Valvetrain components = OEM or "upgrade"

L_RAO

L_RAO

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Pasadena, CA
Wanted to get some opinions/experiences on those who have gone through their valvetrains. In my case, if I go aftermarket, I will be going with Manley components.

1. Valve guide = OEM or aftermarket?
2. Retainer = OEM or aftermarket (if aftermarket, I am going to stay with stainless)
3. Valve spring = does anyone what the OEM springs are rated to/at?
4. LMA = I think I'll go ahead and upgrade to the newer spring style.
5. Cotter valve = that is what most manufacturers refer to as a "lock", right? OEM or aftermarket?

I have already decided on a 35.5 mm intake valve from Manley. The rest is still up for debate.
 
I'm not pursuing the nth N/A performance for my engine build, so here's my $0.02 on a RELIABLE OEMish setup for ~500 boosted WHP. Most of my thought process begins here in my build thread:
http://www.nsxprime.com/forum/showthread.php?t=154927&page=9

Of course, everyone has different goals and how much money available to spend, so here goes my approach....


L_RAO said:
1. Valve guide = OEM or aftermarket?
Click to expand...
With ~130k hard daily-driven 8k redline shifts on my engine (that's the benefit of a quiet OEM exhaust btw), my valve guides were in perfect shape. I had new OEM ones purchased to change out, but have decided not to. My engine builder was amazed. Valve seats are perfect too. Why mess with those if there's no wear as opposed to something that's fatigued like keepers or retainers or springs as discussed below?

Maybe I don't know the benefits of aftermarket valve guides? Is there some super-slippery non-wearing material out there that's cheap too? :smile:


L_RAO said:
2. Retainer = OEM or aftermarket (if aftermarket, I am going to stay with stainless)
Click to expand...

This is related to your spring question below, but if you go with custom springs, you'll probably have to use their retainers too. In my Ti retainer search, there's various Ti alloys and heat-treating processes that make some a lot better than others. But of course, that's $$ too.

So, for my setup, I bought new OEM retainers to use with my new OEM springs. I also bought new OEM spring seats too, even though they're not "stressed" or wear. They were cheap....

I talked with Eibach about custom springs with lower spring rates than what they offer in their catalogue (since those rates are insanely high). Also talked with Comp Cams and Supertech....


L_RAO said:
3. Valve spring = does anyone what the OEM springs are rated to/at?
Click to expand...

I haven't measured the OEM spring rate. The SM gives service limit height though. Since I'm not going for insane power, or big cams, I didn't want an increased spring rate for my rebuild.

However, due to 20 years of heat cycling, 130k miles, and the fact I want ~10psig boost, I bought new OEM springs. Had to wait on those from Japan :smile:

I'll ask my machinist to measure the old and new spring rates if the new springs haven't already been installed in the heads. I've never seen those numbers published on here either.

EDIT - I estimate seat pressure at ~56lbs from here:
http://www.nsxprime.com/forum/showpost.php?p=1543107&postcount=228

Eibachs are 80lbs seat pressure.

Alright, bored at work so I calculated Supertech and Eibach spring rates...

Supertech:
[email protected] seated
220lbs@12mm open
Rate = (220-67)/(36.4-12) = 6.2lbs/mm = 157.5lb/in

Eibach:
[email protected] seated
[email protected] open
Rate = (226-80)/(36.4-23.4) = 11.23lbs/mm = 285.2lb/in


L_RAO said:
4. LMA = I think I'll go ahead and upgrade to the newer spring style.
Click to expand...

Yes, I bought the SOS kit about a year ago for my build. I would see how much they cost straight from Honda for the part numbers greenberet posted though.


L_RAO said:
5. Cotter valve = that is what most manufacturers refer to as a "lock", right? OEM or aftermarket?
Click to expand...

I know of them as valve "locks" or "keepers." Yes, these are stressed too and can break. You'll get these from your valve and retainer people since they might have their own proprietary design and what angle they think is best....

I kept my OEM valves since they were in perfect condition. Just decarboned, polished and they were as good as new. Good enough for me and the $$ involved for aftermarket ones. So, I bought new OEM keepers.



