Head (gasket) scratcher

[Tim Smith]

Had a couple of hours this evening and decided to jump into the head gasket. All went pretty well with the exception of a couple of snapped exhaust studs... that is until I got a good look.

Didn't see much of a failure in the old head gasket. The head bolts were probably just in need of a re-torque as they seemed pretty loose. I still wanted to take a look inside though, because I've been getting some major blow by and just wanted to have a gander.

Well once I got the old gasket off, I realized that there were some big passageways that were getting blocked off by the old head gasket. When I compare the old head gasket to the new one, sure enough the new one has the holes cut out for the passageways. What in the? How has this motor not just up and ceased way back when the gasket was installed?



You can see the missing passageways in the upper left, as well as the lower middle and right. I'm counting four blocked holes. Probably oil returns but could be coolant. Needs further inspection tomorrow.

When I think about it, my father must have put this head on about 15 or 20 years ago. I'm sure I would have been eagerly bouncing around in the drivers seat at the time, distracting him from this minor inconsistency.

Any way, I just thought this was weird and thought I'd post up. I suppose this could have been causing the blow by but... well who knows how this thing hasn't just dropped dead on me. Guess I'm lucky.

[StX_Rovers]

I think that is to restrict the coolant flow in the front, near the water pump, to help the circulation go to the back of the head. At least, that is my theory having just installed a new head gasket on my wife's 88 and wondered about the same thing. In particular the engineers most likely wanted to be sure there was plenty of circulation between #2 and #3 cylinders as at that location the exhaust ports are next to each other. Note the greater distance between the bores, too.

[kevin-ct]

Hey Tim,

If you need any help I can stop by one day/night.

Let me know.

[daveb]

hey tim

good find, though I doubt it has caused you any grief. the 2.25 is a low stressed engine for the most part. leave it to an engineer to try to improve something that obviously works fine. put the new gasket on and torque correctly, and everything should be just ducky.

Had a couple of hours this evening and decided to jump into the head gasket.

[Tim Smith]

That is so bizarre STX. I can't believe engineers would modify flow so drastically as to completely cover up passageways with the head gasket. I'm still not sure these are coolant passageways as I didn't really get a good look at the residual goop that was in them. I'm not too clever at the fluid flow on a 2.25 so I suppose you could be right.

Just a little back story. This motor served in a 109 for ages as a local dump run truck. About five years ago, give or take, I yanked it out and tossed it into the lightweight where I actually used it on the highway. Gasp! Since then this thing has been developing blow by at an alarming rate. Lately I've been pulling trailers a bit more and had noticed the blow by becoming a little scary when I'm pushing the envelope. So bad in fact that the cabin would fill will a light smoke. <cough>

I'm hoping this is all related and that I don't actually need to do the rings. I had terrible compression prior to this but I guess I'll find out.

Hey Kevin,
I should have this one mostly packed away after work tonight but you are more than welcome to stop by. I've always got a couple of projects going that could use an extra set of hands. Feel up to a 109 frame over?

I'll drop you an email.

Cheers,
Tim

[Firemanshort]

I replaced the head gasket on my S3 2.25 a few years ago and noticed the same thing. I asked Frida of Turner Engineering what the deal was and she replied same as stated above. The blocked passages were in an effort to re-direct more coolant to center cylinder areas.

[Tim Smith]

That seems so weird to me.

This could have been saving me from something terrible. I've been fighting a pinging problem for ages. The timing is set as retarded as I can make it while still able to make power. The carb which is a Weber 34ICH is running as rich as I can make it but still, I've been unable to completely get rid of the pinging. Pulled the plugs and saw this.

Sorry for the poor image quality.



I've also gone through a few sets of points sooner than I thought normal so I bet that I'm running plugs that are too hot. These are Bosch Super's. Looks like the model Number is R0 491 but I can't seem to find that number with google. Guess I should find a cooler plug... Looking at the valves, the heat build up has been pretty severe.



