Found this while replacing head gasket

[Silky_Johnson]

Thanks Hainz. I'll do the wipe pattern tomorrow and report with results.

 

It wouldn't surprise me if they didn't install appropriate rockers/valve retainers/lash pads/springs. Everything in this car looks like it was done in some teenager's parents' garage (sorry young folks). Perhaps that's all the noise I've been hearing under the hood?

[Sealik]

While you're at it....measure the cam/calculate lift

[banzai510(hainz)]

your springs look like thicker aftermarket. I just cant tell the lash pad set up. Lookinng at the glare of the other rockers they dont look like they are running over the edge..So they might be Ok. I learn never to rely on anybody else unless all they do is Datsun heads/Pinto heads ect......

 

But You need to ck to to be sure.

 

I would oil the shit out of that cam right before start up.

[Sealik]

your springs look like thicker aftermarket.

 

Yeah....has 1 less coil, which are leaning the opposite way...compared to stock

[Silky_Johnson]

While you're at it....measure the cam/calculate lift

 

This is going to make me sound like an idiot, but how do I measure the cam? (I suppose Ratsun is going to confiscate my car now...) Just trust me when I say I'm not a hack. I don't have any real precise measuring tools outside of feeler gauges, but I can by something. While I'm at it, what should I get (for measuring the cam), and where should I get it?

 

I would oil the shit out of that cam right before start up.

 

:thumbup: This I can do!

[Sealik]

Carefully measure the widest and smallest part of a cam lobe with some cheap digital calipers....about 10 bucks.

Subtract one from the other, multiply that by 1.48 = lift

 

 

Here's an example

1.542-1.217 = .325 x 1.48= .481 lift.

[Silky_Johnson]

Carefully measure the widest and smallest part of a cam lobe with some cheap digital calipers....about 10 bucks.

Subtract one from the other, multiply that by 1.48 = lift

 

 

Here's an example

1.542-1.217 = .325 x 1.48= .481 lift.

 

Easy enough. I'll report results tomorrow with the wipe pattern.

[Sealik]

Also....you could leave the rocker in place to do a wipe pattern.

Just rotate the cam (lobe straight up) until you can access both sides of the rocker with a felt pen.

Clean the rocker and mark at least 3/16 inch up from each edge.....confirm lash....rotate cam/engine.

If you do pull the rocker....have a look at the underside of the lash pad. Stock pads will have 2 slots cut in

Looks stock....other than the cam(?)/springs......but....

[datzenmike]

 

Hainz is right. There is hardly any back side left on the lobe.

 

As to compression ratio always err on the lower side, I don't mean go lower, just that if you have two choices pick the lower of the two. If you still want to run an 87mm bore try the 1mm oversize dished L28 pistons. This gives an 8.92 compression which will definitely run on pump gas even in hot weather. You can always shave the head to bring it up above 9. Half a mil or 0.020" should give around 9.2 on a peanut.

 

Generally each point of compression increase adds about 4% more power because of increased efficiency converting heat into work. On a 100hp engine going from 8.5 to 9.4 you should get 104 hp. This becomes less if your compression is already high. A 10.5 going to 11.5 will be much less than 4% as it is already mor efficient. These are very rough theoretical measurements and to take advantage of increased compression higher octane gas might be needed and timing changes etc. etc. but roughly 4%. So... you have to ask yourself is all this bother and expense, high octane gas, blown gaskets? wear and tear on parts worth it for a street motor? For a race motor the answer is yes because it's in a different world. It only has to last for the race or the season and gets rebuilt. Money isn't a problem. There are spare engines. Every hp gained could be the difference between a win and being trailered.

[Silky_Johnson]

Carefully measure the widest and smallest part of a cam lobe with some cheap digital calipers....about 10 bucks.

Subtract one from the other, multiply that by 1.48 = lift

 

 

Here's an example

1.542-1.217 = .325 x 1.48= .481 lift.

 

Just measured cam and calculated lift at .482.

[Sealik]

Just measured cam and calculated lift at .482.

 

Well....you should have after market 180+ lash pads in there then.....and retainers to match

Doesn't look like it though....thus the..."Perhaps that's all the noise I've been hearing under the hood? ".....

 

Lobe is running off rocker...wipe pattern is NFG?

[banzai510(hainz)]

]Just rotate the cam (lobe straight up) until you can access both sides of the rocker with a felt pen.

I though of this after the fact!!!!!!!good idea.

 

to measure the cam lift measute the tall part then ,easure 90 degs from this. this will be called lobe lift then measure by 1.48.

 

just to let you know youll minus the valve lash also. say .008/.010

 

you need a timming/degree wheel to measure duaration. But who cares. get a mirror ans maybe thers a number on back of the cam. or take a photo and show us. hopefull its plugged also in the center.

 

Go for the lower compression notor so you can actuall drive it all the time and spend the money on sidedraft carbs!!!!!!!!!

 

I say dont waist time on a high comp motor to just run a weber DGV

 

 

PS I would put the timming on Cam sproket position #2 as a starting point

[Silky_Johnson]

I just finished installing new valve stem seals. I suppose this job would have been a little easier without stiff aftermarket springs... I'm tired. I noticed that on one valve, it was missing the washer where the spring seats on the head (aluminum). I made sure to put a washer in to protect the aluminum. I tell you, everything on this car was about 90% done. EVERYTHING.

 

 

 

 

 

As to compression ratio always err on the lower side, I don't mean go lower, just that if you have two choices pick the lower of the two. If you still want to run an 87mm bore try the 1mm oversize dished L28 pistons. This gives an 8.92 compression which will definitely run on pump gas even in hot weather. You can always shave the head to bring it up above 9. Half a mil or 0.020" should give around 9.2 on a peanut.