I'm impressed with Honda's design and their mix of performance, longevity, and cost. Their engineers really are pretty sharp so I didn't want to deviate much from that :wink: Not saying it can't be improved, but I trust OEM Honda over aftermarket when trying to avoid dropped valves for another 20 years and 150k miles!!!


New OEM springs, retainers, keepers, and seats:

springs_locks_retainers_seats.JPG
 
Last edited:
Mac Attack said:
I'm not pursuing the nth N/A performance for my engine build, so here's my $0.02 on a RELIABLE OEMish setup for ~500 boosted WHP. Most of my thought process begins here in my build thread:
http://www.nsxprime.com/forum/showthread.php?t=154927&page=9

Of course, everyone has different goals and how much money available to spend, so here goes my approach....



With ~130k hard daily-driven 8k redline shifts on my engine (that's the benefit of a quiet OEM exhaust btw), my valve guides were in perfect shape. I had new OEM ones purchased to change out, but have decided not to. My engine builder was amazed. Valve seats are perfect too. Why mess with those if there's no wear as opposed to something that's fatigued like keepers or retainers or springs as discussed below?

Maybe I don't know the benefits of aftermarket valve guides? Is there some super-slippery non-wearing material out there that's cheap too? :smile:
Click to expand...

Yes, I am on the same page as you - an OEMish high performance build. No, there is no performance benefit to an aftermarket valve, except for maybe a weigh reduction. If I wanted a "performance" coating/finish, I would go with the WPC-treatment on the stem. Swain Tech says their friction-reducing coating for valve stems is only useful on NASCAR spec engines.



This is related to your spring question below, but if you go with custom springs, you'll probably have to use their retainers too. In my Ti retainer search, there's various Ti alloys and heat-treating processes that make some a lot better than others. But of course, that's $$ too.

So, for my setup, I bought new OEM retainers to use with my new OEM springs. I also bought new OEM spring seats too, even though they're not "stressed" or wear. They were cheap....

I talked with Eibach about custom springs with lower spring rates than what they offer in their catalogue (since those rates are insanely high). Also talked with Comp Cams and Supertech....
Click to expand...

I will probably stick with the OEM spring/retainer combo this time around, as custom camshafts (necessitating new springs) probably won't happen for a while (unless I hit the lotto).

I haven't measured the OEM spring rate. The SM gives service limit height though. Since I'm not going for insane power, or big cams, I didn't want an increased spring rate for my rebuild.

However, due to 20 years of heat cycling, 130k miles, and the fact I want ~10psig boost, I bought new OEM springs. Had to wait on those from Japan :smile:

I'll ask my machinist to measure the old and new spring rates if the new springs haven't already been installed in the heads. I've never seen those numbers published on here either.

EDIT - I estimate seat pressure at ~56lbs from here:
http://www.nsxprime.com/forum/showpost.php?p=1543107&postcount=228

Eibachs are 80lbs seat pressure.

Alright, bored at work so I calculated Supertech and Eibach spring rates...

Supertech:
[email protected] seated
220lbs@12mm open
Rate = (220-67)/(36.4-12) = 6.2lbs/mm = 157.5lb/in

Eibach:
[email protected] seated
[email protected] open
Rate = (226-80)/(36.4-23.4) = 11.23lbs/mm = 285.2lb/in




Yes, I bought the SOS kit about a year ago for my build. I would see how much they cost straight from Honda for the part numbers greenberet posted though.
Click to expand...

oemacuraparts.com has them for $24.82 a piece.

I know of them as valve "locks" or "keepers." Yes, these are stressed too and can break. You'll get these from your valve and retainer people since they might have their own proprietary design and what angle they think is best....

I kept my OEM valves since they were in perfect condition. Just decarboned, polished and they were as good as new. Good enough for me and the $$ involved for aftermarket ones. So, I bought new OEM keepers.
Click to expand...
Hmmm...not sure what the Manley 35.5 mm valves are going to cost me, but oemacuraparts.com has the 36 mm intake valve (from 3.2L engines) for $20.76/valve, vs. $29.51 for the 35 mm intake valve. The 36 mm OEM valve might be cheaper than the Manley 35.5, but it might cost me a bit more in machining costs. We'll see.