Yeah I know. Ignorance was bliss.

[thixon]

Hey Tim, you probably already know this, but running hot plugs is likely not the cause of your burnt points.

Either your coil, or condensor are probably bad. Another possiblity is that, if you have a ballast resistor installed between the coil and the diizzy, its bad. I don't kow your set up, but if its stock, probably no ballast resistor? If its not stock, the lack of a ballast resistor may be the problem.

Also, running your card really rich is likely the cause of the deposits you show in the photos. The pinging could be caused by hot spots (all that crud). If you are in fact running really hot plugs, a glow plug effect can occur, causing precombustion (your pinging problem). If this is happening, you can sometimes see burn marks in the center of the piston (althoug I doubt you'd see the marks in a rover 2.25).

If you already knew this then disregard. It it helps, then great.

[Tim Smith]

I'm always learning Travis, so thanks. Sometimes I just need to think about something through a different interpretation. Then, only maybe, will I get it.

The coil, condenser, wires, plugs and points were swapped out with new parts about a year ago. I haven't been using the truck as a daily driver in the last year so I'm guessing that I've got less than 10,000 miles on the above parts.

The points have burnt out on me twice since I swapped all those parts in. Nicely melted point seats both times. One time I was able to clean up the seats but the second time I had to drop in new points. I even tried an electronic unit but that failed on me within about 50 miles. It was used so I didn't put much stock in the failure.

The residue I'm seeing is white and thick. I suppose it could be excess fuel deposits but I thought white deposits meant lean or hot burn. One of the plugs even has some of the isolator cracked off so I was just assuming that this was all due to a hot burn. Could the new ethanol fuel be playing a part with all of this?

I'm kinda' guessing at this point but I'll try some cooler plugs, give the thing a good tune up and rub my lucky rabbits foot. That should do it.

[bmohan55]

"If its not stock, the lack of a ballast resistor may be the problem."

Not to hi-jack but I have a resistor with my Accel super coil (PO set up), why is one needed? Just trying to understand the truck.
Thanks
Bob

[SafeAirOne]

Not to hi-jack but I have a resistor with my Accel super coil (PO set up), why is one needed? Just trying to understand the truck.
Thanks
Bob

See this new thread explaining the purpose of the ballast resistor.

[gudjeon]

I run a generic aftermarket electronic ignition coil, ballast resistor, Pertronix unit in the dizzy, and champion RN11YC4 plugs. Has been working flawlessly for about 4 years now. Before, I used this combo with points, and they stood up fine as well.

[Jeff Aronson]

Every so often the points on my Rovers seem to wear faster than in the past. I have the same issue with my '66 Corvair, too - one set did not seem to last all that long. Perhaps the issue is that the pressure on suppliers to make the highest quality points is down as only older cars even run points.

When you removed your head gasket, did you see the word "Petrol?" I once had a friend's father in law replace a head and gasket for me. It lasted only 5,000 miles because he put the gasket on upside down. The result was burned valves.

Your plugs look like mine did when I ran the car too advanced and when I had a lot of carbon piled up around the rings. Cleaning it off and adjusting the timing correctly did the trick; I've never had white tips plugs sinc then.

Good luck with your engine work.

Jeff

[Tim Smith]

Off to the races

That was easy. Well kinda'...

The snapped studs in the header proved to be more time consuming than I thought they would. Ended up drilling and rethreading them but wasn't happy with the fit, so I welded them in for safe keeping.



That must have taken a good hour of fiddling but once the head was in place, it was just a couple more bolts and the worst was done.

Gratuitous video clip.


Amazingly, that clip was the first turn of the key after all of this. I swear it. To think, I had that Weber in all kinds of unnatural positions through this little adventure and it still had fuel in it. Wow!

Have to adjust the valves and whatnot yet, but thought you folks might like to hear the happy ending.

Thanks for the thoughts on this one. Oh and excellent post on ignition ballasts SafeAirOne.