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Posted by: PanelBilly Oct 14 2010, 10:53 AM

I started to break down the creamsickle engine this week. I pulled off the tin and FI to find the top of the cars and cylinders packed with oily dirt. What a mess. The thing smoked on deceleration and leaked oil. I figured I'd pull a head and I'll post some photos later. It all looks nasty oily. Where do I stop?

Any of you NW guys care to give me a hand?

Posted by: McMark Oct 14 2010, 11:10 AM

Quick and dirty 'rebuild' would be to pull the heads have have them rebuilt, and then hone the cylinders and rering the pistons. Obviously this won't be any sort of power upgrade, but it will put some more life back in your engine.

Posted by: Dr Evil Oct 14 2010, 11:22 AM

It also will not repair collapsed registers if you have them. Have the case registers checked to save yourself some headache.

Posted by: ldsgeek Oct 14 2010, 12:07 PM

Can the registers be checked at home? If so what equipment and how to do this?

Posted by: sean_v8_914 Oct 14 2010, 12:07 PM

wouldnt colapsed reg cause a head leak?
inspect the head to cylinder sealing surface on teh head and cylinder. it should be evenly marked where the cylinder rests
when you remove the heads remember to plug the lifter bores with paper towel wads so they dont fall out. gotta keep em in teh right hole.
inspect each cam lobe w a flashlight. if they are not chewed up looking and the lifter face looks ok, slap it back together like McMark said

I have found many engines assembled without consideration to deck height so if your deck hieght is .085, there might be a few free ponies there to unleash

post some pics. the collective will figure it out

Posted by: Jake Raby Oct 14 2010, 01:56 PM

Here is a classic example...
People who aren't decking cases are going to create themselves head leaks and issues.
This case was out .020 with sagging @ 3 and 9 O clock positions.


Attached image(s)

Posted by: Vacca Rabite Oct 14 2010, 03:23 PM

I had to deck my case .010

Register collapse was the root cause of a failry large head leak.

Of course, you can't check for it without splitting the entire engine.

I would do a leakdown test on the engine and see if it is excessive. If you have a leaky cylinder, its easy to find out where it is leaky. Pressurize the cylinder with the same attachment that you use to pressurize a cylinder for leakdown testing. Leave it pressurizing and start squirting the cylinder with soapy water ( I used windex) and look for bubbles.

If bubbles are coming from your valves, you know you need a valve job, but your case deck is probably fine. If the bubbles are coming from between the head and the cylinder joint I would strip the motor completely and have the case checked and decked.

Zach

Posted by: mojorisen914 Oct 14 2010, 03:25 PM

Pulling the engine apart, Where do I stop?

When you get to the end.

Posted by: Dr Evil Oct 14 2010, 03:32 PM

My first thought was "Depends on your wallet"

Zach has a good idea. However, IIRC, carbon buildup can mask some head leaks with this test.

Posted by: sean_v8_914 Oct 14 2010, 04:08 PM

why do you think they sag in the middle like that?

Posted by: Vacca Rabite Oct 14 2010, 04:13 PM

If it leaks during a leakdown test, it will leak with the bubble test.

if the carbon deposits masks the leak at the leakdown test, you will never take the bubble test. At least this is the case if you do the bubble test at the same PSI you did leak down at. I did it at 100psi.

Zach

Posted by: PanelBilly Oct 14 2010, 05:13 PM

colapsed registers, what's that?

Decking the case, I can figure that one out by the photos.

I've already pulled one of the heads off last night and it looks like there is blow-by between one of the cylinders and the head. I'll pull the other one off tonight and take pictures.

Posted by: McMark Oct 14 2010, 05:37 PM

The big question is do you want to build it 100% right and spend whatever it takes? Or just get back on the road? Nobody is giving you wrong information here. But it's easy to recommend a whole list of checks and upgrades when it's someone else's money.