 

Looks like I've got three votes including myself on compression. I agree that I definitely want a streetable motor. So what year of L28 pistons should I be looking for? Hopefully they're as cheap as the flattops, which were only $35ish a piece including rings. And another question: should I bore out to 87mm, or should I go more or less? Just looking for opinions on how far out I can and/or sould safely bore.

 

Well....you should have after market 180+ lash pads in there then.....and retainers to match

Doesn't look like it though....thus the..."Perhaps that's all the noise I've been hearing under the hood? ".....

 

Lobe is running off rocker...wipe pattern is NFG?

 

I present to you, my wipe pattern in blue sharpie (sorry, didn't have black). And by the way, I considered wiping my butt and taking a picture of the toilet paper as a joke. Consider yourself spared.

 

This is from an exhaust valve adjusted to .010 (cold of course).

 

 

 

 

 

 

you need a timming/degree wheel to measure duaration. But who cares. get a mirror ans maybe thers a number on back of the cam. or take a photo and show us. hopefull its plugged also in the center.

 

Go for the lower compression notor so you can actuall drive it all the time and spend the money on sidedraft carbs!!!!!!!!!

 

I say dont waist time on a high comp motor to just run a weber DGV

 

 

PS I would put the timming on Cam sproket position #2 as a starting point

 

Here's the back of the cam. Not very interesting.

 

 

As I said before, I'm not set on high compression. If around 9 will be more streetable, then that's what I'm doing. And by the way, I don't need to save money for sidedrafts. :D

 

[datzenmike]

I think the important wipe pattern is on the rocker arm. Has to be in the middle

[Silky_Johnson]

I think the important wipe pattern is on the rocker arm. Has to be in the middle

 

Crap.

 

 

[Silky_Johnson]

I'm not certain that this is how you measure the lash pads, but what the heck:

 

[Sealik]

Here's a wipe pattern on my head.

The whole rocker was 'slathered' with a felt pen...cam rotated.

Notice the little sliver of black remaining on the edge of the rocker?

That is good....as long as you have the same amount of 'black' remaing on the other (back) side of the rocker

Pattern is centered....

 

 

 

Stock lash pad on left......after market (.180) on right

 

[Sealik]

I'm not certain that this is how you measure the lash pads, but what the heck:

 

 

Yup...not stock......220 pads

Which means you also have after market retainers....that is good

Now for the wipe pattern....centered?

[Silky_Johnson]

Go back a page. Looks centered?

[Sealik]

Go back a page. Looks centered?

 

Ahhhh....I see.

 

I would put a little solvent on a rag and clean the rocker and lobe up....slather the whole rocker and do another wipe.

And ya......Save the :poop: wipe pics........ :D

 

 

 

 

Every rocker will have to be done.....if there are no springs installed, you could put a straight edge across your valve stem tops.

They should all be close.....but if 1 or 2 + are a little higher or lower you will need to adjust with a different thickness of pad.

It's just a heads up.....knowing ahead of time while doing a wipe.

For me, it was all 180 pads......but when I put a straight edge across I could see 1 stem was a little low.

About .010.....which led to a thicker 190 pad. Wipe pattern confirmed this.

[datzenmike]

Damn Doug, you're a pro at this. I just drive them. Well good to know someone who can tutor me if I build a head.

[Silky_Johnson]

Got it. I'll do every rocker, but some other night. I'm too dang tired from wrestling with the springs today.

[Sealik]

Damn Doug, you're a pro at this.

 

If wish......guess where I learned it 'all'....????

Hmmmmmmm????

 

 

 

 

Wait for it......

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RATSUN....FTW.... :thumbup:

 

 

Hainz, datsunwizard and many others....including you... :)

 

Got it. I'll do every rocker, but some other night. I'm too dang tired from wrestling with the springs today.

 

Yeah...that style of valve spring compressor somewhat sucks

 

 

I have this....

 

And a large C-clamp style for when the head...... cam is removed.

[banzai510(hainz)]

Ok on Earlier pages you sad his head came back from the machine shop.

Was it totally taken apart? if so your saying a spring seat waser wasnt installed??????this isnt good. It will eat into the head

 

But going by the one photo of the rocker that you taken a photo of I would say its centerd enough long as it not rooling of the rocker. center is PERFECT but I dont think the cost of buying of size lash pads it going to make a big difference

 

I can see thes look like used rockers as that center line (wear)is seen.

[Silky_Johnson]

Ok on Earlier pages you sad his head came back from the machine shop.

Was it totally taken apart? if so your saying a spring seat waser wasnt installed??????this isnt good. It will eat into the head

 

But going by the one photo of the rocker that you taken a photo of I would say its centerd enough long as it not rooling of the rocker. center is PERFECT but I dont think the cost of buying of size lash pads it going to make a big difference

 

I can see thes look like used rockers as that center line (wear)is seen.

 

The shop just tested the valves for leaks. I believe they took the cam out, but they didn't mess around with the springs. I'm 99.9% certain they aren't to blame.

 

As far as I know, the spring washer hasn't been installed since at least two owners before me (3 years ago). The previous owner that I met had driven the car for about a year never opened up the engine. He did a couple of things, like the alternator and clutch master, but he couldn't even confirm if it was a peanut head or not. My guess is the guy before him hacked it all up. It didn't look like it had eaten into the head very much but with these kinds of tolerances, looks don't mean much.