Well those of you that may have been following my threads know I am in the process of changing the cyl head on my 323. Well lets just say I did something I didnt think I could, I think I just smashed all the exhaust valves on the new head Got the new head all on and everything, it was SLIGHTLY different on the outside but everything bolted up fine, gasket holes matched etc. Was timing the cam the same as I did last time but all I got was some sputters and popping, OK timing is off I figure, I adjust it for the next hour or so , the last time I go to restart it when BANG BANG BANG BANG (along with the gentle tinkling sound of broken shrapnel hitting the driveway)...........................sigh.......... ok........ I walk back around and what do I see?? I see each exhaust rocker in a million pieces in the head, around the ground in front of the car and the roller lifters (didn't see them earlier but can see them REALLY good now, old head is just flat rockers) scattered everywhere. Well from what I figure the "new" used head had a higher performance valve train with higher lift valves that now made my former non-interference engine interference style, now I gotta rip this head off and check the pistons and valves, also I should add I tried timing it for almost 2 hours and each time was worse than the first, it would either just crank with no compression or it would sputter briefly along with some fire out the intake. Damnit, ah well, win some lose some eh? Pics of the carnage to follow.

 

Took the head off today, all the exhaust valves are stuck open, guess they are bent but on the bright side I do not see any damage to the pistons. Going to try and pull all the valves off my other head and install them in this one with the old camshaft as well, the valves in the newer head also appear to be slightly longer than the old ones. Does anyone have any info on cylinder head casting codes? Would like to see exactly why they were smashed.

 

I am sorry to hear of your troubles! I hope you get it back together.

Before you pull the valves off the old head take some measurement on how far the valves come out in reference to the deck. That would give you a bench mark.
Then when you have the valves and cams changed over do the measurement again. Then measure the clearance of the pistons to the deck. By adding/subtracting the numbers you will now if the configuration results in a interference or non interference set up.
(At least in theory, I have not done an engine built yet)

 

Oh man, that SUCKS!
I've not much experience in this area either, save helping my grandpa out a little with his porsche 924s rebuild.

Cylinder head codes and specs should be available somewhere, but I'm not sure where. Maybe a helpful Mazda tech could dig in their systems?

I'd try what tanprotege suggested, measure and compare the valve length differences yourself. You may be able to also compare the measurements to head specs and identify your replacement head...

 

Well after looking at things much closer I found why it all happened. Pic#1 shows the rocker arms from the new-used head, notice all the nice exploded bits AND roller rockers. Pic# 2 is what the old head had, definitely a lower performance economy head. Pic #3 shows the profile of the new head, notice the deck thickness. Pic #4 shows the deck of the old head, notice the height difference of the casting between the two exhaust valves in this pic and the previous. Pic #5 shows the difference in the valve lengths, new on left old on right and in the inset the difference between the valve springs again new on left and old on right.

I am going to install (If they fit) as much of the old valve train as I can onto this cylinder head and throw it back on, whats the worst that could happen? Already have smashed valves once and it survived, I guess the best that could happen is it runs and will have higher compression so more power Worst case is I still have a broken car.

 

I agree with your rationale.

Let me tell you how I killed a VW engine back in the days. There was a flea market and a guy had some used gauges for sale: a clock, and an oil thermometer. I picked them up and put them into my car. The temperature probe was a special dipstick. So the owner had to transfer the dipstick marks to the probe. I checked and the marks matched my dipstick's.

3 months later I had a flickering oil pressure light, checked the oil and that looked good. Eventually the light was always on and the engine seized.

I took that engine apart and at some point I decided to look at the dipstick again and I went white in my face. The marks were transferred incorrectly!
The probe was longer than the dipstick, but the marks were transferred after lining up the lower end! As a result the oil level dropped below the pick up of the pump. Lessen learned the hard way!

What's your favorite road in Tirol? In the late seventies I vacationed near Galtuer in the Paznauntal. Great memories!

Servus!

 

OH SNAP!! I'm sorry I am just seeing this thread now.

Sorry to hear, MT, but keep on chuggin'!!

 

Oh dont worry I am, I just have to wait till 1. the rain stops, its supposed to keep raining for the next week off and on (I HATE getting wet, swimming is ok, rain is BLECH if I get wet LOL) with some snow thrown in on Sat/Sun for good measure and then for 2. I need to go get ANOTHER camshaft from the junkyard, the one in the new head has a much higher lift and the used one I bought was trashed by the old head with the bad bearing journal. Did you know that the camshafts ride IN the head itself? As in there is no bushing or bearing, its just the metal of the head from what I can tell, I cant see any insert/bushing/bearing of any kind.......maybe I should wash the old head a bit to check though.

 

IT RUNS!!!!!!!!!!!!!!!! WOOHOO!!!!!!!!!!!! Had to go buy a second cylinder head for I could not get the first one I bought to work, just was too different for the rest of the engine. Bought it at 10am this morning and got it running at 11:30 Just finishing up with all the other little bits I had to take off and then re-torque the cylinder head bolts once it cools off. Will need to get the metal coolant pipe behind the exhaust manifold and an oil pan this year, both are so rusted I think they will leak soon, coolant pipe will probably fail catastrophically but also in a spectacular cloud of steam, been there done that with my old Saab, that was fun

The car does have a small stumble/miss though when you rev it up from idle, think it had it before though but its annoying and I am going to try and track it down. Does anyone know how to see if there are any codes pending/stored on the 323 in my sig? I would like to see if it says anything useful.

 

Glad to hear this! you must feel like yodeling!

Your miss may have to do with the EGR system or a small vacuum leak..

Servus!
Tan