Posted by: Vacca Rabite Oct 14 2010, 05:39 PM

a register is the hole in the case that the cylinder slides into. When it collapses it is warping a little in the center due to a lack of support there and lots of heat cycles in the case.

2.0 914 engines and engine that were in buses are especially prone to this. The bus engine just because the engines ran hot pushing a big brick down the road. The 914 engine due to the case being a little thinner in that location then the other T4 engine iterations.

Zach

Posted by: r_towle Oct 14 2010, 05:48 PM

Coming from you, a perfectionist, this is a joke question, right?

Take it all the way apart...
Start at the beginning, it will last another 100k.

Powdercoat the tin, fan, front fan housing, taco plate, sump cover, and all your tin screws.

RIch

Rich

Posted by: Jake Raby Oct 14 2010, 06:02 PM

Because the adjacent cylinder register takes material away from that area of the case.. and because of a lack of support behind that portion of the registers on the GA cases and newer..

W cases are the best in this regard.

As far as what to do with the engine.. Do it all the way, or not at all. A dollar saved now can equate to thousands spent later.

Posted by: sean_v8_914 Oct 14 2010, 09:39 PM

it is interesting to note that the GA case is the one people allways want because of the reputation of the 73 2.0. one could speculate it to be the most re-used/abused rode hard put away wet case.
all those early 1.7 cases got thown to the side and swapped out for rebuilt GA whores. so teh rebuild count on a per case would be lower. a 1.7 case with more of her virtue intact

Posted by: PanelBilly Oct 14 2010, 09:45 PM

This head didn't look so good to me



The block is just packed with oily dirt

Posted by: PanelBilly Oct 14 2010, 09:47 PM

This is what has me worried

Posted by: sean_v8_914 Oct 14 2010, 10:24 PM

thats a pig-rich oil burper.
those heads are damn near virgins. still have the casting boss around thr holes.
valves look a little deep
is that a crack on the left hole from plug to exh valve?

Posted by: silver74insocal Oct 14 2010, 10:28 PM

"thats a pig-rich oil burper"
can you dumb it down a notch for us non-technical people?

Posted by: sean_v8_914 Oct 15 2010, 08:27 AM

heavy black carbon deposits suggest too much fuel delivery
wet appearance may indicate that the oil control rings are not working
are the cylinder walls scored? can you feel the marks with your finger nail?

Posted by: sean_v8_914 Oct 15 2010, 08:30 AM

the raised ring on teh head that surrounds the piston hole gets shaved down after many rebuilds on the heads. these may have had 0-1 rebuild ever done

Posted by: HAM Inc Oct 16 2010, 08:09 AM

The heads will need at a minimum news seats, guides, valves, springs, and ex. studs and machine work. They will liekly need some welding too as the 2.0 914 with no cracks is a rarity.

Deck the case while you're at it. I've decked a LOT of T4 cases over the years and I have NEVER had one in the mill that didn't have at least one spigot that wasn't out enough to warrant the proceedure. Most have multiple sagging spigots.

Take your time and do the build right the first time. If money is an issue set it aside until you have the funds to do it right. You'll be glad you did. Some engines are a bit forgiving to cutting corners. The T4 isn't one of them.

Posted by: Jake Raby Oct 16 2010, 09:41 AM

GA cases are my least favorite.. I'll take a W, EA or Ec case over two GA cases.. I will state that the earliest GA cases do have the reinforced registers that I prefer.

Those chambers are contaminated with both fuel and oil deposits.. If the engine was running rich the ring seal could have been compromised by the fuel, because fuel is a solvent, not a lubricant.. This causes the rings to allow oil to bypass them and contaminate the chambers.

I see one piston that looks like it could have been tapping against the cylinder head, if thats the case you'll be finding a bad rod bearing very soon upon further teardown.

Engine looks typical at this point. These machines are approaching 40 years of service, the days of half ass rebuilds and corners being cut have been over for a long time.