New World Datsuns...

I'd suspect head gasket issue as well. Is the cooling system pressure spiking as well? On Subarus with early stage internal gasket failure this is how I'd verify; 1. Install cooling system pressure gauge. 2. Let engine come up to temperature. The gauge normally reads a few psi as it warms. 3. Wop the throttle a few times and watch the needle jump each time as cylinder pressure is introduced past the failing gasket.
The combustion gasses add heat to the coolant and create intermittent airlocks and hot spots. In the early stages it causes all sorts of weird symptoms. It's an awkward stage to diagnose but eventually gets bad enough not to ignore.
Good luck.

Yeah, it's about the only thing that makes sense. I do remember re-torquing the head bolts when I refreshed the engine. But, 1983 head bolts with approximately 120k on them, there's a good chance one or more of those might be weak. I'll feel much safer with a head stud kit. Every L motor I've built since 8 years ago I've used those. Never had an issue since.

SHIT!! You know what? I ordered the head studs already. Then I remembered I have a brand new set on the L motor I'm not using for Wynona that's sitting on the furniture dolly. Could have just yanked those out of that engine. Balls. Oh well. I suppose I could always return the set I ordered. Then again, if I do build another engine, I guess I'll have a spare set of hardware. It's $152 for the head stud kit. Not super expensive, but not exactly cheap either.

On the plus side, I think I finally figured out the fuel leak issue on the RX7. Vacuum secondary housing/diaphragm/bowl to vacuum hole gasket leaking. For some reason I never suspected it last year. Makes sense. Carb ran fine but leaked fuel. Have a new assembly coming, and an adjustable assembly that's all metal. Think I may replaced the plastic quick change with that one. Then all I have to do is install camber plates on the RX7 and the wife's car will be ready for autocross when covid-19 is over.

Check out the mask the wife made me! It has race cars!!

And here are the pics of the Racing Beat Holley carb for the street port 12a. The symptoms from that last year was fuel leakage, kept thinking the bowls but it wasn't the bowls. Carb ran fine, just gassed us out in the cabin. The amount of fuel leakage was dripping off the bottom of the mounting flange. I had rebuilt it over the winter, but couldn't see how I missed anything on the rebuild. Looking at the black gunk on the front side, I think it was hiding the fact that it was fuel coagulation and just seeping down off to the side due to the fan blowing it back. Not sure, but either way, I didn't regasket it, so that will happen in a week when I get the parts. Then I can do more testing.

While I was at it last night, I rewired a light above my work bench and tied it into a new electrical outlet. Only been meaning to do that for years. I really need some new light fixtures. The basement has recessed boxes and they just don't throw crap for light.

Up next, attempting to reassemble the transmission I took apart many moons ago. It's the KA tranny I had a modified L bellhousing clearanced out for. Once I put it back together, it will go in Betty White for some much better strength and gear ratios.

Lol

Ok, so taking off the head today. I was debating just having the N47 head I have laying around rebuilt instead of the P90A. The only problem I found is the N47 has steel liners, whereas the P90A is semi-square port without liners. N47 would also be (allegedly from the internet digging) slightly higher compression which wouldn't be a problem. Either way, I think I'm going to go with the stock head, convert it from hydraulic so I can get rid of the damn hydraulic lifter clicking, and probably install my 260 grind cam. That was the medium cam for Wynona. I need to check with Delta and make sure that's a good idea or not. I'm pretty certain it will work. I'm certain the N47 will work, but non-liner head for turbo application will probably be a better idea.

Alright, the 918-260 grind I had for Wynona has fairly small overlap, enough that it should work fine with the turbo. So that's a go, along with the solid cam followers. Got the head off, that was a giant pain in the ass! Especially sneaking the extension and wobbly through the heat shield. Trying to upload pictures now, wait for it!!




This is the picture I sent Mohammed this morning when he didn't show up at 8, lol. "Where's Mohammed Dad?"













Fortunately Mohammed DID show up! Weasel was happy! And a big thanks, Mohammed has been helping me out a ton, we've been getting stuff done! He worked on the wagon while I did the head job, though I definitely needed a second set of hands to get the manifold bolts off inbetween. I worked the wobble onto the bolt and had Mohammed articulate the ratchet. Times like those, I wish the L series was crossflow.

The red oil looking fluid in the block is Marvel Mystery Oil. Had some antifreeze sitting in the bores so I sopped it up as best as I could and then put some MMO down to make sure the water didn't make any rust annoyance.

Alright, so I got the head back, held pressure no problem. I'm also going to do a few things while it's off. First, going to convert it to regular solid lifters using all the head hardware from the old Wynona motor. Medium cam (checked, Delta says it should be ok with turbo), Schneider valve springs, Kameari cam gear. Found this helpful video for converting the head. I'm using the 18mm inserts, cheaper and easier. I also don't have any installation tool, but I'm doing research and I'm certain a grade 8 18x1.5mm bolt will work just fine to roll the last threads and lock the insert in place.

