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P90a head F54 block correct head gasket


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In the process of chasing the exhaust gas in radiator, I pulled the head, gasket looked ok, found a couple areas that may have been a an issue. Anyway while looking over the gasket i noticed several of the head cooling ports on the manifold side were completely covered by the gasket. I pulled out my felpro, it had holes for those but was missing on hole on the spark plug side. Also had holes in the gasket on that same side where there were no ports. 

So what I think is the OE had missing holes in the gasket, the felpro had holes that did not match up with all the water passages either. 

Am I missing something? I have found a OE nissan gasket for the P90a head that looks like the old one, again missing all the holes on the manifold side. I figure I should go that way, even though it seems illogical. 

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There was a whole big conversation on Hybridz years ago about head gaskets and holes.  The end impression that I got was that not all of the holes were meant to be open.  You'd probably have to see factory original gaskets to know for sure what the engineers intended. 

The head design in general has uneven cooling as I understand things.  Cylinders 5 and 6 on the turbo engines are the ones that detonate most often.  People took extensive measures to try to improve the cooling, drilling in to the passages and adding a manifold to control coolant flow.  The funny thing was, as I recall, that the guys that got it evened out would just get detonation on all 6 cylinders at the same time.

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wow, there is a LOT of discussion in there. Tony D states more holes open the better , think that was the gist of it. 

I maybe getting ahead of myself here, will post up some videos of what I have and have found out. later.

Good news is the bores look great, and the head has less than .003 and that is only at the very end, not the middle. I still have to clean up the head surface, so that may even be false as I may have some residue left on that side. I did a diag check full length was about .002. Using gasket remover and plastic razors for the head, coming out well. 

other issues, the rust accumulation is horrific, I mean like mud like and a lot of it. the block also had one head bolt on the manifold side that fought me all the way out, the rest had nice break away feel. the one that was trouble as the rear dowel hole bolt. Lots of rust. I am pretty sure its a blind hole, so not sure how water could have gotten in there. There was evidence of a brown rust water stain on the side of the block right by this same bolt. Also the fire ring did not have the nice clean space between it and this same area. My guess is the exhaust gases were pushing past the ring and opening up a path from the water jacket, bolt hole, and side of head along the bottom of the gasket. that is what I think i was seeing. 

I bought a thread chaser to try and fix the bolt hole, have a super scraper on the way for the block. I am going to have to pull the engine of the test run stand and either get a shop to hot tank it, if they still do that, or I will pull the freeze plugs and see how much mud I can dig out.

 

 

 

 

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I dug into this a little bit deciding which gasket to use on my F54 and I decided on OEM.

My thoughts on the cooling holes is that Datsun was (forever) chasing unevenness in the cooling between cylinders and kept changing the size and existence of the coolant holes accordingly. And by the time they got the to end of the series (which is what you have), they had completely blocked off some of the holes towards the front of the motor with the intent of forcing more water to flow to the back of the head before heading to the radiator.

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sounds good to me CO.

Well I decided to just remove the engine from the test stand, will drain the oil and water (with head off), move on to the freeze plugs, and then decide on hot tank or DIY block clean/de rust. There is still about 1" of rust mud (poke s stick down the back water hole in the top of the block). Seems pointless to pursue continued work on the test stand, even if it passed the coolant test I would just tear it down afterward due to the rust issue. I will get the factory gasket, have that ready to go. 

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sounds good to me CO.

Well I decided to just remove the engine from the test stand, will drain the oil and water (with head off), move on to the freeze plugs, and then decide on hot tank or DIY block clean/de rust. There is still about 1" of rust mud (poke s stick down the back water hole in the top of the block). Seems pointless to pursue continued work on the test stand, even if it passed the coolant test I would just tear it down afterward due to the rust issue. I will get the factory gasket, have that ready to go. 

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Here are my (relatively disorganized) notes about head gasket stuff. Maybe something in here will be of help.

