Semi-DIY Mild Engine Build for FI

[Mac Attack]

I've been waiting on my electronic torque wrench calibration tool (should have bought one a long time ago), and my new replacement "oil breathing covers" according to Acura. During disassembly, I removed these to clean behind them. The covers have retaining tabs that bend up to the bolt heads and probably would have broken if I tried to reuse them. They're cheap to replace (about $15 total).

Torqued to around 10 lb-ft and staked:

Next up, checking the main bearings for clearance. Of course, I inspected the bearings first and noticed the ends had flashing that would have protruded into the crankshaft journal:

Jeez, I could really feel this with my finger. I pulled up my old disassembly pictures, and sure enough, there was significant bearing wear in this interface area. So, I took out 600 grit sandpaper and gently filed off these ridges working in the direction from the bearing to the edge. Repeated with 1000 grit. Not much, just to take off this ridge. Don't touch the edges as to not affect bearing crush, and don't touch the bearing surface. I'm a little disappointed with the OEM bearing quality....

After gently sanding the ridges off (this is becoming a major theme in this build), I thoroughly cleaned them and then inserted them in the caps or block. I checked to ensure the oil holes were correctly lined up, the tangs were the right size, and the bearing edge protrusion for bearing "crush." These things don't have any crush to them - the edges came exactly to the main or block edges.

After cleaning and installation in the block and caps, I went to insert my dial bore indicator to measure the main bore... and scratched the crap out of the first pair of bearings with the chrome balls. I was a little pissed, and glad I had bought extra bearings (a few different sizes too just in case). They're cheap. At this point, I had to file two new bearings and clean them up, and made the decision just to go ahead and Plastigage the mains.

Dry bearings and crank. Don't rotate the crankshaft. Apply the plastic gently:

Gently tap the mains into place. I did three different torque passes according to the OEM sequence in the SM on each of the top and side main bolts leading up to OEM spec. I'm reusing OEM main bolts for the same reason I gave above on the OEM connecting rod bolts. The bolt threads and heads were oiled with 30W according to the SM. Technically, you should chase all of these block threads to clean them up before detail block cleaning, but I visually checked mine and they were perfect.

Carefully disassemble and check out the plastigage pattern (want it uniform), and size (SM spec is between 0.0009 to 0.0019"). All of mine are between an estimated 0.0015 to 0.0017". Good enough. :

Next up is to clean the plastigage off of the main journals and bearings, lay the crank in, and check rod bearing clearances. I'm not even going to take a chance scratching the aluminum (I assume) bearings with the dial bore indicator to calculate clearance. Just going straight to the plastigage.

 

[RYU]

are you going fo sell this car someday Dave?

 

[Mac Attack]

Why? Have you noticed a fatal flaw in my engine work?:wink:

After 9 years and considering all the time spent on it, I doubt I'll ever get rid of her.

I would like to chop the roof about 2 inches someday. I have about that headroom with a helmet now and OEM seats. 2 inches off the roofline will make this car look so much better.

 

[RYU]

just the exact opposite. with all the good work you've put into her i can't imagine you'd ever sell.

 

[sparky]

I've never heard of "oil breathing covers before"? curious - what's under them and what they do exactly?

 

[Mac Attack]

I've never heard of "oil breathing covers before"? curious - what's under them and what they do exactly?

Good question. I've forgotten the exact oil passageway routes in the engine, but I'll have to take a look in the SM sometime. It helps to have all the parts readily available (like the heads) when you're tracing oil and coolant paths.

This is what was under mine when I took it apart... a little crud:

Also, I find it strange that even SOS doesn't remove theirs and clean them out or replace the covers in their high $ builds. The below pic is from one of their 3.5L builds:
http://www.scienceofspeed.com/newsletter/111611_3.5L_engine_build/

It even looks nasty and rusted on the outside whereas mine looked new and clean. Imagine what could be on the underside of those covers





Anyways, time to install some pistons. I cleaned all of the plastigage off of the crank and main bearings, applied Clevite77 bearing lube to the main bearings and main journals and thrust bearings, inserted the crank, then attached the caps and torqued them to around 20 ft-lbs on the top and sides. Just to hold the crank in while I install the pistons.

EDIT: Forgot to note that the new OEM rod bearings (unlike the new OEM main bearings) did not require any work to them. I just thoroughly cleaned them, inserted into the rods or caps, and checked for tang fitup, oil hole fitup on the piston side, and bearing crush protrusion.

Since it was a quick check, I also checked for crank end play per the SM.