While we're at it I'm going to relocate the piping and either do a water to air intercooler, or an air to air. Haven't decided which, but ordered a 50mm/2" intercooler piping kit off fleabay that should work just fine.

What? Simple head stud install job? Naaaaawwwwww, that's not how you do it in a Datsun!!



Thanks to this guy, very nice video.

So I just broke the head. I forgot about this video, pretty sure he mentions doing by hand. I though the electric impact would be a good idea. Well, it's not. I broke out one of the pedestal bottoms. Cracked one other. Had them almost all done too. Had one more to go. I'm not sure if this can be fixed by welding or not. All I know is I'm super pissed I didn't think about this better. What I found is my inserts go in the head much farther. The threads start a 1/4" down in the hole. Either way, same grabbing force, so shouldn't be a problem. But getting the timesert to hold is a bit of a pain. I had a couple where it wanted to walk back out. That's when the impact gun came in. I also used a regular bolt as an installation tool. Grade 8, should have worked. I'm wondering if the insertion tool is a little harder. My threads were getting a little cranky on the bolt.

Think I'll send dad a couple pictures tomorrow and see if he can weld it satisfactorily. Then I'm going to have to have it checked at the head shop again since it will probably warp a little unless I bring a block to bolt it down to. Fucking hell. I'm so sad and pissed off right now.

Lucky for me, it looks like my buddy is going to bail me out. He has an N42 head which should work. Going to go check it out today.

Don't break it.

Yeah, where were you last night dipshit?!

So the bad news is the N42 head turned out to be an E88 head. Not what I wanted, smaller valves, raises compression, good for NA, not for turbo, it's basically open chamber, not peanut.

Good news is I showed the pictures to my Datsun guru and he said it would be fine to weld those up, shouldn't affect the water jackets or anything else. I was going to bring it over to mom and dad's tonight to have dad weld it up (Datsun guru's heading out of town for AHRMA Nationals), but mom has the screaming shits (one possible symptom of covid) so I decided I would work on other things and wait until next weekend just to be safe. Homie can't build car crap if I'm quarantined for 2 weeks. That'll hit the pocket book. Hopefully mom doesn't have covid, but Coeur d'Alene is having a ridiculous amount of covid cases right now, so there's certainly a possibility.

Anyway, hopefully I'll have a better update next weekend. In the meantime I hope the parents don't have covid and I'm going to go weld a bung in the hardbody so I can hook up the wideband setup. Still haven't gotten that thing dyno tuned though I've had the ecu built now for 4 months.

If they're relatively healthy they'll be fine. I've had way worse hangovers than the strain we all got in my part of the state.

Glad to hear it's a salvageable wound. Worst case, you have all winter to find another.

Thanks, I'm hoping it's not covid anyway, they're on the old side a little bit.

Went up to mom and dad's this weekend and dad bailed me out. This head is a b**** to weld with the cast aluminum. Lots of imperfections and porosity we kept getting little tiny cracks and or holes. After a lot of effort we finally got rid of any leaks. You wouldn't think it would matter but the rocker stanchions have an oil port in them probably to keep them turning freely instead of having them iron in place and not be able to adjust the valves.

UPDATE: Had the head pressure tested. Not warped, no leaks. Good to reassemble. I may do that today, we'll see how motivated I feel.

Oh yeah, it gets better!! So one of the time serts I installed (the last one actually) wouldn't torque to 72 ft-lbs. It pulled the insert apart. Yeaaaahhhh. So now I have 11 rocker pivot bolts installed, and that last one to remove and re-install another time sert. Sooooo. I don't have a tool to remove and it looks like it'll be a bitch. I ordered a very large set of spiral screw extractors off Amazon just now, hopefully one of those will work. But suffice to say, the head will NOT be going back together today. Balls.

I wonder how cheap I can get a SBC locally. Hmmmm. If only there were more heads available that would be good for the turbo L28. I'm tempted to just put the Maxima head on, but steel liners, no good. Think I have an L26 head somewhere, but that's not internally oiled and the combustion chamber is too big. Only reasonable option after investigating another head is the P90 or P90A really. And good examples of those are about the same price as a SBC. I'm trying to be purist here, but I'm really getting annoyed not having parts availability. If I screw up a SBC part, I can order a brand new one. Ya know? It's getting hard to fight the power-to-money ratio.

Sigh. Oh well, I'll wait for the extractor and new time-serts to come and then see how I feel. If I can get it out and make it work, it'll still be fine.

So here's a thought. I'm going to attempt to get the head fixed so I can get the turbo motor back together. But damn if LS engines aren't cheap. Hmmmmmm. And they make mount kits for less than 200 bucks to mount them in z cars. And there are some for 900 bucks at my local wrecker that are still good engines. Hmmmmmmmmmmmmmmm. I hope the turbo engine works because it's far cheaper, I already have it in the car. However, if it doesn't....I may give up the purity for the Z car.