Wet L18!

[itsabby!]

I'm trying to resurrect my fallen L18, Due to water entering  the engine and mixing with the oil... in other terms making a chocolate milk shake..

i don't want it to be the end of the road for this engine and i don't have the money to get another engine so i have to work with i got...

I've done some reaserch here and what they say there are two main areas which are the head and the timing chain cover...

 

So this weekend i removed the head and this is what i found.......

 

 

 

 

it looks like it was a blown head gasket and the the water was coming in threw cylinders 2 and 3... (but im not ruling out the timing chain  cover senrio just yet)

the head doesnt look that good either besides the small surface rust it looks like the valves are burnt... or why else would they look kinda white

I've read that these heads arent notorious for being cracked but is my head Saveable or am i going to have to get a different head??? i was planning to take it to a machine shop to get it cleaned , resurfaced , a pressure test.

 

also is there any way to clean the engine out from all that milkshake? i see that prep is always essential...

I've drained drained the engine and also took the radiator out and ran the hose threw it...

 

Feel free to ask questions and for more Oics... need all the help i can get.

 

-Abigael

[Ratwagon1600]

Yuk!

 

I've flushed blocks previously using diesel fuel and straight petrol (gasoline).

 

Problem with issues like this is no matter how much you try and flush the block (whilst its assembled) your going to end up with oil/water in oil galleries, oil pump, bearing contact surfaces, piston ring lands etc etc.

 

IMLTHO the only real way to make sure the engine is clean is a complete tear down and rebuild (not cost effective I understand).

 

Another Ratsun option is to do as above (flush engine with petrol) and then put some cheap oil in, crank the engine for a minute without starting it (take the coil lead off), drain oil, repeat, and then put good quality oil in and cross fingers.

 

As far as the head goes, similar to the block. The valve discoloration is typical of a nice oil/water mix.

 

Again, your best option here is to tear down the head and rebuild it. Regardless of how hot the engine got, the minimum I'd be doing here is getting the head resurfaced, pulling the valves out and relapping them and replace the valve stem seals.

 

Or, you could change the oil and filter, boltit back together and it may (most likely may not) run like a charm!

 

Last option (again cost dependent) is a replacement engine.

 

What ever you end up doing, hope it goes well.

 

Fire away if you have any other questions.

[izzo]

You can clearly see the head gasket is shit between 2 & three.  Goodness. Get your compressor out and blow out the cylinders and dry it out. 

[Ratwagon1600]

I didn't want to state the obvious, but, Izzos right, I'd be 99.999999999% sure the head gasket failed between two and three.

[izzo]

^^^ lewwwwwwwwlz.   While the head is off, take it to a shop and see if they can test it for you. Check for flatness. make sure its still good between the two cylinders.  Can they test it off the block for a leak down/air??  Never had one checked, so I don't know if they can. But I would. Cheap insurance if so.

[Ratwagon1600]

Can they test it off the block for a leak down/air?? .

No. Your standard leak down test is done with engine assembled.

 

Best off engine leak test you could do here is make sure valves are closed in the combustion chambers and pour a bit of petrol in there and see if it seeps through.

 

From 25+ years experience of building these motors, I'd be sticking with my suggestion as I posted above, but, each to their own.

[izzo]

^^ Ah yeah thats right!  My brother is a mechanic, and that's what he suggested before. Now I remember.  I'd rebuild the head too or put on a known good one...  Think it caused any damage to his cylinders? I'd imagine not. I've had some with actual crusted rust... Used an emry cloth across it, put it together and it ran fine. 

[banzai510(hainz)]

I would swap a head gaskets and try it again. oil down the cylinders

ck the oil if water in there.

if the front cover is bad you got to remove the water oump and ck the back of the timming cover where the water pump was. Old antifreeze will let the front cover cavitate. Cause a tiny hole and let water in the oil. or water passage to block gaket is not sealed.

 

 

another thing is make sure you got the washers that hold the header and intake together.So its a flush fit as loose bolts will let water get sucked in there the gasket.

 

 

hopefully you marked the chain so you know what tooth to line up on the sprocket.

 

[datzenmike]

Wire brush the head and use a straight edge to check for flatness. Don't turn the cam.

 

Clean the top block surface the same as for any gasket change. Clean the bolt hole threads out too.

