Datsun Rocker arms?

nncoolg · Post by **nncoolg** » Sat Nov 19, 2011 8:25 am

I was wondering if anyone has had much experience with any of the Datsun OHC engines? In that I suspect that maybe one may have rocker arms that my work on the EA82 and have adjusters in the half-spherical end that sits on the lifter?
I am thinking of welding up some HLA's if I can find a rocker arm that has an adjuster in it...
thanks.

littlewhiteute · Post by **littlewhiteute** » Sat Nov 19, 2011 8:38 am

I wish you good luck in finding an appropriate rocker arm.

Consider the offset the rocker arms have.

I'll assume you'll be getting the cams reground to a solid profile?

Gannon · Post by **Gannon** » Sat Nov 19, 2011 10:00 am

Why cant you just use shims with your solidified lifters.

Slightly off topic.... Is your dad still looking for some L series front rotors? The ones I though I had went with a shell to the scrappy, but I know a guy with an L series that is sitting on blocks in the process of being stripped. I'll be out there today so I'll ask him

nncoolg · Post by **nncoolg** » Sat Nov 19, 2011 11:21 am

Yes, that is something that could be done, but would require removing & refitting the camboxes to get the gaps set. I am hoping to get some rockers with an adjuster in them.

YouTube · Post by **El_Freddo** » Sat Nov 19, 2011 12:20 pm

The Datsun OHCs that I've checked out don't have an adjustable arm, they've got a solid lifter that's adjustable. This is what I used to make my solid lifters.

They're a pain in the arse to adjust - you have to measure the gap, remove the cam box, adjust to what you think is needed then replace the cam box, measure and repeat until you're happy with the required gap, I went for 7 thousands of an inch.

Once set they're pretty good, I had mine on an MPFI and wouldn't do it with one of them again - power really only came on from 4000rpm and beyond. I think a carbie EA82 would be a better setup. I also didn't know about the difference between a HLVA and a soild lifter cam profile at the time...

Worth the effort once set up I think, but I'm not going to be doing one again...

Cheers

Bennie

nncoolg · Post by **nncoolg** » Sat Nov 19, 2011 8:25 pm

Yes, I can imagine it would be impossible to move adjusters in the place where the HLA's live from the 'top', hence me wanting adjusters on the rocker arm.
What was it that caused yours to fail?

YouTube · Post by **El_Freddo** » Sat Nov 19, 2011 8:47 pm

nncoolg wrote:What was it that caused yours to fail?

My lack of attention to detail. The way I made them was to find a nut that fitted the thread of the solid lifter from the datto, buy 16 of them and have them turned down to fit inside the base of a HVLA, two per HVLA.

The problem was that for some reason the place that turned the nuts down only gave me 15 - so one of my lifters only had one nut holding it in place. After 2000km the bottom of the lifter with only one nut started to swivel, causing the valve it was servicing to not properly operate.

The other thing I found was that the lifters internal diametre were all different - this I think was due to wear and it didn't occur to me earlier when I had the unts turned to fit, so some were half a bee's dick too small and had a tiny bit of movement that I wasn't worried about.

But it's a mod that I wanted done before heading off as I'd heard good things about it, just not on the MPFI... I should have at least ground down a nut with the grinder, it would have been better than nothing.

Other than that they went pretty well after 4000rpm, before that it was "ah, I'll get there" sort of performance.

Cheers

Bennie

nncoolg · Post by **nncoolg** » Sat Nov 19, 2011 8:50 pm

Ahh, I see, so one screwed itself loose enough to fall off the valve then?
Im interested in the 'under 4000rpm' thing, do you reckon the car went better with HLA's at normal rpm?

YouTube · Post by **El_Freddo** » Sat Nov 19, 2011 9:11 pm

nncoolg wrote:Im interested in the 'under 4000rpm' thing, do you reckon the car went better with HLA's at normal rpm?

I was running an EFI EA82 - the MPFI as it's known, so the computer wouldn't have been programmed for the extra duration of the open valves and thus would have been wasted on the EFI setup.

The hydraulic units were much more drivable with the MPFI. That said I've seen a carb'd EA82 go very well with the soild lifters, only I didn't drive it so can't comment on how it went below 4000rpm... One way to find out though if you're really keen.

Cheers

Bennie

steptoe · Post by **steptoe** » Sun Nov 20, 2011 12:04 am

Neville, you have a little iron and alloy snail that is so easy to add a few more pounds boost - easy compared to attempting to make solids

why....?