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shamefully joined the club of not securing the timing chain jam tool, despite being warned by my buddy Jeff.

So hours later after removing the timing chain cover its nearly all back together.

I was careful to mark orientation of dizzy drive. just have to reinstall oil pump, water pump, damper, torque head, reinstall the cam gear (more carefully with tool now, which by the way a home made wood one is better IMH, the plastic thing does not fit well and is prone to slipping).

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2 hours ago, Dave WM said:

shamefully joined the club of not securing the timing chain jam tool, despite being warned by my buddy Jeff.

So hours later after removing the timing chain cover its nearly all back together.

I was careful to mark orientation of dizzy drive. just have to reinstall oil pump, water pump, damper, torque head, reinstall the cam gear (more carefully with tool now, which by the way a home made wood one is better IMH, the plastic thing does not fit well and is prone to slipping).

Yeah, I did the same thing. Was really frustrating to have to dig in further for a silly mistake

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Its all back together now, just have to find my gasket making material to replace the oil spray bar gasket (one of them failed when removed it cracked off). Manifolds back on, everything hooked up but the radiator. New crank front main seal sine the old one looked like crap. I did NOT bother to replace all the timing cover gaskets. It came off pretty clean, and frankly I just want to see if the test kit still shows exhaust gas in the rad. I can handle some oil leaks. I did replace the water pump gasket since it cracked in have on removal. I did the FSM 3 stage torque setup. The head is still filthy as seen on the video, but the bottom sealing surface looked very good. I will prob be able to fire it off something this weekend. Have to do some other stuff so the engine does not take ALL my spare time.

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ok no change at all, Still fails exhaust gas in radiator chemical test. Still pukes up water until the thermostat opens ( a lot of water, like 1/2 gallon). Exactly the same as before the head gasket, which is really no surprise since the head gasket looked fine. Guess I should be happy that I did not harm and have now done a head gasket pull. Engine still gets hotter than I think it should with extended idling (guess about 10 min it will get to 180ish even with a 160 T stat and a 3 row alum rad). I figure that has to be something in the head I am missing (or the block I suppose).

I still have the maxima head and another head gasket on the way. I think will put on the maxima head just to see if the same results happen. Its going to up the compression due to the less volume in the head, but I figure it will just be a test to see if I can confirm this darn problem is a head issue or not.

Before I do that I am going to make a proper timing chain holder tool. I realize now I had the wrong tool, It was smaller than what I should have gotten based on pics and now a PDF diagrame of the correct tool.

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done for now, tried my 75 car engine, it warms up without any water puking, and passes the chem test perfectly. will post again once I get the maxima head on. I retested the spare engine compression test again, 165-170 across all. I also tried pumping up the rad to about 15 psi and then bore scoping the cylinders with a warm engine, could not see any obvious water leaking in. oh well its a mystery for another day.

 

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Cylinder pressure pushing gases into the coolant channels would be much higher than coolant pressure the other way.  Plus gases are less viscous than water.  Interesting problem.  Good to have two engines to compare.

Here's a thread with some chopped up heads that might show you where a crack or erosion could cause problems.

https://forums.hybridz.org/topic/59029-head-cooling-on-cylinder-5-solutions/page/2/

 

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I was thinking of trying to disable one cylinder at a time (disconnect FI plug) just as the eruption of water starts to happen (it last for maybe 10-15  seconds) After that the thermostat must open and no more issue (other than the orig problem). If just one cylinder is a problem, I figure no combustion no pressure, stops the eruption of water out of the rad, the water that comes out is not hot at all.

Kind of moot though, I want to see if the maxima head solves the issue, then I will know for sure.

Ok after sleeping on it, the plan is to start one cylinder at a time, remove plug, attach spark lead so spark has someplace to go, disconnect the FI plug. This way there is no compression, no spark, no fuel just a air pump. Then start engine on 5 cylinders and see if the water temp come up without the gusher. Do this on each cylinder away starting cold since I want the T stat to be closed for the test (the gusher does not happen without the T stat inplace).