I'm impressed with Honda's design and their mix of performance, longevity, and cost. Their engineers really are pretty sharp so I didn't want to deviate much from that :wink: Not saying it can't be improved, but I trust OEM Honda over aftermarket when trying to avoid dropped valves for another 20 years and 150k miles!!!


New OEM springs, retainers, keepers, and seats:

springs_locks_retainers_seats.JPG
Click to expand...

Good stuff. Thanks for the input.
 
Last edited:
The OEM parts are much better than most aftermarket parts, that is for sure on this one.
 
I would never put Ti retainers in a car whose motor doesn't get rebuilt often.

Last time I was at Buttonwillow, my friend's Ti retainer cracked and dropped a valve in his Integra Type R. Was a sad day.
 
This may seem a bit off topic but since we're talking about valve-train stuff here, is it possible to pull the heads with the engine still in the car?
 
I will update everyone as soon I drop everything off at the head porters.

My research tells me that Ti retainers are not a good idea, so I'm going to go with stainless - the question really becomes OEM or Manley.

I think Manley offers a hollow stem valve, but the OEM Honda valves are pretty light to begin with. I'll post up weight and price differences when I get them. I have no need for titanium valves.
 
When I did my engine build I did research on the Manley valves (and pistons) and wasn't impressed when compared to the likes of Ferrea valves.

Ferrea should have my valve dimensions on record since I sent them a intake and exhaust valve.

They can make hollow stem and hollow stem with sodium filled valves that you see in the Z06.

Did you consider Ferrea?
 
BATMANs - Did you go with hollow stem or undercutting on yours?

Curious on the cost differences between OEM ~$25-30 a valve vs aftermarket ones like Ferrea. Ferrea stuff is very nice.
 
Yes, I did consider Ferrea. My builder does not like them because a lot of their stuff is actually made in Argentina. Everything from Manley is made in the USA.

Not sure if I personally can tell the difference between something made in Argentina vs. the USA, but given his track record of engines built, I'll take his word.

I have not heard anything bad about Manley, other than not a lot of (import) people use them, but that could be a function of profit margin (i.e., it is more profitable for a shop to sell Supertech/Ferrea than it is to sell Manley). The big HP domestic guys LOVE Manley.

UPDATE: Got off the phone with Manley, and they did not recommend the Ti retainers for a "street" car (i.e., if you didn't tear apart the engine every year/race season).



BATMANs said:
When I did my engine build I did research on the Manley valves (and pistons) and wasn't impressed when compared to the likes of Ferrea valves.

Ferrea should have my valve dimensions on record since I sent them a intake and exhaust valve.

They can make hollow stem and hollow stem with sodium filled valves that you see in the Z06.

Did you consider Ferrea?
Click to expand...
 
Mac Attack said:
BATMANs - Did you go with hollow stem or undercutting on yours?

Curious on the cost differences between OEM ~$25-30 a valve vs aftermarket ones like Ferrea. Ferrea stuff is very nice.
Click to expand...

The 35 mm intake valves (OEM on 3.0L engines) are $29.51 each from oemacuraparts.com, they weigh 54.7 grams each (per BATMANs).
The 36 mm intake valves (OEM on 3.2L engines) are $20.76 each from oemacuraparts.com
The 30 mm exhaust valves (OEM on 3.0L & 3.2L engines) are $43.69 each from oemacuraparts.com, they weigh 47.8 grams each (per BATMANs).

The Manley intake valves (35, 35.5 or 36 mm) are $28.50 each.
 
Last edited:
Mac Attack said:
BATMANs - Did you go with hollow stem or undercutting on yours?

Curious on the cost differences between OEM ~$25-30 a valve vs aftermarket ones like Ferrea. Ferrea stuff is very nice.
Click to expand...

I bought mines from here. I think it was for $500 shipped on my best offer. I really dun remember though. It was solid stem since they are still lighter than the OEM. They are all undercut. Ferrea is the only one that I found that didn't actually cut away material in the undercut process. They just did a squeeze forge which also preserved the grain.

L_RAO said:
Yes, I did consider Ferrea. My builder does not like them because a lot of their stuff is actually made in Argentina. Everything from Manley is made in the USA.

