Datsun Roadster Forum-311s.org

OK boys and girls,
I'm about to put everything back together and wanted to throw a quick summary here to make sure I didn't miss anything as I've only pulled the head on two motors in twenty years. If you recall, I dropped a valve seat a while back and pulled the head to correct the problem. While I was at it, I picked up a set of ceramic coated headers from Mike Young, had Rebello install smaller exhaust valve seats, intake seats and their 'custom ground' cam and will be installing an old set of solex's I came across a while back on eBay. Rebello suggested I switch out the 34 chokes to 37 which I will be doing as well. I have looked around this site and the internet in general and there is good and not so good info out there and doesn't seem to be one sticky for the process. Just to verbalize my process here...this is what I think is the right order...correct me if I'm brain damaged:
- I pulled the head not at TDC so I need to rotate the motor so the #1 piston is flush and the mark on the crank is at 0.
- I'm going to wipe down the block surface to remove any sludge and left over gunk. Does it need to be scuffed?
- I grabbed the full gasket kit from datsunparts.com and will use the included head gasket. I also purchased the head stud/nut kit but missed the part about lube. Is there a local O'Reilly equivalent? And it appears the torque spec is 80 ft/lb but I haven't found the link to the order. And do you start at 60, then 70, then 80?
- Rebello has the cam at TDC. I'll install the head and then he mentioned the chain should be tight on the driver side...is there a certain number of links or technique to make sure I don't hose the cam timing?
- Installation of chain tensioner, thermostat housing, (is there an O'Reilly recommended equivalent thermostat out there?), valve cover seem obvious.
- I'll install the new intake/exhaust gasket and Mike suggested a glop of RTV grey around the water jacket holes (engine or manifold side of gasket?).
Any other helpful hints/tips? I'm not looking forward to getting the nuts back on the carbs again...those were a pain on the SU...hopefully the Solex have 1 mm more clearance. I'm also pulling the solex's apart to clean and service them as they look like they've been sitting in a field so any insight into that is greatly appreciated. At Mike's recommendation I picked up a flex exhaust piece from the local O'Reilly and am going to fab the exhaust connection with a little help from a grinder and the local welding at the nearby exhaust shop. Thanks again to all and this forum for all the help.
Cam

My ARP studs were 80 ft/lbs and I used the ARP ultra torque. Summit Racing sells some as does Dean.
ARP claims there is not an equivalent lube. I torqued to 50 all around and then 80. Seems to
have held up so far. A stroked R16 with aluminum head. I also used a thread sealer (permatex into the blocks) and made sure
the studs were seated in the bottom of the block. Same block as yours.

Regular moly grease is a fine substitute - it's what I use.

Actually - now that I look back I realize I did not buy the ARP head stud kit because I measured the head studs and they seem to be the later .702 upgraded units. I've seen a lot of people rave about the stud kit...is the consensus that these are pretty critical to ensure a good head gasket seal? The head bolts look clean and I could clean up the threads and be on my way but obviously don't want to risk a head removal if that's a possibility.

I like the studs in general, but they are certainly not an absolute requirement. The factory bolts will work fine if torqued properly. (most engines have bolts)

The one time that the stud kit can be a problem is if a head was warped significantly.

In this case, with either an end-to-end warp, or a twist, even once machined flat, the original bolt holes in the head will be headed off at various angles relative to the block. This can cause a major binding situation with the studs.--- The bolts are more forgiving than the studs regarding this situation since there is more clearance in the head thru-hole, than with the fatter studs.

Sometimes the head is easier to remove with bolts rather than studs.

Other than that, I do like the studs.

j

Run the bolts. or give Dave Rebello a call and see what he says. Since I'm guessing the block is still in the car, installing the head is going to be the biggest PITA you can imagine. (I hope you have long skinny arms and small hands so you can reach the rear inner nut for the exhaust and intake that resides under the #4 primary tube.) If you can't get that tight, you will have a coolant leak. As long as you have a clean surface on both the block and head, things should seal nicely (assuming you are using a Nissan head gasket) I wipe my block and head with acetone and let it dry, then assemble. My trick with the gear and chain is to install the gear and chain, then install the tensioner, if there is space to add a spacer, I will.

If you need a hand, I might be able to assist next weekend. (Busy autocrossing my car at Sears Point this weekend.) Let me know.

Will

Regarding the nuts and washers for the intake/headers, I used a telescoping magnet with a washer or nut on it and found you can actually start them on the threads that way. And then use an extensions/u-joint/socket to tighten completely. At least its not a 240z

I'm a bit overweight, I'm not tall, and I have big arms. I don't understand all of the griping about the intake /exhaust studs. They aren't that bad. Put on your big boy underpants, grab a 1/4" socket set, and get to work.

Haha...thanks guys. I will probably bitch a little as getting everything underneath off required me to go have a beer halfway through.

Will,
I'll gladly take you up on you offer if you have the time. When are you auto crossing this weekend? Maybe I can sneak away from the kids to check it out for an hour or two. It would be fun to see a roadster in action.
Cam

I put my manifolds on before I put the head back on. That way I was dame sure they were on right.

It makes the head a little heavier so you need some help to drop it on - but it's possible. Obviously it's not as easy to line up the head when you drop it on there but saves a lot of headache too.

HTH
James

Kinda wondering why the would put smaller exhaust seats in...

I'm with you Greg, I was under the impression that U20 intakes were great albeit the exhaust needed work but smaller seats?

Dave at Rebello said after 50 odd years of tuning they found the issue with the U20 head was they were not getting enough velocity through the head and by reducing the exhaust seat size they were able to get sizable gains on the dyno. I can remember the exact figures but it was pretty crazy on some setups...like 10-15%. Check with Dave for actual numbers but I decided to go with his advice in this one. I'll give a butt dyno report when I get it back together.

Maintaining or increasing velocity is definitely an important consideration. Lookin forward to hearing more!

Dave knows his stuff!