Hopefully I can at least isolate the problem to a specific cylinder. What I do with that knowledge who knows but still I like to experiment so give me something to do. I can pickup a new head gasket and install the MN47 Tomorrow if I have the motivation for that. I am getting pretty good at removing and installing manifolds now, and since I just installed the head, I don't see any complications on the removal. I suppose I should plane on some 93 octane fuel, but for idle no load testing I assume I will be ok.

Edited by Dave WM

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after some more reading it seems this is a popular combo (N42 block/MN47 head), as my spare engine has dished pistons, perhaps the CR will not be as big an issue as I thought.

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Test one

left spark plug in, just pulled FI plug #6

started (miss obviously) let it warm up, NO GUSHER, water temp when T stat opened about 165ish per meat thermos on rad neck.

after letting run for a while like this I do the blue chem leak test (pull air from rad thru sieve into blue chemical look for change in color. NO change stayed deep blue.

finally hooked #6 FI plug back on while running engine speed picks up adj idle back down, NO GUSHER but then that was expected since the water was moving freely, but it did FAIL the chem test (could see it change from blue to green, would have been yellow eventually.

So sure looks like I have an issue with #6. Since the ONLY change from gusher to NO gusher was pulling #6 FI plug I will test results one more time, only change will be putting #6 FI plug back on and restart cold engine, if GUSHER then I would say that proves it beyond a doubt.

after that I will pull the head and look under a magnifying glass to see if I can locate any cracks. IF not I guess it could be a block issue, which would be bad since I have the spare head but not a spare block. I will reinstall the new head anyway since I don't know how to test the block. If new head has issues and #6 is the fault, then that would tend to make me think its a block issue since it would seem unlikely that both heads would have the same issue in  the same cylinder.

 

Edited by Dave WM

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got the replacement head super cleaned up, checked for warps again. One other thought, when I get ready to pull the old head off, I am going to rotate the crank 180 degrees off TDC. Then install the jam tool. I figure this will let me inspect the cylinder bore for possible cracks since that has not yet been ruled out (#6 piston will be at the bottom). I am 99% sure its #6 (either the head or the block) based on the test above so I can concentrate on inspection there. I was even thinking of some UV dye in the water and running it one more time, that way I can use the dye to help look for defects. Will run with the cap on so some pressure is built up after shut down. Granted the pressure will not be the same and in the reverse direction, but I figure it cant hurt.

Clearly I will have to remember to set the cam gear off 45 degrees as well, will use a grease pencil to mark the chain and gear.

Edited by Dave WM

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That's some good diagnostic work there.  Magnaflux is the typical crack test method, I believe.  Looks like they've expanded their methods.  Might give you some ideas.

https://www.magnaflux.com/Magnaflux

I wonder how your engine would have run as a daily driver?  Pretty sure I've sen threads about gushing coolant and much discussion about "burping" the engines.  Maybe they just had cracked heads.  Ouch.

 

 

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8 hours ago, Zed Head said:

Magnaflux is the typical crack test method, I believe.  Looks like they've expanded their methods.

Magnaflux, the company, has attracted competitors over the years.  If you go this route, you (or your machine shop) may decide to use someone else's product.  There are two generic methods available.  One (UV-illuminated dye penetrant) is suitable for an aluminum part like your cylinder head.  The other (magnetization of the part) only works with parts made of ferrous materials (steel, cast iron, etc.).

Although I have no direct experience, I would hazard a guess that the dye penetrant check might deliver the best results if you pre-heat the head in an oven before spraying on the dye.  Not flaming hot, but maybe 250 degrees F.  Read the instructions that come with the kit first, though, to make sure whether this is a good idea or not.