I wiped down all of the cylinder bores again with 30W oil, rotated the crank to BDC for the particular piston to be inserted, aligned the piston ring gaps per Wiseco's recommendation (decided to use their recommendation instead of Honda's at the last minute), put covers over the connecting rod bolts to protect the crank when inserting, lubed the piston skirts with 30W oil, and shoved the first piston in with my ARP tapered piston ring compressor and my thumbs :smile: Pretty easy.

Laid a strip of Plastigage at the center:

Then applied a bit of oil to the rod bolt threads and nut faces since these are just torqued a small amount and primarily through TTA. The oil should add a bit more clamping load while it is torqued to 14 ft-lbs since thread friction is reduced. Torqued the rod nuts to 14 ft-lbs and then rotated them 95 degrees according to the SM:

And this is where I ran into issues. In a nutshell, only three of my rod bearings measured within spec at ~0.0018, 0.0019, and 0.0016". Spec is between 0.0016 to 0.0024".

The out of spec ones were approximately 0.0008, 0.0009, and 0.0028". I think I know what caused the extremely small "measured" clearances - the rod must not have been pulled all the way to the crankshaft when torquing down the rod cap. I probably accidentally overly squished the plastigage on the cap side trying to pull the rod up to the cap. Damn, why didn't I think of that earlier when I first encountered a 0.0008 clearance It's also pretty easy to accidentally turn the crank when you're torqueing the rod caps, thus "smearing" the plastigage and making it look like a smaller clearance then what is really there.

Every single rod was removed with old green bearings on the top and old brown bearings on the bottom. So that's what I bought as replacements from Acura. The block and crank hieroglyphics were deciphered to be green or brown bearings too - just a different mix of brown/brown for a few of the rods. The green bearings are nominally 0.0001" thinner than the browns, and I wanted to err on the larger clearance than the smaller clearance. That's another reason why I went with the green/brown combo on each rod.

I still have the matter of too large of clearance on piston #6. I'll put in an order to Acura tomorrow for two blue, two black, and at least four red bearings. Take this for what it's worth, but at least it matches the bearing size trend from the SM:

Rod bearing thickness by color
Blue ....0.0594”- 0.0593”
Black ...0.0593”- 0.0592”
Brown .0.0592”- 0.0591”
Green ..0.0591”- 0.0590”
Yellow .0.0590”- 0.0589”
Pink ....0.0589”- 0.0587”
Red .....0.0587”- 0.0586”


A minor setback, but at least I can try to redo the two extremely small clearance rods tomorrow and test my hypothesis.

 

[sparky]

ah - so we need oil breather covers to hide "a little crud" :smile: curiouser and curiouser !

 

[L_RAO]

Can I get some cliff notes:

What turbos (brand, size, trim) are you running, Mac?

 

[Mac Attack]

Can I get some cliff notes:

What turbos (brand, size, trim) are you running, Mac?

I still don't know yet. My first priority is to get it back together with the OEM intake manifold, injectors, and ECU running it N/A. Do a few warmup and heat cycles for the bearings and new valvesprings/retainers. After a few oil changes, then I'll go out and beat on it to seat the rings at high cylinder combustion pressures.


I've thought about the optimal turbo arrangement for me the past few years. A few of my ideas are in this thread:
http://www.nsxprime.com/forum/showthread.php/175370-Twin-Turbo-inside-engine-compartment

It ranges from Autowave-style headers and collector to sequential turbos sitting above the tranny, to a more conventional twin arrangement underneath the trunk using the Aerodyne variable-geometry turbos, to a more customized setup that uses independent IM's and throttle bodies and turbos for each bank.

At this point, I'll just be happy getting it running again!






Ordered a bunch of new rod bearings today. Hopefully I can try to redo the two tightest bearings tonight though to confirm my hypothesis. There's no way they could be that tight given the bearing sizes I removed from the engine and the fact there was no visible rod bearing wear.

 

[L_RAO]

Well, don't mean to throw you off too much, but since you have the motor apart, have you considered getting some of the critical components WPC treated? I'd consider the oil pump gear/housing, main bearings, piston wrist pins, piston skirts and rings at the very least.

 

[Mac Attack]

I have considered WPC treatment, but personally (and I have a materials engineering background), I'm skeptical of the claims and limited published data. For the cost, it just didn't make sense with my particular build.

Also, treating main bearings should have no impact on performance since the crank rides on a hydrodynamic oil wedge. Treating piston rings beyond the existing ring technology doesn't make sense to me due to wanting those to wear and seat correctly. My piston skirts are already xylan-coated which is "good enough."

