Nova_Dust

Hi all, I am currently purchasing parts for my build. Got most of them and now debating on what brand to purchase for valvetrain.

A quick run down on parts list:

RC 370cc
ITR fuel pump
RS machines 68mm TB
Blox IM
P8R head (P&P + 3 angle valve work)
Crower 405 cams + adjustable cam gears
OEM B20 headgasket

RS machines 84.5mm piston
stock rods
ARP head stud + rod bolts
ACL bearing (non race)
OEM water pump + timing belt

I haven't purchased a FPR.

I have been doing some research and reading regarding valve springs pressure at open and read it somewhere that it is best to stay under 200lbs. Too stiff of a spring will cause extensive wear on valvetrain components and cams; too soft will cause lost of power and potential valve float.

Crower: open pressure @ 0.908 = 153lbs, seat pressure @ 1.32 = 66lbs (coil bind = 0.710) [Crower website has open and seat reversed, I think?)

Brian Crower: open pressure @ 0.95 = 148lbs, seat pressure @ 1.4 = 48lbs (coil bind = 0.710)

Isky Street: open pressure @ 0.95 = 160lbs, seat pressure @ 1.4 = 54lbs (coil bind = 0.720) [max lift 480]

Isky Race: open pressure @ 0.95 = 204lbs, seat pressure @ 1.4 = 70lbs (coil bind = 0.720) [max lift 500]

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Crower 405 gross lift w/1.75 @ 478/469
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Some people also say stick with the same brand.

I usually purchase all parts before I send the car out for work, that way, I know what I am using, how much I am saving, and most importantly, learn a thing or two. The car is a daily driver with summer road racing for sometime now. Idel will be rough as some pointed out but that is not my concern. If it become unbearable, I have other means of getting to work.

The number tells me to go with Isky Race, at least that's what I think.

Thoughts? Thank you guys.

Nova_Dust

I did a quick ratio calculation to get Crower open/seat pressure from 0.908 to 0.95, and 1.32 to 1.4 and the numbers are 160lbs/62lbs. If that helps.

b19coupe

JG and Supertech also offer valve train components for the LS/B20. I am in the process of putting together a similar build, with the 405's, so I will be following your progress with interest. Sorry, but I really don't have any useful information to offer-talk to Tom at Portflow tough-he is a goldmine of information.

Nova_Dust

Thanks b19coupe, I will try to find some specs on their valvetrains.

Nova_Dust

BTW, am I right to say that no one makes oversize valves for nonVTEC heads? 33/28 is the biggest we can go?

b19coupe

Stock non-VTEC intake valves are 31mm, exhaust valves are 28mm. Supertech offers 31.5mm intake valves. My head porter is putting 33mm intake valves in an LS head for me, but I do not know where he sourced them.
Supertech has the specs on their valve springs on their site under 'inventory'-'racing valves'.
http://www.supertechperformance.com/

Nova_Dust

Can't install Flash at work, damn I will view Supertech's webpage at home.

I E-mailed JG, not sure if they would disclose any spec, but worth the try.

I am using a P8R head, so 33mm intake valve. Maybe that's what your head porter got them from.

Non-VTEC guys just gonna have to work with what we have

bambam

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Nova_Dust &raquo;</TD></TR><TR><TD CLASS="quote">Can't install Flash at work, damn I will view Supertech's webpage at home.

I E-mailed JG, not sure if they would disclose any spec, but worth the try.

I am using a P8R head, so 33mm intake valve. Maybe that's what your head porter got them from.

Non-VTEC guys just gonna have to work with what we have </TD></TR></TABLE>

33mm is plenty. People make 280 whp on stock Dohc vtec 33mm valves, so I don't foresee that being your weak point. The problem is with the head assembly. The non-vtec rocker is functionally not meant to handle the high RPM's. Not to mention, the 405's are still Dwarf sized cams compared to some of the biggest vtec cams. We all know the power is in the head.