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well test today was not what I expected. started about 90f (ambient) engine started fine, #6 connected, NO gusher. This is the 1st time for that with a T stat installed. Now I am really confused.

there was  no water flowing (had the rad cap off with the meat thermo reading water temps (Plus I just put my palm up to the top of the rad). I was about 1 inch down from the bottom of the filler neck (about 1/2 inch of water covering the core estimated). Let it run fully expecting to see the gusher before the T stat opened. I stay quiet until the T stat opened right at 160f water begins to flow and stays there for a while, after about 5-10 min of idling it rose to about 175 on the T stat and held there. Water flowing everything normal.

Block test a few pumps, no change then had to break the vacuum by pulling it out and try again. It eventually did a very slight color change but seemed like I had to not have a tight seal least it suck itself down too hard to pump.

Bottom line is I am going to give it a rest, try again next week. If it does not gusher again I will have to ponder exactly what's going on. I guess I could have been a air pocket, but that does not explain the slight change in fluid color. I have the other head prepped and ready to go, so will prob swap it anyway now that I have read up on the swap being a nice performance mod. I still think I have a bit of a mystery on my hands.

I suppose the best course of action would be to simply take it  to a machine shop that can test for cracks in both the block and head and then get it machined as required (if ok). But at this point in time it seems that would be a waste of money since I really don't have an immediate need, and I really just wanted a spare. I too would like to see the engine in actual use ZH that would be a real world test since the only issue right now seems to be the chem test  fail.

 

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next week I will do a full video of a cold start thru chem test so you guys can see what's going on (same test I did today), as I would like any observation on what I am doing and if doing something wrong. Might get a little boring waiting for things to heat up (why I did not do today, just figured it would gush and I would then go right to the head replacement and block inspection).

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Maybe you had residual combustion byproducts in the block.  Or maybe you just have a small leak that shows on the test, but is not the cause of the gushing.  You're trying to assign two separate results to the same cause.  Might not be the case.

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yes I see your point, could have been an air pocket super heating the water before the T stat opens (Gushing), AND a very small leak causing the chem test fail. Perhaps I finally got the air out (no gush) but still the leak enough to fail the chem test. Oh well will test again (I like repeatable results to test a theory) if the gushing is resolved but continues to fail test, perhaps the  working theory will be just a very small leak. I did NOT retorque the head bolts (felpro gasket) as that was the instructions.

 

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series of test to be video recorded

  1. cold engine, rad cap off, start monitor water temp with meat themo, check for gusher
  2. engine warmed up and running check for exhaust gas in coolant
  3. cold engine, rad cap off, #6 disconnected start monitor water temp with meat themo, check for gusher
  4. engine warmed up and running check for exhaust gas in coolant

 

 

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test completed, no gush, some gas, video to be posted later, but I wanted to show Jeff his gauge, I did not do a before shot, but it came out pretty nice. Must be earlier on, has the 140psi oil gauge

 

107_1601.JPG

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did test 3&4 (disabled #6, cold start) exact same, still changing color. I am not going to bother trying it out on each cylinder, so will just move on to replace head. If that does not fix it I will pull the head and front cover so I can turn the crank and  CAREFULLY examine the block on all cylinders.

As a test I did pull air thru the fluid engine off rad cold, no change. Just wanted to me sure the chem could stay blue when being aeriated.

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Dave keep the gauge. Looks great!

You could always go grab the n47 block from the maxima. You got most of the work done already and we’ve been rain free for weeks now. 

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I grabbed that a while ago, installed it today, new head gasket, all buttoned up but I was to wasted from working in the heat that I decided to wait till next week to fire it up. I did adjust the valves and made sure my pump was still working (so the fuel pump relay and all the wiring was still hooked up.

I used my cherry picker to help with removing not only the head but the manifolds as well (did I mention it was hot today? prob feels like temp in the low 100's true air temp was in the upper 90's).

The cherry picker is proving its worth. I also made a wood timing chain jam tool, worked great! cold compression was about 165 on all but #6 which was about 155. I did not notice any thing valve issues on that one, but will check again after running it some.

If this does not fix it I will just tear down the motor an take it to a machine shop for evaluation of the block and heads, use which ever one looks better. I would like to do a full engine build anyway.

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