For surface treatments, DLC are the best, but those are more expensive too. It's common to DLC treat piston wrist pins, etc.

Honestly, if you are trying to reduce friction losses as much as possible for your N/A build, I would go with the thinnest lowest tension piston rings as possible and beef up your crankcase evacuation system to compensate for the additional blowby. Ring tension is one of the largest source of friction losses in the engine. For example, The crankshaft "stiction" force due to the main bearings was less than a ft-lb of torque to overcome on my engine. When I installed all of my pistons, the "stiction" force took about 9 ft-lbs to overcome. Some of that was due to rod bearings and wrist pin friction, but most of that is due to the piston rings and wearing on the newly-honed bores. That's why I had the new crankshaft pulley bolt installed in the picture above - so I could measure all of this as I assembled it :wink:

The TB itself is another loss. Direct drive gears would reduce the friction losses if you optimize the pitch and gear mesh, but those would be expensive, awkward, and gains in friction would be overcome by the additional MOI during acceleration.

MY $0.02!

Dave

 

[L_RAO]

Mac,

I understand where you're coming from. Have you tried asking them for specific information that, I think if it came from you (they would recognize the nature of question), they would be willing to divulge more "technical" information.

I looked into DLC as well, and came into 2 problems...(1) the DLC coatings, at least those applied by non-OEM providers, do not seem to last (stay on) very long, and (2) most DLC providers are too busy dealing with racing teams to deal with a sub-$500 order such as much.

I have considered WPC treatment, but personally (and I have a materials engineering background), I'm skeptical of the claims and limited published data. For the cost, it just didn't make sense with my particular build.

Also, treating main bearings should have no impact on performance since the crank rides on a hydrodynamic oil wedge. Treating piston rings doesn't make sense due to wanting those to wear and seat correctly. My piston skirts are already xylan-coated which is "good enough."

For surface treatments, DLC are the best, but those are more expensive too. It's common to DLC treat piston wrist pins, etc.

Honestly, if you are trying to reduce friction losses as much as possible for your N/A build, I would go with the thinnest lowest tension piston rings as possible and beef up your crankcase evacuation system to compensate for the additional blowby. Ring tension is one of the largest source of friction losses in the engine. For example, The crankshaft "stiction" force due to the main bearings was less than a ft-lb of torque to overcome on my engine. When I installed all of my pistons, the "stiction" force took about 9 ft-lbs to overcome. Some of that was due to rod bearings and wrist pin friction, but most of that is due to the piston rings and wearing on the newly-honed bores.

The TB itself is another loss. Direct drive gears would reduce the friction losses if you optimize the pitch and gear mesh, but those would be expensive, awkward, and gains in friction would be overcome by the additional MOI.

MY $0.02!

Dave

 

[Mac Attack]

I do think that their surface treatment process has the biggest benefit in strengthening the material due to the micropeening effect. It would be beneficial for transmission gears, oil pump gears and such.


Just went to their website again... They have leakdown results for a Harley with less than 1% cylinder leakdown! On an otherwise engine in good shape with perfect valve sealing, most cylinder leakage is through the ring gaps - not through the rings/cylinder wall interface. If the engine is at the correct temperature the ring gaps were set at, then they should be almost closed and you will have great leakdown results. I'll bet my non-treated WPC engine will have less than 1% leakdown too at hot conditions if I were to test it.

It's targeted marketing like this and the lack of any data (just basically pictures on their website) that makes me stay away from it and keep with what has been proven over and over. I know they are trying to sell a product, but.... That's why I'm not in sales!

 

[Mac Attack]

I decided to think about what I could be doing wrong to screw up the rod clearance measurement.

Since the rods can twist a bit while torqueing them, I stuck in feeler gages to remove any slack while torqueing the rod nuts. Also, because this isn't an inline engine and has splayed crank journals, I clamped a crankshaft counterweight so it couldn't rotate while I was pushing down a bit on the crank while torqueing the rod nuts.

You can see this in the picture below. Together with making sure the rod caps aren't pulling up the pistons when torqueing them down, it should eliminate any unnecessary Plastigage squishing and giving false readings that indicate less clearance than there really is.

Regardless, I have thinner rod bearings coming in from Honda in a few days. I would rather run on the looser side of the tolerance range than the tighter side. So, three of my pistons are in for good, and those rod clearances are 0.0018", 0.0019", and 0.0020".

