intake volume AND least restriction should be the best.

Glad to hear from you!

Dave

 

[Mac Attack]

There will be another 3-4 weeks of delays before I can start engine reassembly.

The block is currently being sent to Bensons for sleeving in Idaho.

Piston wrist pins and other parts are being DLC-coated in North Carolina.

Oil pump housing has been ported/blueprinted, and is being sent out for WPC treatment along with the oil pump gear to California.


Should have ditched the C30 a long time ago :frown:

This has got to be one of the longest engine rebuilds ever.

 

[Mac Attack]

Kind of a crummy weekend here in the NW, and I'm fighting a cold, so I stayed outside in the rain away from the family and did a lot of cleaning.

What took the longest was this nasty oil cooler:

I have a ported, epoxy-filled new oil pump housing (soon-to-be-WPC-treated) that is tapped for AN inlet and outlet fittings that completely gets rid of this thing. It's so I can completely relocate the filter and use a bigger custom water/oil cooler for later (when I figure out the turbo header arrangement). But for now, I went ahead and am using the OEM oil pump but with TI_Dave's Accusump connection.

It was a pain to clean this thing since the internal passageways holds a lot of oil. I used about half a can of brake cleaner, a lot of old newspaper and paper towels, and then ended up boiling it in a pot of blue Dawn detergent... followed by a final flush of the oil and coolant passageways outside. Then it was deburred and cleaned up of some of the internals flashing. Finally, painted and cleared with hi-temp paint and reassembled with new O-rings, coolant hose, and pressure sender.

Cleaned engine harness:

And a box of cleaned miscellaneous parts:

Next up is taking apart the intake manifold and working some magic on it.

 

[BATMANs]

u powder coat that oil part?

 

[Mac Attack]

No, just hi-temp ceramic paint for most of this stuff. The Duplicolor 500F ceramic paint is pretty tough - especially when you add a few coats of their hi-temp ceramic clear over it. It's all in the surface preparation :wink:

I have powdercoated a select few parts in my rebuild a nice semi-gloss black though....

 

[Mac Attack]

Been playing with my engine simulator and the compound turbos. If I use an Aerocharger variable geometry turbo on the low pressure side, I should be able to get this awesome torque curve... assuming I don't break my OEM rods:

The black lines are from my dyno right before I took the engine apart.


Since I'm going to be removing the VVIS, I had to make some estimated corrections on the volumetric efficiency in the 5k RPM area. Also, I had to make some estimates on the intake bypass valve opening area and rate.

Cannot wait to get this thing going again. Block and wrist pins should be back this week.

Dave

 

[DDozier]

i am not sure of your exact design but I would check with Aerocharger on the use of their turbo in a compound setup, I do not believe you will be able to move enough air through the Aerocharger for this to work, once the vain controllers have spooled the low pressure turbo the turbine will stall and the second turbo may or maynot spool and if it does the little Aerocharger will be a massive choak point for the high pressure turbo and may cause it to stall. Keep in mind turbine speeds with the Aerocharger are critical, use them outside their intended speed and they tend to destroy themselves from the inside out.

I might be able to help more after I see you plumbing but my only exposure to a compound setup thus far was on a Dodge Cummins using two conventional turbos, we had sized the low pressure turbo too small and ended up with airflow issues when the second turbo spooled. We figured this out by removing the air filter during testing to help eliminate any inlet restictions then the second turbo would stay spooled, but with a filter in place we could not keep it spooled as it would stall from the smaller low presure turbo being a choak point. changed the smaller turbos wheel and housing and everything worked fine.

Dave

 

[Mac Attack]

i am not sure of your exact design but I would check with Aerocharger on the use of their turbo in a compound setup, I do not believe you will be able to move enough air through the Aerocharger for this to work, once the vain controllers have spooled the low pressure turbo the turbine will stall and the second turbo may or maynot spool and if it does the little Aerocharger will be a massive choak point for the high pressure turbo and may cause it to stall. Keep in mind turbine speeds with the Aerocharger are critical, use them outside their intended speed and they tend to destroy themselves from the inside out.

I might be able to help more after I see you plumbing but my only exposure to a compound setup thus far was on a Dodge Cummins using two conventional turbos, we had sized the low pressure turbo too small and ended up with airflow issues when the second turbo spooled. We figured this out by removing the air filter during testing to help eliminate any inlet restictions then the second turbo would stay spooled, but with a filter in place we could not keep it spooled as it would stall from the smaller low presure turbo being a choak point. changed the smaller turbos wheel and housing and everything worked fine.

Dave

Hi Dave, good to hear from you and I appreciate your offer.

However, on the design I am using, the Aerocharger won't be a choke point. I have intake and exhaust valves enroute overseas from an OEM supplier in order to accomodate this arrangement:

That's why I said in my previous post that I had to make some assumptions on valve cracking dP and opening rate... and potentially why I have a big dip in mid-range torque. I won't know for sure until I fab everything up and actually test it.

I would also like to make everything as simple and passive as possible. I also have tried to make this a "fail-safe" design in case there are issues with the vain controller, exhaust valve, and intake valve sticking. One of the ways to do this was complicate it a bit more with BCSV, wastegate, etc.

Glad to hear you've had experience on compound setups - now I know who to contact first when I get ready to tune it!

Dave