Well, not TODAY:

I pulled the rocker arms off of the #1 and #3 valves a few minutes ago. Found some interesting markings on the tips of the valves. #3 intake marking from the roller rocker is spot on; centered nice and even (top to bottom) across the width of the valve. #1 I/E and #3 E valves are another story. The markings are to the left/right of the center; as if the rocker arms are not staying centered on the valve tips and instead are spending more time to the left or right. However, they are right in the middle of the valve tip (top to bottom) as the #3 intake valve.

This leads me to suspect that my Manley raised guide plates that came stock on the heads when new from Indy Cylinder heads a decade ago are wrong for the DART Iron Eagle 180cc cylinder head.

The literature that came with the heads at time of purchase calls for Comp Cams #4808 FLAT guide plates. I assumed INDY knew what they were doing. At the time, I didn't know the valves are slightly moved left or right to aid in intake/exhaust flow. I learned a lot with this year's top end refresh.

When I had the heads rebuilt, the bronze guides were extremely worn and the hardened valve seats (all 16) required stainless steel inserts to be made whole again... and all after just 30k miles. I SUSPECT, these Manley guide plates are the wrong application. I would like to run raised guide plates and will check to see if the Comp 4808 has an alternative raised guide plate.

Anybody know?

Oh, and the #1 rocker stud holes, both I & E, do NOT go through into the cylinder head runners as I originally suspected. Will advise if #3 thru #8 do. The threads of the two rocker studs were wet with oil but the holes definitely bottom before entering into the intake/exhaust runners and the bottoms of both holes were dry.

For now, the engine won't be buttoned back up with these guideplates. Although the pushrods are correct length, the guideplates are positioning the rockers off-center from the valves. I've put about 750 miles on this build and am hopeful I've caught the wear in time. The valve tips are marked but not pitted and the roller tips are still smooth.

 

I ended up using some of these to rescue some garbage Summit-brand iron heads:

http://www.summitracing.com/parts/isk-200-agp/overview/

I wouldn't sweat anything from what you're seeing - there's probably some guide side-loading happening, but I wouldn't think anything worth worrying about.

Seems odd, though :-/

 

On the DART tech sheet for the 180cc iron eagle, the following DART pushrod guideplate is listed:

DART 27001110.

On Jegs, "Similar Items" cross-referenced against the DART 27001110 are:

Comp Cams 4808-8 - flat
Comp Cams 4800-8 - raised
Manley 42151-8 - raised <----- I have these today
Lunati 86516-8

I have read that having raised vs flat is a good idea to improve leverage and move it closer to the rocker arm pocket. I read the flat plates may be too far from rocker pocket and add risk of pushrod bind/bend.

Perhaps I am worrying about nothing? Perhaps I can proceed with sealing those threads and stop being a worry wart... ehhh?

45lbs is recommended rocker stud torque per DART

 

OK.

I've removed, cleaned, applied sealant and torqued all rocker studs on #'s 1, 3, 5 and 7 cylinders. Push rods were carefully kept paired with the rockers/lifters and rockers are finger-tight on the rocker studs now.

Not ONE rocker stud hole opens into the intake or exhaust runners; contrary to my belief.

Both right and left cylinder heads are identical. There is no sense in my removing #'s 2, 4, 6 and 8 cylinder rocker studs. The oil that is passing the threads isn't going anywhere.

That means I have to explore the possibility of another source for oil in the intake than the rocker stud holes:

1. PCV valve/hose to carb base. The PCV valve has probably never been replaced since I installed shortly after purchase. The pcv valve seems to work fine; it rattles when I shake it... what else should I check with PCV? Do they really go bad?
2. Rings. About 30k miles since 1999 rebuild but the C3 sat A LOT once I bought the '69 L46 in Spring 2005 until I sold the L46 in 2008 or '09.
3. Head or intake gaskets... sucking oil into intake/cylinders (a stretch... I torqued the heads and intake in proper order and torque... unless I have severe warping but I would suspect coolant loss to combustion also)

My last drive did not burn 1/4 quart of oil as I had suspected. Oil just took a while to all drain back into the pan. Not sure about amount of consumption but I AM getting blue smoke while the car idles in the garage. It is not a cloud of blue smoke but it is visible from inside the garage looking out at the street.

That wouldn't be a rich condition as I would expect black smoke and burning eyes... right?

 

Set the valve lash this morning and buttoned things up so wife and I could take a nice drive on this last of the 70-degree days this year. Car is running fine, pulls like a rocket off the line; just light blue smoke. Going to just ignore the smoke for a while... if I can. Prolly rings as I pulled the PCV out of the valve cover when I was warming it up and still had blue smoke.

 

A leak-down test would tell you exactly where the smoke is coming from

 

Good idea.

 

Damned few heads will let you run stock guideplates and have the tip of the rocker perfectly centered over each valve stem. Saw 'em in half, line everything up perfectly, tack 'em, remove and weld 'em, reinstall. Race builders have been doing it this way for years.
Or spend the money on the 2-piece units and weld them together when you have 'em set correctly.

 

Interesting. I didnt even know tat two piece guide plates were available.

I've been following this thread closely because of a problem that I had with my Dart Iron Eagle 210 cc heads. I never Gould keep cylinders 2 and 4 from binding the pushrods. I was going to try the stepped plates that the OP had problems with. Plac C was to grind off some hardened steel from the slot.

 

What has confounded me is DART documents say this style of guide plate is required for this cylinder head. When I look at application, it is for the 87-96 style heads (closer to L98). All cross-references on the guide plates say this is correct. The valve train runs silent but many of the rockers are not 'spot on' side-to-side. I am running roller rockers and assume that I had the same issues with the stamped steel rockers... just could not tell as easily (or did not know what to look for).