• Protip: Profile posts are public! Use Conversations to message other members privately. Everyone can see the content of a profile post.

Semi-DIY Mild Engine Build for FI

Rating - 0%
0   0   0
Joined
Apr 25, 2005
Messages
3,031
Location
Western PA
I've built my fair share and it takes time. I built other peoples maybe more anal than I build my own. Cleaning takes forever and I always tried to convey that to customers, but not sure they ever really understood just how much time it takes. Then there is the assembly process, it takes forever and a focused mind to do it right in my opinion. That being said, I don't miss this kind of work. :biggrin:

Yeah, time is money and a lot of people don't understand what should go into a quality engine rebuild back to OEM or better standards....

The focused mindset is another important aspect. Like I mentioned in this thread, it's very easy to see how distractions can screw up a professional. Heck, I did most of my work late at night when I could minimize wife and kid distractions... but then you also get tired and can make more mistakes that way too.

http://www.nsxprime.com/forum/showthread.php/195472-Negative-review-Mile-High-Acura-Denver-CO?p=1897663&viewfull=1#post1897663
 
Rating - 0%
0   0   0
Joined
Apr 25, 2005
Messages
3,031
Location
Western PA
My shop had some specialized hot water pressure cleaner that cleaned the parts as if you loaded your dishes in a dish washer.

Yup, I thoroughly washed the block and heads with my pressure washer hooked up to my HW heater before shipping them out and then also after they were returned. Everything was then blown out with the air compressor followed up with liberal applications of WD40.
 
Rating - 0%
0   0   0
Joined
Apr 25, 2005
Messages
3,031
Location
Western PA
Miraculously this engine is still working.

I'm glad I kept it 10.2:1 static CR since I'm back to naturally aspirated for the time being. Thinking what to do next since I like to tinker.

Surprisingly it seems as if I drive it more in the winter than the summer. Just have to be careful with the cold summer tires and less traction, but that makes it fun on the streets too.

It's routinely driven in 20F temperatures as long as the roads are dry. The hard part is keeping the road salt off as much as possible and the car somewhat presentable.

I don't notice any piston slap when cold. I probably should have put some 0W30 oil in, but I just take it easy until oil temp is up to around 150F in the pan. The only thing is an intermittent screech on the TB side when the engine is less than 25F out. It does it so intermittently that I can't tell if it's a cam gear rubbing on the inside of a plastic cover (my old covers had marks), or it's the alternator. I don't have the A/C belt or system installed anymore. It goes away when the engine is warmed up. I think it's the cam gear covers and it's just too cold.

View attachment 158717
 
Rating - 0%
0   0   0
Joined
Apr 25, 2005
Messages
3,031
Location
Western PA
I think I figured out why you drive it more during the winter then the summer. [emoji6]

Nice report, thanks Dave.

:biggrin: Yeah, it sounded like a good idea at the time (about 10 years ago)! That was when we lived in hot, humid, SC too.

BUT, I have to say that driving a 2500 lb NSX is worth it. Combined with ~525 WHP this car was an absolute beast - Too much actually. I have to agree with Autowave that 400 WHP is a nice sweet spot for this platform. The next major decision is whether or not I can be happy with a custom ITB setup and get to at least 330 WHP, or go to a simpler turbo arrangement and target 400 WHP.

I'm leaning toward ITB setup with varying-length runners and a custom ram-air intake plenum. Already have the lexan hatch, and my design won't hinder rearview visibility. The ITBs would probably be the following. Not a bad price either:
https://www.atpower.com/products/universal-throttles

They've been around for awhile seem to be a durable product. This is their claim-to-fame:
https://www.atpower.com/why-butterfly
b0c92d7ab76fb9bc570c119e6f875742.jpg
 
Rating - 0%
0   0   0
Joined
Apr 25, 2005
Messages
3,031
Location
Western PA
Been using this as my primary daily for the past few months and thought I'd give a 10k mile update (post engine rebuild) under the following configs:

* 295 WHP OEM intake manifold during break-in and initial use after I'd had the car apart for a few years
* 550 WHP custom twin turbos (the reason for the rebuild)
* 380 WHP ITBs

Redline for all configs was 9k RPM and every drive I take it hits redline at least once!

While a lot of thought, time, and money went into radiusing every edge on the rotating assembly and critical block components, ring gaps, squish, combustion chamber reshaping, oil supply, etc, probably the biggest unknown for me was how the DLC coating would work on the floating piston wrist pins instead of bushing the Ti rods and weakening them. I'm pretty sure I was the first to DLC coat the pins in a NSX engine, and internet research back then didn't bring up any daily drivers using the process either. Well, I'm happy to report no problems at all.

Because of the size, difficulty, and expense, my custom oil filter has only been changed three times after the rebuild (even though I change the oil every 6 months or so). I haven't found any flecks of coating or any indication in the filter medium that the DLC has chipped, so I highly recommend this process as opposed to bushing the small ends of the rods.

This past year I've put the engine back to a more reliable OE configuration with the oil setup and intake. Made another exhaust and will continue messing with active aero. It's therefore mostly been a daily driver for me lately and this platform works best IMO at around 300 WHP. My car is also less than 2600 lbs so the power to weight ratio is entertaining enough on the street. I've put over 80k miles on this thing and its been a great vehicle. So glad I chose this instead of a F355 when trying to decide what to get as a daily driver 17 years ago!

Taking it to a hiking trail this week and getting it dirty after applying a full ceramic coating (glad to have the 4-wheel lift kit):
20211006_094917.jpg
 
Last edited:
Rating - 0%
0   0   0
Joined
Apr 25, 2005
Messages
3,031
Location
Western PA
Seems like all my old photos disappeared, and I've had requests for more info on some of the rebuild, so here's some photos.

Calico DLC-coated Wiseco "small" wrist pins and my gently radiused OEM main caps. This was taken 9 years ago and have held up to significant abuse if you've read the various iterations I've put my rebuild through.

Here's another pic of one of the OEM Ti rods after it was weight-matched for the rest of the rotating assembly. I removed a little material off the rod small ends and rod caps. Just a few grams mostly because of the aftermarket ARP rod bolt weight differences and to balance everything to with 0.2 grams total (pistons, rings, pins, rods, bearings, and bolts). This was before I polished the rods.

All this attention to detail took a lot of thought and time, but it's paid off because I haven't had any problems in 8 years and over 10k miles with this highly stressed motor.
 

Attachments

  • 1.jpg
    1.jpg
    125.9 KB · Views: 7
  • 2.jpg
    2.jpg
    203.5 KB · Views: 7
Rating - 0%
0   0   0
Joined
Oct 30, 2016
Messages
881
Yup! We (meaning mostly @Honcho) migrated the forum from an old single rack server running vbulletin to a xenforo cloud instance, should make maintenance significantly easier going forward as well as provide much better reliability.

I read through this whole thread last night, very interesting stuff in the last few pages that I'd somehow never gone through before. Glad to hear everything is holding up, I think I'm going to try the bushingless rod with DLC pins approach in my engine.
 
Last edited:
Top