The machine shop I use which does top notch work, but must be lacking in these details, put 1mm OS In & Ex valves in. He did several Ford 2.3's & a Mk3 Supra in the past for me & just did a D16Z6 for me also. He's the main race shop around.
I said I wanted 1mm OS valves but everyone knows not to do both (due to V2V clearance). We went on a cruise & came back to this.
He also wanted me to try out his new porter so they did a full port & matched the IM. It's really a thing of beauty. He cut the seats to match the port so no going back.
Seems my only option is to stick with the stock cams.
I was really upset & left the head there for now. It's not assembled yet since he was waiting for my seals.
Just building a nice sreet motor - ITR pistons,RMF header, Rocket springs, 68mm TB, ITR type IM (no butterflies), polished crank.
At least with the Rocket springs it can rev higher & with these valves should flow lots of air.
Guess I'll go get it with just the #1 valves & locks & do a V2V clearance check through the entire cam gear degrees for clearance. Anyone have any experience with this?

 

Watch your overlap

 

Has anyone done this with the stock GSR cams?

 

This is not necessarily a bad thing it will work, you just have to be vigilant in your measurements. If he sunk the valves deep enough into the head there will be less issues with clearance but you will need to mind your valve spring install heights.

Best advise is to check clearance. I believe someone has measured Skunk2 Tuner1's with +1mm I/E valves, you will need to search.

 

The bad news..... I was under the impression that doing +1mm valves requires oversized valve seats.

 

I believe you are correct one needing oversized seats for +1mm valves.

OP, you will just be cam limited so make sure you measure your v2v clearances and you'll be fine.

 

Ok. Thanks. I'll get some super lite weight springs, lock the vtec & measure the clearance with the stock gsr cams. Doesn't look like he sunk them at all.

 

Yes that would be the way to go about it. Once you see how much room you have, you'll be able to have an idea of how big of a cam you can go. Most likely since its +1mm on both intake and exhaust valves, you'll be limited to a "stage 1" type of cam.

 

:-\ OS valves.

Really sucks if it wasn't sunk in, and why was OS valves put in anyway? Was the shop told to? I would think they would be redoing or getting a new head for this mistake..

I've had alot of customers, really do OS valves on the intake and leave the exh stock, this allows for decent v2v and opens up the camshaft options a bit.

I've v2v a OS valve setup with CTR cams, found .032 on settings +1 int / -1 exh, very little room, .030 is the minimal i recommend for v2v safety on a race setup, on a daily setup i'd actually go a bit more, .035-.040.

 

He has this new hotshot porter & convinced me to try him out. It was just before Christmas, I just got done with a 12hr all night shift & we were going on a cruise just after Christmas. I dropped off some parts for machining & he said "hey we should put 1mm OS valves in to really take advantage of the porting, porter agrees." Was in that haze - I said ok do it. Well, I didn't mean both, since nobody does that.
He still insists "all of the experts he talks to does it". His porter even says it's common. They both insist the exhaust just has to be retarded which will increase power anyway.
I told them them that cams with 8 or 10 degrees of separation are not really optimum. Anyway I have everything so will show them the small amount of clearance. They gave me the flow #s & it's 261 & 189 @ 28". I would have thought with the big valves it would be higher, since my cams will be limited.

 

http://jhengine.com/heads/bhheads/rsf3-honda-bdh-heads/
this is the top notch head work cnc does and they use os valves on both intake and exhaust. Just check your clearance to be sure.

 

DDtech - was that .032" at +1 in/ -1ex with 1mm in & ex valves? He said today they can sink them in a bit. How much can we sink them? Seems like the limit would be the adjuster & spring pressure since the stem would essentially be longer (above the seat) - reducing the spring pressure. I'm using the Rockets with 55'/lb.

 

If you didn't get mixed up and he actually told you to retard the exhaust cam chalk it up as a loss and walk away this guy doesn't know what he is doing.

 

It's not worth it to have them sink the valves, run it at the proper installed height.