 

Drain the oil from the block, let sit overnight to get the most out. Put back together and fill with a gallon of oil and a new filter. When filling the oil pour over the cam, valve train and timing chain.

 

Fire up and run it till warmed up. Drain hot and change the oil and filter. Check later, if oil remains clear leave it. When it gets dirty (probably at the next change interval but sooner is ok too) change it again with a filter. Engine warmth will also 'boil off' any traces of water over time, so run it as long as possible when running it.

 

Water and oil don't mix and given time most of it will sink to the bottom and be the first to drain out. Any left in the galleries will be flushed with and diluted with a gallon of fresh. Two gallons actually. Water isn't the problem... it's water left in there for weeks on end. The sooner it's rinsed out the better. The cylinders are rusty from air and water. Crank bearings are more sealed and covered in oil unlike the cylinders.

[Sealik]

^^^ lewwwwwwwwlz.   While the head is off, take it to a shop and see if they can test it for you. Check for flatness. make sure its still good between the two cylinders.  Can they test it off the block for a leak down/air??  Never had one checked, so I don't know if they can. But I would. Cheap insurance if so.

 No....but they could magnaflux the block.....but

I would just clean the block/head etc. up as best as possible, and if no issues prior to the HG blowing, I would slap it back together.

Buy some cheap oil....couple of oil filters....change both again after you have it running.

 

.....Good time to take the head in and have it looked at though.....

[racerx]

you may want to buy this: http://www.amazon.com/Alltrade-648831-Nissan-Timing-Holding/dp/B0002Q8TV4/ref=sr_1_2?ie=UTF8&qid=1366067366&sr=8-2&keywords=L+series+timing+chain

 

You can make one but don't know dimension..also go on youtube and watch Hainz video on L series head gasket..it should come up or unless someone here can chime in and direct him. Yeh, that sucks but good luck.  Plenty of help here.

[itsabby!]

 

Again, your best option here is to tear down the head and rebuild it. Regardless of how hot the engine got, the minimum I'd be doing here is getting the head resurfaced, pulling the valves out and relapping them and replace the valve stem seals.

You say getting the head resurfaced is the minimum work on it, what would a complete rebuilt  head consist of???

 

hopefully you marked the chain so you know what tooth to line up on the sprocket.

 

awwwwwwww shucks! i was too focused on getting it top dead center! 

but yeah your video helped me alot!

 

Wire brush the head and use a straight edge to check for flatness. Don't turn the cam.

wouldn't a wire brush damage the head by carving into it???

i've heard the're aluminum and steel wool will be better off.....

 

you may want to buy this: http://www.amazon.com/Alltrade-648831-Nissan-Timing-Holding/dp/B0002Q8TV4/ref=sr_1_2?ie=UTF8&qid=1366067366&sr=8-2&keywords=L+series+timing+chain

Dont worry man i got it! cant really see it in the picture but yeah its there! :thumbup:

[Ratwagon1600]

The definition of a "rebuilt head" will vary from shop to shop, and how much money they think they can bleed out of you.

 

Down here, if I was purchasing a rebuilt head, this is the minimum I would expect:

 

- 3 angle valve seat cut and valves recut/refaced

 

- new valve guides and valve stem seals

 

- head to block surface refaced, and

 

- head hot tanked

 

As I said above, it really depends on the shop. Some might try and talk you into new cam, lash pads, springs, valves, porting etc etc.

 

Unless you are building a go fast motor, these additional bits are generally unnecessary.

 

If nothing else, at a bare minimum you should get the head refaced and the valves lapped so they seal properly.

 

When the valves are out it is a quick job to replace the stem seals so I would suggest doing this at the same time.

 

As far as Mikes suggestion with the wire brush, um, it's a bit Ratsun but as long as you are gentle, you shouldn't damage the cylinder head face. Despite being Aluminium, they are fairly resilient, just don't go using a scraper blade or anything with a sharp edge and you should be right. Steel wool and some WD40 is an alternative if your not confident about the wire brush idea.

 

Another Ratsun method which I've used in the past to reface a cylinder head (note this is an uber tightarsed option) is to get a clean piece of sheet glass and some fine lapping paste, coat the face of cylinder head with lapping paste and then gently rub it on the glass using figure of eight circles. Sounds crazy I know, but, it works to a degree. Of course you need to have said piece of sheet glass handy to do this. If you ever try this and you don't have a spare piece of glass, I find using the neighbors windows a much more preferable option :)

[Xnke]

In order to work on the head, you'll have to strip it bare or have it done. Don't be afraid of removing the cam towers, there is no voodoo magic there, no matter what some here will have you believe.

