engine rebuild

[Gordon]

Thats cool, just tryin' to help. These engine are very resiliant, as you can see by the condition yours is in.

 

[inxs]

- pretty clean looking...that valve looks a little suspect but may just be depositing-wont really know without removing them-mark or bag them so you know which cylinder they came from, lap them in, cleanup, decoke, new gasket, some say to put a dab of sealer around the camchain well and studs-i never have and have only had leaking when ive forgotten to retorque the head and then recheck again later

- when lapping the valves you should see a clean ring of about 1.3mm in the middle of the seat

 

[breahn riley]

What's the trick to compressing the valve spring? I don't have the "valve spring compression tool".

 

[xsjohn]

Buy one or maybe rent one at Autozone..........or a big c-clamp (which I use) with a hollowed out 1 1/2" piece of handlebar hollowed out to get so you can get to the keepers......other ways out there for sure......

xsjohn

 

[Gordon]

Breahn, the best way is to get the one from Mikes, with all the attachments. But, as John said, a large 'C' clamp with a piece of round stock the size of the valve cap with some openings in it to gain access to the 2 little keepers with a magnet. About a 6" clamp should do.
I got the one I told you about from Mikes. For me, it works out well because it's big enough to get into the small 4 cylinder engines, as I get allot of 'kids' who bend valves because of improper timing belt change's. It is cheap enough ($ ) to own. But of course, you want it done ASAP. The one from Auto Zone might not work, unless you get one that will do Dodge Neon 4 valve heads.

 

[breahn riley]

C clamp and a 19mm socket did the trick. Wire wheeled the head and valves, cleaned up pretty well. Ill post pics tmmrw. Inxs, ill need some more info on those terms. Decoking, valve lapping

 

[Gordon]

De-coking is the removal of the carbon. Just another word for it. Valve lapping is cleaning up the valves, seats, & using valve grinding paste on the face of the valve, where it contacks the seat, and rubbing the valve back & forth to 'see' where the valve does the actual closing. There are allot of reasons for doing it, first is to see where the valve & seat come together. Next is to see if there is enough of a surface of contact to effectively seal the valve. Third is to make sure that the valve ismaking contact to the seat all the way around, usually all three are checked at the same time. The valve should make a contact seal about the width of a dime. Some guys use lapping sticks, others use a hose on the stem & rub that between their hands back & forth, I use a slow speed drill, first one way, then reverse. I am constantly 'lifting the vaalve off the face so I don't get allot of heat build up or wear a ridge into the seat or valve.

 

[weekendrider]

While you are in there you may consider cleaning up the rough casting in the exhaust ports.

 

[breahn riley]

How do you clean that? There is a ton of debris looking metal, just the casting on the intake side too. Kinda just really bumpy and rough.

 

[Sundie]

dremel with a flapper. You're not looking to eat too much into the runner, just to smooth it out. Like one of these.

 

[inxs]

- you really want a die grinder and some long shank carbide die grinder bits and polishing heads
...long shank bits or long reach burrs

...die grinder

...polishers

 

[Sundie]

IMHO, i'd only use the carbide bits if you wanted to reform the runners. They'll bite into the aluminum quite quickly if you're not paying really close attention. Newb's should stick to flapper wheels for simple casting removal, but again - just my opinion.

 

[inxs]

- a good point sundie, the bits are good for things like valve guide housing reshaping
- in fact the secret to XS porting is not how much you take out, more how well you smooth the flow contact zones

 

[Sundie]

Yep. the idea is to get a smooth flow, and a "sheen" to the metal. The raw casting leaves bumps, which at high flow rates creates a layer of turbulence as much as 1/8 -> 1/4 inch. The essentially reduces the nice large plenums drastically.

When i cleaned mine out, i actually had to go to a larger main jet, because i was starting to lean out huge at +5k, where before i ran slightly rich up to 7200. That's with stock airboxes, 38's, and slightly freer flowing commando pipes from Mike's.

 

[breahn riley]

Here are some photos of the head and valves all cleaned up. None of the valves are bent. I didnt check them with a square but i did roll them along a flat surface and no ups and downs. Sundie, when you grind the ports are you pulling the valve guides? next thing is to clean up the ports and time to reassemble. I am not looking forward to putting the collets back in. what a pain to get them out i can only imagine what a pain it is to get them back in. Im excited to hear about the improved air flow. I would love to see the motor making more power than before.

 

[Sundie]

It's easier (and more complete) if you pull the valve guides, but you don't have to. try to not hit them with the flapper wheel. You'll have to use a brass manual brush and some elbow grease to clean around the guides.

I've found a brass round drill brush like this

is fabulous for cleaning the crap out on the first pass. You basically stick it inside the runner, and run the drill up to speed. The faster you run the drill, the more pressure it will clean the insides with as it spreads out. Slower for lighter pressure. Then go at it with the flapper wheel to smooth out the castings. Then you can go in with the brush again to smooth out the flapper wheel marks. the idea is to get a nice smooth airflow going on, with no kinks or bumps. You can also use the brush on the drill to clean the combustion chambers/valve seats before lapping. the brass won't cut into the steel at all. I have pics of mine around here somewhere... I'll see if i can't upload.

 

[Sundie]

Here's a before (just having taken the head off) and after wire brushing, but before flappering. Which i don't seem to have pics of. But those ridges you see in the after pic are gone now, giving a nice smooth flow. I didn't get entirely to mirror finish, but that would have been a little more OCD than i usually am.

Also, the before is a nice view of "how to know when your headgasket has failed.

 

[breahn riley]

so you clean out the inside of the valve guide? id be worried about removing too much material and creating slop in the guide. howd you get the collets back in? do you have a valve compression tool?

 

[Sundie]

no, i didn't touch the inside of the valve guide at all. And you shouldn't.

And you shouldn't clean the section of the valve that sits in the guide either - any kind of abrasive cleaning will screw with the tolerances. Basically, where it's carboned up, clean that, but don't touch any other part of it.

Yeah, i've got the valve compressor from Mike's. Does a fine job. I also picked up a set of dowel stands from Princess Auto for $10 - made things a lot easier with the head level and elevated while i was compressing the valves, and trying to fit the keepers in. And yeah, they're a bit of a pain in the ass until you get the trick of them. Basically, i compress the spring until i can just fit one side in, then try the other one. I might have to go another turn before it will drop in, then release the tension, watching them (hopefully) pop into place. I've found that if you compress too far, they tend to slide down too far, and yuo have to magnet them back out again to try again. Then tap the stem tip of the valve a couple of times with a plastic faced hammer to make sure they're seated.

One other thing: your outer springs are variable rate - ie: the coils that are closer should be on the bottom against the head. I almost always forget until i look at the head and realize i've put one in upside down.

 

[breahn riley]

gotcha about the springs. i did wire wheel the carbon off the stem side of the valves. youre saying that i shouldnt have cleaned that?