L24 and L26 versions - item #19: (From the old fische)
11044-E3100
11044-E3101
11044-E3102
11044-P3000
11044-P3001
11044-P3000
11044-P3002
11044-P3004 This number supersedes all the previous numbers
and is the final listing for the early motors and its used on 240 and 260

L28 versions - Item #18: (from the old fische)
11044-N4200 - No superseding listed on the fische, but was superseded after the fische

After the fische from other on-line sources
11044-N4200 - 09/1974 - 04/1980
11044-N4210 - 05/1980 - 02/1981
11044-N4220 - 05/1980 - 02/1981  (don't know why there are two of them. Might be turbo)
11044-N4221 - Supersedes all of the above


11044-P7900 - 80-82 GL (turbo)
11044-P7910 - 81-83 GL and non GL (everything 83 turbo and non turbo)
11044-P7911 - Supersedes all of the above

Looks like the 11044-P7911 may have been superseded by 11044-P9600

Part Number 11044-P9600 Replaces NLA 11044-P7900 11044-P7910 11044-P7911
The original gasket was made by NRZ Nippon Reinz
This gasket is made by Stone
It is for the original head/block combo on 1981 1982 and 1983 S130 280ZX"
And if you look closely at the gasket, you can see both the Stone logo and the Nissan logo

victor reinz 61-52115-00 (they list the same gasket for Z and ZX)

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Part Number 11044-P9600 is the one I went with, on the way along with an ARP cleaning tap and some new dowel (one got chewed up in the removal process). 

I just finished draining the oil from the block. Coming soon I will cover the oil passages and flip over for some prelim rust removal. just want to get the mud out for now, then will move on to full disassembly for more through clean out and possible electrolysis rust removal (still need to find a shop that I trust, if i can will let them use the method they suggest for cleaning out water passages.

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That's the same head gasket I went with as well (11044-P9600). I like the round holes for the head bolts better than the large oversize rectangular cut-outs of the previous version. My thinking is that I want as much meat as possible between the water jacket holes and anything else.

I got mine from Riley at Lynchburg. Out of curiosity, where did you find yours?

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And about cleaning out the block... I made a little adapter for a garden hose that shoots a thin jet and I was able to stick it deep into the core plug holes and flush junk out. Kinda like a power washer, but just at tap pressure.

Looks like this:
P1180151.JPG

P1180152.JPG

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2 hours ago, Captain Obvious said:

That's the same head gasket I went with as well (11044-P9600). I like the round holes for the head bolts better than the large oversize rectangular cut-outs of the previous version. My thinking is that I want as much meat as possible between the water jacket holes and anything else.

I got mine from Riley at Lynchburg. Out of curiosity, where did you find yours?

Parts for Nissans.com

says it was shipped today so standing by..

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whew LOTS of cleaning today. removed the side core plugs (left the front and back, they look perfect and I dont think I gain a lot of cleaning action there). start wit digging my fingers into the ports and dragging out the mud. After that I used a bent up small dia tube and dig deeper digging. Once i got most of the big chunks out and the remaining stuff turned into a slurry, out comes the garden hose for more flushing. repeat the steps a few times until I must have gotten out 90% of the junk. I know that does not mean a lot since the total amount of the junk was unknown so perhap 10% is way too much, but its not. I would say it has a typical amount of residue that any engine would have now. I implore any owners of spare engines, go out and knock out the core plugs and do this as a minimum, let the dry out and spray in some oil or WD or what ever float your anti rust boat, then tuck them away until you are ready to use the engine. I think its reasonable to assume that just draining the block via the plug is not good enough for long term storage. 

So what's next...

well I am back to perhaps trying scraping the head and block and installing the fel pro for another try. I will save the good gasket for later. the cylinder walls look great, and the leak down test tells me the bottom end it fine. I keep vacillating on doing a complete tear down. I think to help make the decision I will remove the pan and pull at least on con rod and one main to inspect for wear. I guess I could check for end play in the crank as well. 

I guess the smart thing to do would be to let a shop do a magnaflux on the block since I had some exhaust gas leak into cooling passages issues based on the chem test.  For some reason I resist the idea of a shop getting its hands on my block, prob since I have NO experience with using a machine shop...

 

 

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all cleaned up, had between .002 and .0025 gaps on the head and block, have to check the fsm but IIRC thats fine. 