 

If it was my engine, I'd wipe the bores down with an oily rag as quick as possible, send the head to the machine shop and at a minimum:

 

Head would be completely stripped and checked for flatness, valves would be replaced (reusing old valves is false economy, they're 6$ each new.) valve guides would be replaced, seats cut with a 3 angle job.

 

If the head is more than 0.002" out of flat (I think the FSM states 0.003 is the maximum allowable) it would get decked both on the headgasket side AND THE CAM TOWER SIDE! If you warp the head by overheating, and then only cut the bottom surface...now the surface that the cam towers sit on is NOT FLAT! If that surface isn't flat, then the cam binds up. It might still "work" but it won't be right and best case, it saps some power to drive the cam in a bind, worst case it breaks the cam at speed.

 

If the head is really warped, then you need to get it straightened and then decked top and bottom. A machine shop familiar with the datsun heads can do this...and if you're really good you can straighten them to the point that 0.001 or 0.002" is all that has to come off. I've personally done it once, but that was blind luck. The machine shop I use for valve jobs on my ported heads routinely straightens aluminum OHC heads all the time.

[Sealik]

One could just 'check' the head to see if it's warped by rotating the cam with the rockers removed???

If it spins freely without bind......should be somewhat of a go??

Other than any other issues with seats....valves....etc.... of course

 

My E31 blew the HG.....removed head....cam binds on rotation

 

6 bucks a pop for valves.........hmmmm....I wish.... :D

All relative to locale I guess....paid about 20 each

 

You are correct on the removal of the cam towers....done it many times, no issues.

Just make sure everything is clean....torque to 5/10/12 lbs

[itsabby!]

Why walk to your neighbors house? When you have your wife's patio table at home!

 

<iframe width="560" height="315" src="http://www.youtube.com/embed/mc_gaGAf2pk" frameborder="0" allowfullscreen></iframe>

 

Seem like fun but i think im going to stick with the machine shop for now...

 

Thanks to all for the help and ill keep this tread updated through out this project...

[banzai510(hainz)]

I would just quick ck the head for straightness with a staright edge

 

slap another 12dollar Felpro gasket on there and run it. cost of oil filter and oil.

 

Unless you thinks you really warped the head that bad. but long as soem water was in the engine i dont think it would warp that bad.

 

key is was when you took the head off did the bolts give a snapping sound when you broke loose or bolt just came loose. and between 2 and 3 was a weak point.

 

rememebr the crush height is about 1.5mm which I think is .060 thou and bolt that sucker down to say 45pounds ands see what happens

[itsabby!]

 

key is was when you took the head off did the bolts give a snapping sound when you broke loose or bolt just came loose. and between 2 and 3 was a weak point.

 

Sorry havn't wrote back in a bit but unfortunately don't own a computer....

 

But all the bolts did snap when removing including the ones between 2 and 3, Is this a good sign? 

Am i really getting a break??? :w00t:

[motavated]

huh? I got some extra head bolts. Come pick them up if yours did break.

[datzenmike]

He means thay let out a snap when coming loose

[Xnke]

Yes, if you remove the head and the cam binds, you need to get the head straightened before milling.

 

If you remove the head but the cam does not bind, that does NOT mean the head is straight! Check it!

 

If the engine overheats even only one time...that is still enough to warp a head. Some guys get lucky and overheat it multiple times....others don't. There isn't a rhyme or reason to it...if it's been overheated, check for warpage.

 

The Fel-pro gasket is 0.040" thick at full crush. Check your head bolts for stretching or damage; don't reuse rusty headbolts, blah-blah-blah.

 

Check along the deck surface AND the manifold surface! I have an L28 head here that is banana-shaped on the manifold surface, but is only 0.0013 out on the deck and cam surfaces. The cam is also broken in this head...I keep it for a display to show customers who want a "cheap valve-grind-only" on a BHG change. Some still only want the valves lapped in and they'll run the (usually pretty warped) head under the guise of "the bolts will pull it back flat!" until the gasket blows again. Some "checked the deck and it's straight enough for me, the head should be good!" and they don't realize the head can warp in directions other than up and down.