So I've been going crazy tryn to figure out why Ive been burning oil. First I was thinking it was pulling from the PCV, next I was thing bad Intake gaskets. All of those where ok, finally found the issue after pulling the head that was fouling plugs...All my valve guides are wore loose. These heads only have like 1500 miles on them. They are Brodix 200IKs. My other head was not fouling plugs but I just pulled it today and ill have all the guides replaced. Any idea why this would happen???? mods in sig

 

I see this from time to time. I recall a pair of Dart Iron Eagle 180 heads, less than 2,500 miles on them, the bronze guides were very barrel shaped, I had to replace all 16.

 

any idea why? Just a bad batch of guides? Could this be caused by parts not matching, to much lift on the cam? Dont want to just replace the guides and have it happen again.

 

No, it's nothing to do with cam or rockers. That'd have the opposite effect on the shape of the guides.
Have your local shop mic the ID of the new guides, at both ends and in the middle, before installing them, unless they're going to do liners. Don't let them knurl!
I'm opposed to putting bronze liners inside bronze guides, but some shops have learned ways to make it work for them.

 

thanks for the advice. So this just sounds like a odd ball problem. Any idea what caused it to happen. I dont mind getting fixed just dont want it to happen again in another few thousand miles.

 

What kind of seals? Geometry correct?

 

you tell me, heres everything I know.

running a comp 280XFI cam .576/.571 230/236@50 280*/288*
Comp Roller Rockers 1:6
Comp Magnum pushrod 7.300(all)-12 say 1909,3 say 2509,1 says 2909
Brodix 200 ik heads milled .005
Comp retro fit lifters
Comp duel springs spring height 1.800 Tension Int. 140...
Open 380@ 1.200

 

Ironically, I just replaced a set of summit aluminum heads two weeks ago on mine because of the same issue. The summits are supposedly made by brodix. I was using way too much oil and fouling plugs. Last year, I reringed it because I felt there was no way new heads could have bad guides, but I was wrong.

 

I'd first suspect a valve train geometry problem, probably resulting from the incorrect pushrod length. Virtually all the valve train companies warn about accelerated valve guide wear when the incorrect length pushrod is used.

On other Forums, I often see posts where, rather than measure/check, a member will just use the same length pushrod that someone else is using. The thinking being that since they worked on his engine they'll work on mine. In fact, each engine should be checked individually.

Jake

 

Forgot to add this in my PM. Get them repaired and when you install them again, try to check for the proper pushrod length with a checker and perhaps order a solid lifter or a checking spring. Put in the check spring which is a low pressure spring used to check valve events and such, and try to get an idea on what the rocker tips are doing on the valve stems. Color the tips of the stem with magic marker and install rockers. rotate motor over a few revolutions to get a complete rocker arm travel. Then look at the markings.

For now you can just look at the markings on top of the valve stems and see what it looks like. Should have a thin line splitting the top of the stem in two even half circles, indicating the rocker tip is centered properly. If its got a fat line or the whole top of the stem has rocker tip travel marks, then you have incorrect pushrod length.

 

wrong-length pushrods can't cause barrel-shaped guides. You'd get the opposite result.

 

No but positive seal telfon seals will, they just wipe off too much oil for a street car

 

Yep, that's why they're a "seal of last resort".

Jake

 

If mine were like tpiformula's, it used oil from day one. Thats why I was so stumped like he was about why it used oil.

 

Interesting comment. What's your source on that?

Jake

 

not sure what type valve stem seals were used..They are blueish green in color and have a ban around them?? Thanks for the info guys..I'll def be checking the pushrods length and geometry with a gauge and try the magic marker trick to see where the rocker tip is landing. I spoke to brodix today and they said it could be a few things.
1. Valves put together dirty...they were not.
2.Ran the engine dry.....never ran low on oil
3. Geometry...... have to check that out.
4. Bad guides.... maybe
5. Heat......... I was having a tuning issue, pinging at higher RPMs and saw header glowing when it was dark out, I have since had fuell added and timing removed from tune.

 

I was going to mention excessive heat from wrong tune but didnt you have this setup tuned up at a dyno?

 

My source is my experience, but basic physics will suffice. Heck, draw it out for yourself and study that. I can't see how anyone could have any difficulty grasping anything this simple.

 

Heat can kill the guides, but I don't think it was from your choice of valve seals. The bluish-green with band are normally perfect for the intakes. For the exhausts, umbrella seals and o-rings tend to do best.

 

Most people destroy them while trying to install them. some then order a second set, but most give up on them and go back to the viton seals like they should.

 

yes, it was dyno tuned so figured i was all good,but it was pinging and me and the dyno guy took the car for a ride on the street and he adjusted the tune. This was like 2 months after the original dyno tune. didnt here pinging after he took out alittle timing and added fuel.

 

I spoke to my engine builder yesterday and he said he would be replacing the valve guides. He said they were way to loose to knurl them. I'm still not sure what caused this to happen. I wrote in an earlier post it may have been heat from a bad tune because I heard a pinging. I sent bin I was running while the car was pinging to Orr89RocZ..He looked it over and was thinking it was not to aggresive and ramped up to 34* total. So now I'm wondering if the pinging I was hearing had nothing to do with my tune. It was making a ping/cladder noise over 4200RPMs but sounded to be coming from the head with the bad guides. I had been getting a gold/bronze color in my oil changes .Is it possible the pinging was just because the valves were so loose in the guides??? Or maybe it was jjust the oil in the combusion chamber causing hot spots and making it ping??

 

What he said, since your stupid shop mentioned doing that.

As far as the guides, anyones guess at this point. Make sure the geometry is right, that the guides are within proper spec with your new ones installed, and hope for the best.

 

May not have been timing but overall air fuel. I dont expect your setup to be using THAT much fuel over what I ran, and your bin is somewhat similar to mine. I also dont expect it to use much less fuel. I dont think its too lean but when you said glowing headers at idle, makes me wonder what was going on in those chambers. Perhaps too rich with too little timing causing burn in the exhaust? Else too lean there with too little timing. 24 deg isnt all the low but that cam can go higher with the 383.

 

In other words, you don't have a source other than yourself. That answers my question.

Jake

 

What procedure did you use to determine the correct pushrod length? You did check for that,, right?

I know you don't want to go through all the trouble and expense of having all the guides replaced only to have the same thing recur.

Jake

 

I didnt build the engine it was build by a local engine builder. When i do put it back together I'll color the top of the valves with a marker and turn the engine over afew times and make sure the rocker tips are riding the center of the valve. This is the way ppl on here have been telling me to do it as well as the techs at comp cams.

 

Using the wrong length pushrod increases side loading on the valve, which increases the wear rate at the end of the valve stem, not in the middle.

 

Make sure the rocker tip sweeps the narrowest travel across the face of the valve. This won't necessarily be when the tip is in the center of the valve.