Unfortunately, having to redo three of the pistons to ensure clearance is eating into my safety margin for OEM rod bolt longevity :wink: It's a common misconception that you need higher strength rod bolts when you increase power. That's not the case. Only if you increase piston/rod weight or engine speed should you really consider higher strength rod bolts. I've lightened the reciprocating mass and I'm keeping redline at 8000RPM so I should be good.

 

[MetalSpikeRacing]

Hey, Did you do billet main caps?

 

[BATMANs]

I did. I don't think he did.

 

[Mac Attack]

Hey, Did you do billet main caps?

No. I have some pictures of the work I did to the OEM main caps and my rationale to strengthen them on the previous page though.

With the billet mains, you need to do a line bore and then perhaps get into custom bearings. For my 500WHP goal and the work I did to the OEMs, I think I'll be fine.

Dave

 

[L_RAO]

Mac,

Here's a research paper from Honda R&D discussing their findings with the WPC treatment:

https://www.hondarandd.jp/point.php?pid=714&lang=en

 

[MetalSpikeRacing]

Ok, Just read it.
So, for what you explain its a hard decision.
Sounds like it would be good insurance to change them, The machine work sounds to be at around 200-300 bucks + the billet caps them selves.
But the again, everything seems to be under risk. Even the crank and rod caps too!!
...
Im like you, I wont rev high and Im only looking for 500whp.
But if a cap goes on me after doing all this work on fresh engine build, that would be game over for me. Ill just move onto something else.

 

[Mac Attack]

Mac,

Here's a research paper from Honda R&D discussing their findings with the WPC treatment:

https://www.hondarandd.jp/point.php?pid=714&lang=en

Thanks,

I applied to become a member so I can read the full paper. My application status is under review :smile:


It's interesting though. Per the overview you linked, the peening and microscopic dimple formation during the WPC process helps create pockets where oil can remain and keep everything lubricated. That was one of the same benefits listed on WPC's site. Particularly for piston walls and rings though, your 2nd ring is a combination of compression control but primarily acts as an oil scraper function to scrape oil off the cylinder walls as the piston moves down.

The ring shape and material, wall honing, etc are all proven packages that have come from decades of research and real-world application. The WPC treatment article from Honda was written back in '99. Since it is relatively cheap, and has the benefits claimed, I wonder why Honda hasn't used this in their high-performance applications (NSX, S2000, motorcycles, snowmobiles, etc) since then?


Did you treat the cam saddles on the heads like you did the cam caps?

Dave

 

[L_RAO]

WPC is actually used in OEM applications by Honda, for certain on the Fit piston skirts. I think it comes down to a logistics issue with their various suppliers. There may also be some bean-counters involved.

I did not treat the saddles; the main guy at WPC said that the material is a PITA to get out of all the little crevices and holes in the cylinder heads.

Of course with the K-series the saddles are separate from the head...

Thanks,

I applied to become a member so I can read the full paper. My application status is under review :smile:


It's interesting though. Per the overview you linked, the peening and microscopic dimple formation during the WPC process helps create pockets where oil can remain and keep everything lubricated. That was one of the same benefits listed on WPC's site. Particularly for piston walls and rings though, your 2nd ring is a combination of compression control but primarily acts as an oil scraper function to scrape oil off the cylinder walls as the piston moves down.

The ring shape and material, wall honing, etc are all proven packages that have come from decades of research and real-world application. The WPC treatment article from Honda was written back in '99. Since it is relatively cheap, and has the benefits claimed, I wonder why Honda hasn't used this in their high-performance applications (NSX, S2000, motorcycles, snowmobiles, etc) since then?


Did you treat the cam saddles on the heads like you did the cam caps?

Dave

 

[Mac Attack]

Ok, Just read it.
So, for what you explain its a hard decision.
Sounds like it would be good insurance to change them, The machine work sounds to be at around 200-300 bucks + the billet caps them selves.
But the again, everything seems to be under risk. Even the crank and rod caps too!!
...
Im like you, I wont rev high and Im only looking for 500whp.
But if a cap goes on me after doing all this work on fresh engine build, that would be game over for me. Ill just move onto something else.

Yeah, it is a tough decision. If I didn't want to learn and build this engine myself, I would have paid someone else to do it. This is the first engine I've ever taken apart, and I wanted to do as much as possible. I've learned A LOT!