Good luck though. BTW, you'd be better off fitting the P8R valves into an LS head because of the smaller combustion chambers. You want to make up as little of your compression as possible from the dome of the piston.

non-VTEC

SI valves and Ferrea offer valve blanks in diffrent sizes that you might be able to "make work" if your machinist is good enough.

should be an instersting build up and make some good non-vtec power

Rocket

I would get the valvetrain kit that addresses the issue of the exhaust spring installed hieght is taller than the intake spring installed height. There are three approaches to this

1. Make a longer spring for the exhaust side
2. Make a thicker spring seat for the exhaust side enabling the use of the same spring on either intake or exhaust
3. Screw it and do nada. Just a lil detail that is only ~0.050" difference in installed height.

Nova_Dust

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Don Lackey &raquo;</TD></TR><TR><TD CLASS="quote">I would get the valvetrain kit that addresses the issue of the exhaust spring installed hieght is taller than the intake spring installed height. There are three approaches to this

1. Make a longer spring for the exhaust side
2. Make a thicker spring seat for the exhaust side enabling the use of the same spring on either intake or exhaust
3. Screw it and do nada. Just a lil detail that is only ~0.050" difference in installed height.</TD></TR></TABLE>

So you are saying install the aftermarket springs to OEM spec? Factory installed heights are intake @1.320" and exhaust @1.425". Brian Crower, for instance, suggests to install his springs at 1.400" on both intake and exhaust.

Is there a reason with the same height approach? Why is exhaust side higher than intake? Does it have to do with amount of exhaust volumn leaving the chamber?

Rocket

Depending on the free length of the sprnigs you could have less or more seat pressure than you want. The easy way is to have thicker spring seats on the exhaust side.

Nova_Dust

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Don Lackey &raquo;</TD></TR><TR><TD CLASS="quote">Depending on the free length of the sprnigs you could have less or more seat pressure than you want. The easy way is to have thicker spring seats on the exhaust side.</TD></TR></TABLE>

Thicker spring seat, I will look into that as well, thanks.

b19coupe

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Nova_Dust &raquo;</TD></TR><TR><TD CLASS="quote">I am using a P8R head, so 33mm intake valve. </TD></TR></TABLE>
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bambam &raquo;</TD></TR><TR><TD CLASS="quote">BTW, you'd be better off fitting the P8R valves into an LS head because of the smaller combustion chambers. </TD></TR></TABLE>
Two things that I did not know. Where is this information available so that I can educate myself?

Nova_Dust

I know it sounds silly, but I have always heard that P8R has 33mm intake valve.

I have the head at home, will measure the valves tonight.

Btw, a local engine builder suggested me to use Crower matching valvetrains. Isky seems to be a little on the high side (pound wise) and could induce potential premature cam wear, and whatnot.

I don't know, but you would think that Crower would use a different spec valvetrains for the 405, consider they suggest the same kit for 402T, 403 and 404; while 405 has a higher lift.

:shrugs:

Nova_Dust

Another questions, since there is no aftermarket valves for a P8R head (except exhaust valves, 28mm or 28.5mm), how would the stock valves hold up against large cams?

bambam

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Nova_Dust &raquo;</TD></TR><TR><TD CLASS="quote">Another questions, since there is no aftermarket valves for a P8R head (except exhaust valves, 28mm or 28.5mm), how would the stock valves hold up against large cams? </TD></TR></TABLE>

It's not the valves i'd be worried about. There's nothing wrong with stock valves. It's the non-vtec rocker assy i'd **** my pants over at 8k plus revs.

bambam

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b19coupe &raquo;</TD></TR><TR><TD CLASS="quote">Two things that I did not know. Where is this information available so that I can educate myself?</TD></TR></TABLE>
https://honda-tech.com/zerothread?id=1467903

There ya go.

https://honda-tech.com/zerothread?id=1292278

And pics there ^.

d16dcoe45

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bambam &raquo;</TD></TR><TR><TD CLASS="quote">

It's not the valves i'd be worried about. There's nothing wrong with stock valves. It's the non-vtec rocker assy i'd **** my pants over at 8k plus revs.</TD></TR></TABLE>I used to be worried about that as well. The ZC has the same style valve train. I was able to remove a rocker with my bare fingers on an LS head with every thing tightened down and the cams installed. The problem is the LS valvetrain is not shaft mounted like the dohc vtecs or even the sohc BUT it seems to be more of a "theoretical" problem, on paper its not the best design for high rpm running but in talking to some people who have experience running these LS motors to 8500 + it seems to be a non-issue.

