Black & Green modding thread (1998 Civic DX Coupe base) - Page 37 - Fuel Economy, Hypermiling, EcoModding News and Forum

California98Civic · 05-02-2018, 10:22 PM

Quote:

Originally Posted by freebeard

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Oil pressure/temperature? Where do the wires go?

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Seems it is one of two ECT components, either the sensor or the sending unit. I found it in the FSM just now. I guess the sensor aince it is implanted in the head, built to sustain heat, and sealed at the threads for pressure to resist presurized coolant leaks (I guess).

deluxx · 05-03-2018, 01:06 AM

I love what you have done to this car. A real inspiration. Keep it up my dude!

California98Civic · 05-03-2018, 10:17 PM

Lol. Could not find my 12mm crowfoot socket, called around to three stores for one, set up an appointment with a snap on guy to buy one from hime tomorrow, then went out for one last examination before sunset... the ECT unplugs (easily). Here it is, being unplugged for the camera.

Also got the intake manifold separated and the cam pulley removed and suspended, which means tomorrow is camshaft removal attempt and then removing the head itself to take it to the machinist.

19bonestock88 · 05-03-2018, 10:55 PM

Looking good so far! If you have a Dremel you could port the intake manifold while the head is being machined... not sure if it would help your build though

California98Civic · 05-04-2018, 08:15 PM

Quote:

Originally Posted by 19bonestock88

Looking good so far! If you have a Dremel you could port the intake manifold while the head is being machined... not sure if it would help your build though

I'm just gonna clean them. Got verything apart today. The head is with a very good engine rebuilder here. Getting a pressure test and resurface.

Here is the head gasket, which was installed in Ohio at Honda's Ana Engine plant in January 1998. It ain't pretty anymore:

What you see is the top of the gasket, with #1 on the right. The black is the sealant material on the gasket. As you can see, much is gone & compromised. Oil was getting into coolant, combustion gas was in the radiator, and burning coolant produced a little white smoke out the tail pipe. But there was no coolant in the oil. I can see that story looking at this. The two oil inlet ports are bottom right and bottom left. Two oil return passages are at the top, rectangular in shape. Gasket material is atill good all around there.

Tops of the pistons are caked with black tar:

Valves are black. And exhaust valves on one, two, and three are also coated with burnt gray carbon that cakes off in brittle chunks.

Gonna clean everything thoroughly and check the cam and do the cam seal too. Then valve lash adjustments.

I got 260,000 miles and 20 years out of this gasket. Solid.

California98Civic · 05-05-2018, 02:55 PM

With my head at the machinist through the weekend, I am working on two or three ecomods. Reinstalling a slightly rebuilt set of wheel skirts, removing and modestly redesigning the side skirts, and most importantly trying to learn if there is a way to do a "fuel economy" or low emmisions valve lash adjustment when I put the head back on and must adjust the valves.

I think tighter lash on both the exhaust and intake will produce longer, earlier, and later openings of the valves and increase overlap. What do you think? A reduced gap between the rocker and the valve stem means longer duration of the opening, with earlier opening and later closing, I think. Overlap is good for scavenging.

freebeard · 05-05-2018, 07:40 PM

I don't know if you can extrapolate from aircooled tech, but VWs (solid lifters) work best with .004" cold, but for the American market they recommended .004" intake and .006" exhaust, and then eventually .006" all around. Because Americans couldn't be trusted to check their valves every 1500 miles. It was a small performance hit.

California98Civic · 05-05-2018, 08:49 PM

Quote:

Originally Posted by freebeard

I don't know if you can extrapolate from aircooled tech, but VWs (solid lifters) work best with .004" cold, but for the American market they recommended .004" intake and .006" exhaust, and then eventually .006" all around. Because Americans couldn't be trusted to check their valves every 1500 miles. It was a small performance hit.

Interesting. Spec on this 1998 Civic DX is 0.007-0.009" on the intake and 0.009-0.011 on the exhaust. I figure that setting to 0.007 intake and 0.009 exhaust is a modest "mod". I don't think I need to fear too much change and wear all that quickly. For the first 200,000 miles the valves went unchecked and they were almost all (except #1 cylinder) in spec still. And #1 was only slightly tight (at 0.006 on one intake lifter, for example). Tightening should help emissions, too. I go in for smog testing later this summer.

freebeard · 05-05-2018, 10:45 PM

It isn't just wear. Less time on the valve seat means less heat transfer. VWs were notorious for the #3 exhaust valve being the most vulnerable.

If you stay in spec that should be sufficient.

California98Civic · 05-05-2018, 10:54 PM

Quote:

Originally Posted by freebeard

... Less time on the valve seat means less heat transfer. ...

That's an interesting point. Tighter lash = less heat transfer. It makes sense. The exhaust port must be the hottest place in the entire car. So less time for the valve to sit there also maybe means marginally less transfer to valve seals, too. And maybe slightly more heat sent to the CAT, sooner.