Posting up a video now. 

Next up will be do I just bolt it all back together now and try it again, OR do more tear down. With the nice looking surfaces and how well it did on the original compression leak down test I am leaning toward the former. I could get it all back together in 1 day easy, and then swap back to the test stand in just a few hours. 

I will have to sleep on it.

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2 hours ago, Patcon said:

I think you try again before more teardown. Might be informative

yes,  my line of reasoning is the only issue was it seemed to be running hot but with all the crud that figures, and the exhaust gas in the rad. I had no odd bottom end noises and oil pressure seemed fine,  so no real reason to tear down. One thing i was reading up on cleaning out the oil passages, the ones in the top of the block for the head have tiny holes (restrictor plugs) wonder how do you clean that? Not going to bother unless i do a full tear down. 1st thing is start the engine  on the test stand, its the one with the MN47 head, I want to do a test again on it with the chem test kit, to act as a control subject and make sure the chem test is working ok. 

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 on full teardown I would have the block boiledo On full teardown I would have the block boiled clean. That should take care of the internal passages. It would help too to remove the galley plugs for cleaning.  Either replace them or drill and tap like we did on Cody's L20b

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Posted (edited)

huh core plugs are a bit of a problem, not sure but are the kits short the correct number of small plugs? I have 9 on the sides what i see are 7 in the kit. thought this would be a no brainer..

 

https://www.oreillyauto.com/detail/c/melling/hardware---fasteners/expansion-freeze-plug/expansion-freeze-plug-kit/f7a4da40e238/melling-expansion-plug-kit/mel0/mpe132r/v/a/6638/automotive-car-1979-nissan-280zx?q=expansion%2Ffreeze+plug%2Fkit&pos=8

Edited by Dave WM
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My machine shop had problems sourcing freeze plugs when they did the L20b in December. So it wouldn't surprise me if there was still some scarcity.

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Posted (edited)

Yeah, I don't know what the deal is, but the number and size of the core plugs is an issue. Seems like it would be simple, but it's not. Everyone seems to think that the same kit fits everything from 70 through 83, and that's just not the case.

Here are my (relatively disorganized) notes about freeze plugs:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
On the F54 block, there is a total of eleven freeze plugs required. I had originally said there were ten, but I edited this post to show there are actually eleven.

Nine 35 mm
One 40 mm
One 50 mm

I bought (a quantity of two) Sealed Power part number 381-8027 sets off rockauto Jan 2020

Each set contains 1-50mm, 1-40mm & 7-35mm plugs. I had to buy two sets to get enough of the 35mm plugs.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

However, I just took a look and that Sealed Power number is no longer available on RA, and actually has a very low web presence anywhere. I still have the bag un-opened somewhere and I will snap a pic or two when I find it, but it could take a while.

It would probably just be easier (albiet more expensive) to buy more than one kit of the other more easily available kits. You'll have plugs left over from buying multiple kits, but at least you'll have plugs.

Edited by Captain Obvious
The F54 block takes NINE 35mm plugs, not eight.
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I just popped for some dorman plugs from oreily's. Heck I almost think I could just open up the old ones a bit with a socket and reuse them... 

but I will stick with the China made dormans. I checked the OD and they are just a few thou larger, makes sense. Gonna leave the big on in back in place, it looks perfect. will check the fit of the one in front (got a dorman for that too) before I pull it, since pulling will def ruin it. I just get this feeling there is some hard to clean out junk behind it. 

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Be very careful dealing with the front plug. There isn't a lot of room behind it and if you just try to pivot it in place by knocking one side inward, there isn't enough room to swing it to get a grip on the other edge. So because of that, sometimes people drill through them and run a screw or something into them to act as a handle. HOWEVER.

More than one person I know has damaged blocks by drilling through that front freeze plug and kept on drilling into the cylinder jacket. Don't do that.

I drilled through mine (very carefully paying special attention to when the drill broke through the other side) and then I tapped the hole and used a piece of threaded rod attached to my slide hammer to yank the plug out.

Looked like this:

P1160313.JPG

P1160315.JPG

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