 

You can sink the valves but like stated previously that will change your install height which will lower your seat pressure and that is a band aid on big problem. The purpose for getting cylinder head work is to increase the potential of your build not limit it. The only time we run oversized valves is on bigger bores where we can play with the chamber and increase lift flows acrross the board.We have seen heads with OS valves that customers bring in lose flow across the low lift numbers due to valve shrouding on a small chamber. Chalk it up to a lesson learned , you are unhappy with the results and the shop is trying to convince you that their mistake is ok and a normal procedure when in fact was a over sight ion their end. We have customers come in all the time heel bent on doing something that some one told them works and we have to be the ******** to refuse to do it and once we explain why their buddy with the dremel is wrong some get it some get pissed but its our job to educate based of our experience. If a limited head will work with your bottom end then use it if not then don't settle for bad work and lack of knowledge.

 

Thanks guys. It's just my dd ex coupe, so not a big issue, yes it's a big lesson, as is life. I'm just finishing it up because my son moved on back to his drifting 240's & didn't want it after I found a perfect stock ex from a coworker that he had to have, which I used the motor for my 76 cvcc, which is my main focus car wise. His friend then totaled his GSR, so much of that is going into the ex. Then back to my Performance Ported 11:1 D16z6 going in the 76.
Back to v2v & cams. I checked v2v with my stock cams. Not the complete range just cursory & there is lots of clearance - at +6 ex & -6 in there is .040. I was just trying worst case. At +10 ex & -10 in there would be contact. At 0-0 there is huge clearance. Granted this is w/ stock GSR cams. So now the quandary- looks like I would have room for at least ITR/CTR cams ( which I would check also before putting it all together.)
Thoughts?

 

Your numbers are not correct, are you checking clearances with vtec locked?

 

1.) You don't NEED oversized valveseats to go with oversized valves, however it puts the 45° sealing angle WAY out at the edge of the seat which doesnt always hold up real well long term. I prefer oversized seats if you want to do it right.

2.) Sinking the valve to get it to seal is a terrible practice. The whole point of oversized valves is increased airflow. What gains you see from the oversized valves will now be negated because the valve is sunk so far in the seat. Also makes the valvesprings produce less tension unless they are shimmed to compensate. Without shims this can lead to valve float which leads to engine damage.

3.) +1mm oversized on both sides is fine on stock cams and even mild cams like the Skunk2 Tuner Series. The only time it becomes a problem is will the aggressive cams like the Skunk2 Pro or equivalent.

4.) Valve to valve clearance must be checked with vtec engaged.

5.) Beer

 

Yea it does not seem you hav vtech locked you should not be seein those clearances with that setup .. Make sure your lock the rockers and re measure

 

I second the beer notation

 

Yes locked tight. I switched the pins & put a small rubber grommet under the one pin to ensure all 3 are locked together (so it pushes in on the spring loaded pin). Locked tighter than a frog's butt. It/they are riding on the vtec lobe. I set the valve clearance to 0. Belt is tight & clamped with vice grips. It is however the stock GSR low lift, low over lap cam also, so not sure who has ever checked that- one of you probably have. Maybe the valves are sunk a bit. But like Soaringchimp says, with the stock cam the clearances are fine - which is what I'm seeing. Looks like I need to check the valve stem height - the plot thickens.

 

Haha "the plot thickens" yeah check your install height . Really curious to see the valve job not for nothing but if they did a not so hot valve job then maybe your concerns are just a valve change away. If you are not satisfied with where your seat pressure falls after install height you can always install new seats and just have them eat the cost to repair their mistake.

 

Well the top of the retainer with these soft springs is @34.5mm. So that sounds about right from what I've read. Well not sure why but everything seems ok. So I'll just get some Skunk2 Tuner2's & be happy.

 

What retainer are you using(don't remember if you already specified) and where does your 45 degree cut sit on the face of your valve and seat?

 

Stock retainer, new locks, Rocket 55 springs. I don't completely understand about the 45 deg angle but it's not at the extreme edge.