Nova_Dust

Ya, over the weekend I helped a guy with B20 swap. Someone performed a valve adjustment and you can move around the screws even after you tighten down the rocker.

b19coupe

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bambam &raquo;</TD></TR><TR><TD CLASS="quote">There ya go.</TD></TR></TABLE>
Yes, but where did you get your information? A Honda technical paper? The internet? A burning bush?

Nova_Dust

P8R head only came with the S-MX wagon's B20B engine.

S-MX 96.11 to 2000
Chassis code: RH1, RH2
Engine: B20B
HOP Parts number: 17220-P8R-000
HAMP Synergy Parts number: H1722-P8R-010

Consider the amounts of B20 engines produced for CRV, Stepwagon, Orthia, and then S-MX wagons, you can see that P8R head is quite rare.

Perhaps it is a VTEC head, with a different stamp and slight variation?

bambam

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b19coupe &raquo;</TD></TR><TR><TD CLASS="quote">Yes, but where did you get your information? A Honda technical paper? The internet? A burning bush? </TD></TR></TABLE>

Japanese honda websites which I translated. No, seriously.
The only thing I can't figure out for the life of me is how the 9.2. compression ratio is possible with the larger combustion chambers. My math has it around 8.4:1ish. But, honda lists it as 9.2 so i dunno.

Stinkycheezmonky

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bambam &raquo;</TD></TR><TR><TD CLASS="quote">Japanese honda websites which I translated. No, seriously.
The only thing I can't figure out for the life of me is how the 9.2. compression ratio is possible with the larger combustion chambers. My math has it around 8.4:1ish. But, honda lists it as 9.2 so i dunno.</TD></TR></TABLE>

I'm assuming you're doing your math with the PHK pistons, right? Other than that, (this wouldn't be responsible for a 0.8 point CR jump) I HEARD awhile ago that the B20Z used a two-layer headgasket.

This brings up another point. Nova_Dust, are you sure the P8R head was available only on the S-MX B20B? What about all the B20Zs out there that have it? Not saying that makes it less rare, just trying to keep all the information straight, as I know it's difficult to find hard information on this thing.

&lt;--- P8R user

Edit: bambam, just read through your FAQ, very informative and well done. For the CR thing again, I don't know ANY of the theory/reasoning behind this, but could it have something to do with either 1.) the shape of the combustion chamber, even if it has a larger diameter, or 2.) whatever the hell is responsible for an increase in bore upping the compression (OS pistons in a rebuild would be the best example of that I guess).

Nova_Dust

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Stinkycheezmonky &raquo;</TD></TR><TR><TD CLASS="quote">

I'm assuming you're doing your math with the PHK pistons, right? Other than that, (this wouldn't be responsible for a 0.8 point CR jump) I HEARD awhile ago that the B20Z used a two-layer headgasket.

This brings up another point. Nova_Dust, are you sure the P8R head was available only on the S-MX B20B? What about all the B20Zs out there that have it? Not saying that makes it less rare, just trying to keep all the information straight, as I know it's difficult to find hard information on this thing.

&lt;--- P8R user

Edit: bambam, just read through your FAQ, very informative and well done. For the CR thing again, I don't know ANY of the theory/reasoning behind this, but could it have something to do with either 1.) the shape of the combustion chamber, even if it has a larger diameter, or 2.) whatever the hell is responsible for an increase in bore upping the compression (OS pistons in a rebuild would be the best example of that I guess).</TD></TR></TABLE>

On the Honda Japan website, only SMX utilizes P8R as part of the parts numbering system. I am basing my conclusion on that. Also, a friend of a friend who got a shipment of B20B all with P8R head (5 of them) and they all came from SMX.

Do you know where your P8R head came from? Did you get a P8R long block or you got the head later?

Thanks