If I had paid someone else to so it, I probably would have spent the extra $1k to do the billet main caps ($550 for the caps, $150 for ARP main bolts, $200-300 for the machining, plus cost in bearings), maybe put on different cams and adjustable cam gears and had someone degree the cams for me (another $2500), maybe have added ARP rod bolts ($150 plus machining), maybe have spent another $400 over the cost of my new OEM harmonic dampener for an ATI, WPC treatment, etc. Plus another $5k for someone else to remove, teardown, assemble, and reinstall my engine.

It all adds up. Somewhere you have to draw the line or it becomes an endless money pit! I've made my decisions and will just have to live with them.... Don't stress it - it's just a car.

If this engine does eventually blow, I will probably salvage the engine parts to sell, convert it to electric to putt around town in, and build a Factory Five GTM for the track.

Dave

- - - Updated - - -

WPC is actually used in OEM applications by Honda, for certain on the Fit piston skirts. I think it comes down to a logistics issue with their various suppliers. There may also be some bean-counters involved.

I did not treat the saddles; the main guy at WPC said that the material is a PITA to get out of all the little crevices and holes in the cylinder heads.

Of course with the K-series the saddles are separate from the head...

Fit piston skirts !!! Love it.

I wonder if you could pack the whole head with Play Dough or some other putty easy to remove, and then treat the cam saddles?

Yeah, the K-series is a much nicer platform to work with. I think Ross was wise to do his k-swap.

 

[E-Nough Logic]

Ok, Just read it.
So, for what you explain its a hard decision.
Sounds like it would be good insurance to change them, The machine work sounds to be at around 200-300 bucks + the billet caps them selves.
But the again, everything seems to be under risk. Even the crank and rod caps too!!
...
Im like you, I wont rev high and Im only looking for 500whp.
But if a cap goes on me after doing all this work on fresh engine build, that would be game over for me. Ill just move onto something else.

Once align hone has been done the centerline of the crank will change and the oil pump clearances will need to be reworked as well. It can be done right, but it also opens up a whole new can of worms vs keeping stock. I thought the mains cracking was a major problem for stroked motors more so than stock crank motors? I'm sure Mac has done the research.

 

[Mac Attack]

E-Nough is right, I wanted to do as minimal machining as possible. I did confirm my main bore diameter (with a dial-bore indicator) and checked the main alignment (with a precision straight-edge and feeler gauges).


On the rod bearings... I waited over a week for different-sized OEM rod bearings for three of the rods. Well, that made one rod go to ~0.0019", but it wasn't enough to change the other two within spec. One's big and the other's too small, even with the smallest and largest bearings Honda makes.

I have no idea. There is basically no way to screw this up. Each rod cap is matched to the correct rod, and each piston is in the position I removed them from the engine (and pointed the correct way). The rods big ends weren't touched. The crank journals were just micropolished. Nothing should be different with just new replacement OEM bearings. The Honda bearings have a 0.0001" tolerance, but that is still not enough to account for the variance I'm seeing with the Plastigage.

The Plastigage shows uniform squish, and with the locked down crank and feeler gauges stuck in the sides, I'm sure it's an accurate reading. I even used my cheapy dial bore and micrometers to measure one of the rod clearances (empty big end ID, crank journal OD, then the OEM bearing thicknesses listed above), and the measured results were "close enough" to what the Plastigage was showing.

So, I'm ordering new ARP rod bolts and I'm trying to find a good local machinist to consult with. Since I'm going to need some work on the rods, I'm just going to have everything checked. I'd like to open up my piston-to-wall clearance a bit more from Wiseco's recommended 0.0030"... maybe to more like 0.0040". Then check the crank journals and maybe magnaflux the crank to be sure there's no problem with it. Ask about removing the OEM ball plugs from the crank so I can clean everything, and then Loctite threaded inserts back in.

I've waited 1.5 years. What's another 3-4 weeks to make sure everything is right? I still have a lot of old parts to clean in the meantime. And I can work on my intake manifold and fueling system.

Dave

 

[nsxnut]

So, I'm ordering new ARP rod bolts and I'm trying to find a good local machinist to consult with. Since I'm going to need some work on the rods, I'm just going to have everything checked. I'd like to open up my piston-to-wall clearance a bit more from Wiseco's recommended 0.0030"... maybe to more like 0.0040". Then check the crank journals and maybe magnaflux the crank to be sure there's no problem with it. Ask about removing the OEM ball plugs from the crank so I can clean everything, and then Loctite threaded inserts back in.

I've waited 1.5 years. What's another 3-4 weeks to make sure everything is right? I still have a lot of old parts to clean in the meantime. And I can work on my intake manifold and fueling system.

Dave

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