L20b u67 head

[8m0untainman8]

The cam rotates, very smoothly before tightening down, the last cam tower just binds when i tighten it, the little studs to guide the cam tower came out with it and probably just need to go all the way back in.

[Stoffregen Motorsports]

Good, that's a start.

 

Make sure the dowels are not crooked. If they need a tap to get in place, do it gently, then let the tightening of the tower bolts set them in place.

[Crashtd420]

I don't know if this will help or not but do you have the towers in the same location as before?

 

Stroffgren has you pointed in the right direction..... you want those towers perfect.....

My old head suffered damage to the tower and cam because previous owner didn't install properly.... it's worth taking the time to make sure this is right....

[Stoffregen Motorsports]

One thing to be clear on. If the towers aren't seating properly, don't try to tighten them into place with those wimpy 8mm bolts. Give them a tap with a hammer (on top, with the cam installed) to get them down.

[8m0untainman8]

Ill spend as long as it takes me. Theyre 12mm though.

i can tighten the front two with no binding, just the back two, the dowels came out with the third tower, im assuming thats what is causing it to bind, im going to use a rubber mallet probably, unless otherwise told.

[8m0untainman8]

There's only one bolt i cant tighten, all the others will tighten without causing binding XD sooo close

(Its the third tower, driver side bolt) how hard can i safely *tap* the towers with a rubber mallet?

[Stoffregen Motorsports]

With a rubber mallet, you should be able to smack them pretty hard. Down, that is. If you need to smack them side to side, which you should do, then not as hard.

 

So when you say you can't tighten it, you mean the threads are stripped? If it's stripped, then that's another problem. I would heli-coil it or time-sert. If you need to oversize it, you're on your own. I've left the short ones out completely, as the head bolt holds down that side of the tower.

 

The bolts are 8mm, but they have a 12mm hex head. Bolts are measured by their thread, not the hex on top.

[8m0untainman8]

I cant tighten it without the one bolt causing binding, so ill give it a go with the mallet again.

[8m0untainman8]

Okay, this is dumb, but when all the bolts are tight should there be no resistance at all? Or will there be some resistance.

[Stoffregen Motorsports]

PM'd you.

[flatcat19]

Did you just strip a cam tower bolt?

[8m0untainman8]

No lol

[datzenmike]

Inspect the underside of rear tower and the head surface for dirt or something. It could be sitting high and tightening #3 pulls down on #4 and it binds. For that matter check them all.

[Stoffregen Motorsports]

He's got it figured out. Sounds like it's spinning freely now.

[Crashtd420]

Just takes time an patience.....

[DHale_510]

Now he needs to understand that the lash pads come in many thicknesses and are critical to the assembly. They need to allow a centered wipe pattern on the rocker to keep them from cutting into the cam. They change with a reground cam, resurfaced rockers [this avoids the mismatched confusion trouble], reset valve seats, replaced valves, resurfaced heads, and maybe just wear. The poster started with a problem of a missing lash pad and these problems were never addressed.

If your machine shop doesn't understand lash pads and thinks the threaded adjuster is there to make all of these adjustments [like  Chevy], you need another machine shop that knows Datsuns and Mercedes.

Stoffergren maybe knows this better than anyone else on this list. He has setup several heads for me in the past. Trust him.

Dennis 

[Stoffregen Motorsports]

Thanks Dennis. And you're exactly right. It is a steep learning curve, but once you've done it, it's just a matter of having the right tools and an assortment of lash pads.

 

Hell, it took me years to be able to hone my Datsun skills. And then it took even more years to stop having dreams about Datsun stuff. Actually, I still have one recurring dream where I'm back at work for Dave Rebello or we're working together in my shop. And in these dreams, I'm usually late to work...(!?) Having him as a teacher is something I will always be grateful for.

[distributorguy]

Steep learning curve?  Don't you just measure the difference in size of a factory base circle and that of the reground cam, then add that to the factory lash cap sizes, minus the change in valve height from cutting the seats?  Easy, right?  Or figure out the difference (.110" in the case of my Bonneville motor) and have valves made with longer tips so you can use standard size caps.  Yes, there's room for the lash cap to stay put with longer valve tips!  

[datzenmike]

The average Datsun owner doesn't get longer valves to avoid using taller lash pads.

[Stoffregen Motorsports]

Steep learning curve?  Don't you just measure the difference in size of a factory base circle ...

That was an attempt on my part of encouraging him.

 

To someone who hasn't done it before, what you said translates as " take the ramistan and divide by the hypotenuse, add and square the multitudinous apoplexy and finally you'll end up in Chicago."

[banzai510(hainz)]

same as a dentist pulling a tooth thru ones asshole.

 

I have lots of stock lash pads if he needs them and live in south seattle area

[8m0untainman8]

Okay. So if and when i plan on getting head work done again, I'll be sure to go to a shop that knows datsuns. Ive messaged a couple of you about the chain tensioner, and thats still where i am. Lol. This is all good advice and im keeping track of it, but i cant get the timing chain cover off, maybe im being too careful.. but until i get the timing chain right the head is on hold.. my truck is my biggest priority right now.

Wait is that a shortcut to get to chicago?

[Stoffregen Motorsports]

"It's 106 miles to Chicago, we got a full tank of gas, half a pack of cigarettes, it's dark... and we're wearing sunglasses." - Elwood Blues

 

You still can't get the front cover off? Did you get all the bolts holding it on? There's one behind the oil pump that many people miss and a few of the water pump bolts go through to the block as well. It's also a lot easier to get off if you have the pan dropped.

[banzai510(hainz)]

I thought wediscussed this in PM what you needed to do?

 

ok you have to take the distributor and oil pump out to get the fromt cover off. water pump bolts.  you have gaskets sets ready, permatex?

 

One needs to break the big 22mm bolt? you do that? hard to do with the head off now. as I showed in my vid you seen but still can be done.

[8m0untainman8]

Everything is off of the front of the motor, rad out, half the bolts out of the oil pan (i think there was epoxy on the front corner bolts like someone had been here before), i ordered gasket kits, it just seems extremely snug still, like no budge even. Mind you my whole engine had a black layer about 1/4" thick everywhere but the valve cover, even that was grimy. Im pretty sure i got all the bolts even the hiding ones.

I suppose it could be bound from heat, but before i assume anything il look for more bolts, and loosen the oil pan more, i guess lol.

Im working out of a friends shop and need to go check on my house so may not make any progress until friday sadly.