I think the auto repair deity finally has put a pox on me....

Finally got the O/S Valve head on the Hpak Duster, everything looked great...got the valves lashed... dialed the timing and carb back in...
Took it for a road test, and noticed a miss... ran back home put a vacc gauge on it (my spare)...sure enough wobbly needle, 15" of vacc...

Today I warmed it up and did a compression test...numbers were good across the board except cylinder #4...
1)145
2)142
3)142
4)10
5)140
6)140

Ran the wet check on #4...still 10...

Ran the leakdown test....no bubbles in the radiator, nothing out the tailpipe, nothing out the intake manifold....but it sure hisses a lot in the block....

Looks like I'll have to pull the engine again and do the rings...oddly it was cylinder #5 and a lunched valve and guide that did it last time....

If that wasn't adding insult to injury, the heater blower stopped working about the same time as the ignition miss...

If I had a 3rd car for a few months, I'd really be temped to pull beater valiant's motor, put the O/S head on it and run it in the duster...

Hmmmm....

-D.Idiot

Bummer. Need anything?

CJ

I should've just come down for the ABT's... I think my karma would've improved...

More soon,

-D.Idiot

If you need me, I am faithfully at your service!




~THOR~

_________________
1984 D100 Shorty Custom
Certified Auto Appraiser - RevItUp Classic Appraisals
President - Cherry City Bombers CC
Part of Tyrde-Browne Racing

I just borrowed a third car so I can rebuild my slant...

If you could PM me the details on your O/S valve head, I would like to see it. Thanks.

_________________

Sometimes.... the cards just come-up wrong.
Take a deep breath, "hunker-down" and go at it again.
Let us know what you find when you crack it back open.
DD

O/S head?

_________________
'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick

Dang, that really sucks. This is your 2.2L/198 rod motor? Will be interested in the autopsy results...

Seems like you changed the head, so maybe there is a flaw on the #4 valves or valvetrain or head gasket (into lifter valley?) that is causing the low comp? Would check all that before getting into rings/pistons.

Lou

_________________
Home of Slant6-powered fun machines since 1988

OK backing up a bit...

O/S = Oversize Valve head...

This isn't the still to be put together 198 long rod motor... this is the original build I put together for the duster back in 2001, that evolved with a change to dutra duals and the Hpak one summer....

Original problem was I ended up with a nasty 'miss' on the highway doing the speed limit... did a compression test and found the #5 cylinder to be fairly low, compression wet test didn't bring the number up...leakdown test could be heard plainly through the rear back tail pipe...

Teardown revealed that 1) there was a hair size burnline across the exhaust guide face, and 2)the #5 exhaust valve guide was loose (about 3/16" lower than it's buddies in the neighboring cylinders....

So I figured this was as good a time as any to finally pitch the stock valves for the set of SI stainless vavles I had bought a few years back...
The machine shop found on autopsy that 2 more exhaust guides were a bit loose (#2, and 3)... so I had those replaced, had opted to put stainless seats put in for the exhaust seats (I'm pretty sure that the original hardened seats wouldn't have been hardened after a grinding...)

At first I had thought it was a vacc. leak, but doing the usual checks showed I had put the 'stack' together correctly with no leaks. My theory at this point is: #5's rings were OK, but failed to seal due to the exhaust valve...now with the new head #4 had better sealing and the rings were almost ready to go on that one.... condition of the bore were a bit smooth with a little faint indication that they had crosshatching at one time, the lip of the bore barely has any ridge in the cylinders.....

I'm currently mulling over my options...

#1) Beater Valaint get me to work fine but has the 'old suspension' random shuffle, then engine is fresh.

#2) Hpak Duster's suspension, gear box and tires are all new/refurbished and it hugs the road good...but the engine has a dead hole...

#3) I have the time to pull the duster engine do a rehone and re-ring and see what happens...

#4) If I had a third vehicle and a couple of weekends(I have had some offers am still thinking about it). I could pull BV's engine...put the duster head and Hpak setup on it...drop it into the duster (I think the cam in that build would be happier and the cast crank would love the revs in the 'pak' zone...)...that way I can do the things that need to happen to the BV (suspension rebuild, steering box rebuild, swap to disc brakes and the 8.25" rearend, and drop in the refreshed Duster engine...)



-D.Idiot