high idle speed issue

[madkaw]

40 minutes ago, Jeff Berk said:

Would using the turbo Z pump be strong enough to pump oil through both the internal oiler and spray arms? Is there a way to check how well it's working?

I would NOT recommend running both . Just stick with a internally oiled cam . It’s hard for the system to put out enough volume for both . I think the cam spray bar is ineffective when using both . The oil barely reaches the lash pads - at least the tests I did. Maybe with my Kameari pump it might work .

Simple test is to drop out your drive spindle on the dizzy and drop in a drill with something to drive the pump . Get your mechanical oil pressure gauge hooked up where you can see it . Fire up your drill and watch your pressure and your oil flow . I made a valve cover with a cut off top to watch without oil getting everywhere .

Ive done this test using the modified valve cover while the motor was running . 

I wouldn’t , and haven’t started a motor without performing this test . I’ve have never lost a cam yet . I’ve had a Schneider , ISKY , and now a Bonk cam . 
And I use Rotella truck oil - nothing fancy

 

[madkaw]

4 hours ago, Zed Head said:

Sometimes they flatten a lobe even if everything is done right.  @madkaw knows, if I remember right.

Who is the camshaft shop that he uses?  

I’ve never lost a cam - but heard many stories 

[Zed Head]

Who was that then?  They're out there somewhere....

Here's one but it's not the one I was thinking of.  I think it was on Hybridz.

 

Edited July 20, 2020 by Zed Head

[madkaw]

Wasn’t me . I made a thread here many years ago about this subject of dual oiling systems  , but I think it’s lost . 
There’s been man stories of lost cams . With all the variables , it’s hard to attribute a wiper lobe to one thing .

Spray bars -to me - are problems just waiting to happen 

[Jeff G 78]

18 hours ago, siteunseen said:

@Jeff G 78

I think he runs both on his race car? I have not built mine yet but I will use both on my e31 head with a Schneider cam kit. I have turbo pumps on both my Zs and they flood the valvetrain when I spun the pump with a drill before 1st start up. I read a lot of post with people using both with the higher volume pump. Actuall my 9/76 has both on the early n47 head from Nissan. That came looked great in 2011 when I bought the car. That's from '76 to 2011 without the turbo pump. At idle it barely moved the needle on the gauge. With a turbo Melling pump it sits halfway then I installed a new head with just internal oiling cam. Now it's 3/4 gauge at idle. My spray bar 240 with the turbo pump pegs the needle at idle. 

the melling 152 is the turbo pump. Cost me $60 8 years ago from Advance Auto.

 

 

I run only internally oiled on my P79 race car head.  I ran both for a while on one of my motors, but eventually blocked off the tower ports and went with only internally oiled.

[Jeff Berk]

It's been a year and I just completed a valve lash adjustment. It looks like the mechanic did not reinstall the spray bars and only went with the internally oiled cam shaft. One issue I notices was that there was a little damage to the cam on cylinder 5. I'm assuming that since the chip is off to the side, it will not impact anything. 

[siteunseen]

Damn mechanics! What's the rocker pad look like?

[Jeff G 78]

I'd be a bit worried about that chip as it's a few mm into the wipe pattern.  Make sure there are no protrusions around the edges that could eat the rocker.  I'd also be a bit worried that it could propagate across the lobe.  

[Zed Head]

On 7/19/2020 at 9:04 AM, Jeff Berk said:

Well I'm back to where I was last year. I got this message from my mechanic when I brought the car back in to have the valves adjusted:

Jeff, For some reason your cam/head has an oiling problem. The same cam lobes that were destroyed on the first cam are bad on the new cam. I have a new cam and rocker arm set coming next week. This cam uses a different oiling system than the original cam.

Followed by:

The new cam will be internally oiled. You can use both the spray bar and internal oiling, the oil pump does not have the volume to do both. I think we should also replace the oil pump with a turboZ oil pump. I have not got the complete cost of the replacement parts yet. I will keep you posted.

Any opinions on this? The mechanic specializes in Japan and British car restoration and races a 510 so he seems to know what he is doing. 

I don't see any holes in the three cam lobes you showed.  The internally oiled cams have those to let the oil out.

Why does he say "new cam" when it looks like you got a used one?  That chip might work but it could also self-destruct rapidly.  Looks like the chip is on the base circle though, where there should be almost no pressure.  Only the anti-rattle springs pressing on it.

[Jeff G 78]

4 minutes ago, Zed Head said:

I don't see any holes in the three cam lobes you showed.  The internally oiled cams have those to let the oil out.

Why does he say "new cam" when it looks like you got a used one?  That chip might work but it could also self-destruct rapidly.  Looks like the chip is on the base circle though, where there should be almost no pressure.  Only the anti-rattle springs pressing on it.

You are right!  I wasn't even looking for the oil holes.  That's an externally oiled cam and I can't tell if it's new, but there is a wipe pattern that wouldn't be there if it was brand new.

[Jeff Berk]

I just sealed the valve cover back up so I can't check if it is contacting the wiper.

Yes, there are spray holes, they just don't show up due to the position of the lobes. 

Yes, it was a new cam shaft (last year).

The mechanic has been non-responsive lately as he's working as a crew on a Miata racing team and doesn't have much time for his shop.

I think I'm going to treat this as a mole on my skin. I'll just keep an eye on it and check to see if there are changes.

[Jeff G 78]

I just looked at the pics of my internally oiled cam and the oil hole is opposite the lobe peak on the base circle.  Zed Head thought that the chip was on the base circle, but I don't think that's the case.  If true, there would be an oil hole visible.  I believe the chip is at the peak of the lobe and it's just hard to see due to the camera angle.  If that's the case, the chip is on the peak of the lobe, not the base circle, though the majority of the chip as on the downslope.  Still, the loads will be high in that section of the lobe.