Not sure if I personally can tell the difference between something made in Argentina vs. the USA, but given his track record of engines built, I'll take his word.

I have not heard anything bad about Manley, other than not a lot of (import) people use them, but that could be a function of profit margin (i.e., it is more profitable for a shop to sell Supertech/Ferrea than it is to sell Manley). The big HP domestic guys LOVE Manley.
Click to expand...

I'm not sure if made in Argentina is a good or bad thing.

However considering that my machine shop called Florida, spoke to a live person that received an intake and exhaust valve sample from my NSX and was able to turn it around in less than a week (we were told that they had to make the valves since the NSX valves are not off the self - at least the specs that we wanted), I can't help but to wonder if the valve was even made in Argentina since it would take longer (if they want to make a profit) to ship just a set of NSX valves.

From my research the 1000rwhp+ big single turbo MKIV folks used them (which is what got my attention when I was looking for valves). There are stories abound that Ferrea valves are known to bend if you were to over rev them from mis-shifting or some other event where the valve and piston were to touch at high RPMs. Other brands like Manley I've heard stories that the heads would break off which is worse since not only is the piston damaged, but the cylinder wall and head face will be pulverized. If ur luck that's it. If not the head can punch a hole into the wall.

I suspect that the Ferrea valves alloy and forging process has much to do with it not breaking off.I think the Ferrea are hard on the outside and soft on the inside. It's a similar format to a Samurai katana, for example where the blade is hard but the spine is soft so that the sword won't snap in two.

Manley made in Inda and South America?!?!?

http://speedtalk.com/forum/viewtopic.php?f=1&t=28778

"Dave took the words out of my mouth. He actually gave us a Ferrea valve that came out of one of the Bullish Solara's where all 6 pistons exited the block and the Ferrea valve simply bent. All that was needed to fix the EXPENSIVE head was a new set of bronze guides and a couple valves. We use this bent valve as a selling device for when people are asking this same question."
 
Last edited:
L_RAO said:
The 35 mm intake valves (OEM on 3.0L engines) are $29.51 each from oemacuraparts.com, they weigh 54.7 grams each (per BATMANs).
The 36 mm intake valves (OEM on 3.2L engines) are $20.76 each from oemacuraparts.com
The 30 mm exhaust valves (OEM on 3.0L & 3.2L engines) are $43.69 each from oemacuraparts.com, they weigh 47.8 grams each (per BATMANs).

The Manley intake valves (35, 35.5 or 36 mm) are $28.50 each.
Click to expand...

I was paying closer to $20 each Ferrea valve.

http://www.ebay.com/itm/Ferrea-for-...Parts_Accessories&hash=item51a13e8a6b&vxp=mtr
 
So I've done some more researching, and I'm trying to sift through all the "information" that's out there on the internet.

Titanium valves offer a superior combination of strength/weight vs. stainless. However, they are expensive (we'll disregard that for now) and supposedly don't last very long, in part due to the copper/beryllium valve seat required.

However, I read that GM uses a titanium valve for its LS7 engine, which is designed to last 100,000 miles. I'm wondering what technology and/or material advancements they are utilizing in order to make the use of a "race" valve material in a street car.
 
USAFguy22 said:
This may seem a bit off topic but since we're talking about valve-train stuff here, is it possible to pull the heads with the engine still in the car?
Click to expand...

I think it could be done, but you would need some serious back muscles & strength. Those heads do not come off the dowels easily & there's not enough places to pry without damaging the head surface. It's a struggle even on the engine stand. (Just pulled my heads off this weekend)
In my mind it's easier to drop the engine then you can see everything & get to everything.
 
If you have removed NSX heads you will know you cannot remove them in the car.

(unless you mean to remove the engine, remove the seats and put the motor in the passenger compartment, then remove the heads - this would be "in the car" - LOL)
 
angus said:
If you have removed NSX heads you will know you cannot remove them in the car.

(unless you mean to remove the engine, remove the seats and put the motor in the passenger compartment, then remove the heads - this would be "in the car" - LOL)
Click to expand...

Haha thanks ;)
 

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