Rocker Geometry Woes

[EuroDat]

What ever the reason for the difference in rocker arms, Datsun factory or dpllc, the wear patterns are just damn scary way out on the side like that. Lucky you caught it before it done too much damage.

 

Disappointing that this happened to start with. Goodluck getting it back together. 

Chas

[rossiz]

wow... i hadn't even noticed that. 

i believe multi-cavity molds are formed from the same cores, used repetitively. the cores are often castings themselves, taken from a single original, then treed up in groups depending on how many they will cast in a single pour. so the parts should be very close to identical in geometry. surface finish would vary, depending on the process used, but the shape of the "foot" would certainly not...

 

i will be calling dpllc today and hoping for some answers. i paid $590 (not including my own remedial "machining services") and a new set of lash pads will be ~$100 + a set of rockers at ~$250, so i'm not gonna take this lightly.

[S30Driver]

What a terrible situation with that reconditioned head.

Good that you caught it early though, before major damage.

 

Best of luck getting it all sorted out.

[rossiz]

@ 71Nissan240Z - just pm'd you regarding your rockers...

[Zed Head]

I'm not saying that those rocker arms are bad.  Just that they appear to be pulled from a collection of odd rockers.  I'm pretty sure also, that I can see the typical shiny line in the middle of the contact pad that used rockers get.  DPLLC probably just shipped a batch of collected rocker arms off to Delta for refinishing and pulls from the collection when a head is "rebuilt".  He just messed up on lash pad selection.

[Darrel]

never use datsunpartsllc or whatever his name of the month is for mechanicals. buyer beware.

[rossiz]

ok, so i called Al today at dpllc and calmly described the situation, including the stripped holes, the oil consumption and the rocker geometry issue. to his credit, he didn't get defensive or try to argue - he was apologetic and fair, said that if i shipped it back to him he would strip it down and do a complete re-build from scratch with another set of rockers, new seals and throw in a new head gasket. while i'm still on the hook for the tear-down and re-install, i'm ok with it as long as the head is done right this time.

of course i would prefer a re-built head shipped to me first, so my car isn't down for a week of shipping, 2 weeks of re-building, another week of shipping and then the re-install time, but he didn't have another n42 in stock so that's kind of what i've got to deal with.

we discussed the setup geometry, and while he felt it wasn't critical that the wipe pattern was dead center, he agreed it should certainly stay within the area of the pad and not fall off onto the rocker casting. his opinion is that the "dead center" wipe pattern was an "internet myth" and that he's built hundreds of heads without worrying about matching rockers to the cam and centering the wipe pattern with no problems to date. he was clear that my particular head setup was unacceptable and promised to re-do the work.

i'm going to give him the opportunity to make it right and sincerely hope that i will be able to post to that effect when the new head comes in. you can be damn sure i'm gonna get a sharpie and check the wipe pattern before i install it though...

[Zed Head]

At least you got to drive it for a little while.  I get the impression that the guy is kind of a BS'er.  This quote just goes against all that I've ever seen about the L series heads - " built hundreds of heads without worrying about matching rockers to the cam and centering the wipe pattern with no problems to date".  

 

On the valve seals, if he didn't use the little straws to protect the seals during installation, he could have cut them.  Maybe another internet myth.

 

Also noticed that he talked to you like he rebuilds the heads himself, but the eBay site says thet they're rebuilt by a professional machine shop.  Same company, but different stories.  He even told you hundreds, but says dozens below.  The Datsun Parts LLC disclosure is at the bottom of the eBay ad.

 

"*THESE ARE REBUILT AT A PROFESSIONAL MACHINE SHOP THAT HAS SEVERAL YEARS REBUILT DATSUN HEADS.  I HAVE SOLD DOZENS OF THESE WITH PERFECT EBAY FEEDBACK. **"

 

http://www.ebay.com/itm/Datsun-Z-240Z-260Z-280Z-ZX-Rebuilt-N47-Cylinder-Engine-Motor-Head-1976-1980-/151491312445?pt=Motors_Car_Truck_Parts_Accessories&hash=item234595fb3d&vxp=mtr

 

 

Sorry, hope I don't kill your interaction.  Send a PM if you want to keep things quiet for a while and I'll edit this down.

[Zed Head]

Came across an interesting thing on youtube and couldn't find a better place to post it.  Let me know if I'm causing problems.

 

Comment #8 says 100% money back even after two years - 

 

https://www.youtube.com/channel/UCgnW-7w6pgmMS_avX_5t-YA

[rossiz]

he was very reasonable when i called him, and without any arguing he immediately offered to re-build the head, so i'm gonna take him up on that offer. 

 

it's been very cold (for seattle) and we just got a new puppy (9 wk. old lab-border collie mix) - the combined effect being that it's much easier to be motivated to stay in the warm house and play w/little pup than to pull the head off the z... but i will get it done this weekend for sure and get it sent back for some love.

 

of course when it comes back i'll give it a good check and let all know how it looks.

[rossiz]

pulled the head this morning - only took 1 1/2 hrs and probably could've been done much faster if i had a helper. it actually surprised me how easy it was to do this time vs. the first time, and despite the fact that i'm doing a bunch of work that i shouldn't have to be doing, it was a rather pleasant morning wrenching due to the following:

1. none of the fasteners were rusted/stuck/broken/missing
2. i have a header vs. the oem exhaust manifold, so i could actually see the lower studs
3. i have all the tools i need (u-joint socket extension is a godsend!)
4. i now know my way around the engine bay
5. it wasn't raining... that hard (love seattle winters)

off to get some packing materials and get it in the mail today!

[S30Driver]

Good job Geoff!

I can't believe they don't have a head they can cross ship for you, maybe one with an internally oiled cam.

 

Did you ever do anything with your clutch...

 

(remember a helper is but a IM or phone call away)