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Engine Seized?

84K views 576 replies 50 participants last post by  PSk 
#1 · (Edited)
This evening, I did a few minor things to my '88 Veloce. I put some stop-leak in the radiator, some STP in the oil, and set out to hoon it for about 10-20 minutes (with the heater wide open and the top down) to let the stop-leak take effect. The car runs and drives great, and I was looking forward to a little starlight, top-down driving.

In less than 5 minutes, I was stopped at a traffic light on a hill when the engine died. I had the radio cranked pretty loud, and I thought I had simply killed it with bad clutch technique. I went to restart it, it caught and immediately died again. When I tried to crank it again, it turned over reluctantly...ok, something is wrong. I coasted it to a parking lot, walked back to the house to get my Avalanche and tools, and returned to the car.

Long story short, the starter could hardly turn the engine...even with the Avalanche connected via jumper cables. There were no indications prior to the engine stopping: oil pressure, electrical, temp...all indicated normal, with no warning lights. The radiator cap and oil cap were securely fastened. In fact, I hadn't even got the engine up to temperature to circulate the stop-leak; I can still see it floating in the neck of the radiator.

I towed it home, put it in the driveway, and put the battery charger on it. It showed 59% charge, which seems reasonable considering the cranking attempts, and towing it home with the flashers on. I pulled the plugs and put a scope down the holes...nothing out of the ordinary; the plugs show normal proper wear. I cranked it briefly with the plugs out, but again, would barely turn.

There are no unusual leaks, it made no strange noises, and as I mentioned above, it gave no indication of impending failure.

It would seem that I have a seized engine (with a radiator containing uncirculated stop-leak)...and I don't know why. I guess another possibility is that the starter suddenly went bad, but that doesn't explain the first failed start attempt.

It's going to sit tonight while I ponder this. I cannot think of anything I would have done to cause this, but coincidence is rare. I searched the BB and internet for relevant information before starting this thread, but obviously found nothing useful.

If anyone has any wisdom, I'm all ears.

NOTE: This story has a happy ending. See post #541 HERE for a summary of the project and lessons learned.
 
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#229 ·
I have no Alfa shop in the area, especially one that could drill oil passages in the block. I'll just have to go with the stock oil system. The good news is that our parts washer at work has nozzles that should allow me to flush the oil passages in the crank and block.

I'm pretty diligent about oil changes in all my vintage autos. It's a positive habit transfer from owning '55 Chevys and VW bugs that don't even have an oil filter! I don't usually run STP in each oil change, though. There wasn't sludge or metal in the pan, just some crud inside the crank.

There's no accounting for how this engine was treated by a PO.
 
#230 ·
While I'm waiting for Classic Alfa to ship my order, I've been cleaning up the engine parts, removing old gaskets and adhesive, and cleaning carbon from liners, pistons, and valves.

I noticed this discoloration near the top of liner #2. It doesn't feel as smooth as the shiny surface of the rest of the liner. Is this anything to be concerned about?



The other three liners look fine.
 
#232 · (Edited)
Piston and rings look good; piston not the most carboned-up of the four. I'm replacing the rings, while I have everything apart.

I guess I'm concerned about the surface of the liner, and whether it will cause problems.
 
#233 · (Edited)
Get the best Hastings rings. A bit more expensive, but very good and worth it.

To install new rings you will need to hone the cylinders. The V-shaped scratch pattern is key to getting the rings to seal. They wear and the cylinders wear together for a perfect fit. If you don't know about this, get your engine shop to hone the cylinders.

You also likely have a small ridge at the top of the cylinders - this is where the piston rings do not quite get to the top of the cylinder, so no wear. You will need to remove this or you can break a ring installing. Again have your shop take care of this.

Break-in is critical to getting rings to seal. There are threads on it - use the right oil, etc. RJ's thread will help you, as will JK's book.

While you have the heads off, you might consider getting the valve seats ground, and perhaps the guides replaced. And use the green Viton valve seals!!

You can notch the heads to allow greater cam clearance, allowing you to use RJ's super good custom cams. But you will need to install the valve guide in a special way to allow the higher lift of these cams. RJ can advise in great detail. Richard is quite an expert with a fully equipped shop. I shipped my head from SoCal to Florida to have him do all these things.

Thats Richard Jameson of RJ Racing. In the suppliers list.

Robert
 
#237 ·
Get the best Hastings rings. A bit more expensive, but very good and worth it.

To install new rings you will need to hone the cylinders. The V-shaped scratch pattern is key to getting the rings to seal. They wear and the cylinders wear together for a perfect fit. If you don't know about this, get your engine shop to hone the cylinders.

Robert
The hone grit needs to match what type of rings you get. For example chromed rings need the cylinder honed to a different grit then cast iron rings need. If the cylinders are not honed to the correct grit for the rings. They will either never seat in.
 
#236 ·
@60sRacer, I"ve got the Hastings rings. I have no problem with honing the liners to get the crosshatch right. there was no ridge on any of the liners...all four pistons slid smoothly out of the top.

The valve seats on the heads look good; I'll lap them when I replace the valves.

@spiderserie4, Do you think that liner discoloration is due to coolant?...it's up in the combustion area, next to the head. The head itself exhibits no such surface condition.

I'm wondering if I shouldn't just replace that liner. Is there any way to look at a piston or liner to tell if it's blue, pink, or green?

@PSk, The engine wasn't hydrolocked, but seized at the crank.
 
#239 ·
The hone grit needs to match what type of rings you get. For example chromed rings need the cylinder honed to a different grit then cast iron rings need. If the cylinders are not honed to the correct grit for the rings. They will either never seat in.
Do you choose the grit based upon the top compression ring? When I talked to the Hastings rep I was offered a choice of both top and second rings in cast iron or the top one chrome and the second iron. I am under the impression that the second ring is usually CI in the Hastings set.
 
#242 · (Edited)
Another dumb question: the valve guide seals have really hardened, and so far, I've been unsuccessful getting them off. I was reluctant to get too aggressive, for fear of damaging the guides. Any suggestions?

EDIT: Okay, a little heat gun action made the old seals pliable enough to pull off the guides. My engine has seals on intake and exhaust valve guides...I read somewhere that Alfa didn't start doing that until the S4's. Classic Alfa and Centerline both have green valve guide seals.
 
#243 ·
If you might ever want to get one of RJ's super cam sets, now it the time to prepare. All you need is to replace the valve guides, and maybe shorten the valve keepers. Also, if you notch the cam follower bores (simple machine shop job) you have access to the best high-lift cams. See RJ's sticky thread for all the details.

I'm not pushing any of this. I just want to encourage you to make these choices intentionally, rather than by default.

Robert
 
#247 · (Edited)
Yes.The seals on the exhaust side started on the S4's. I don't know how many miles are on the engine. But the Bosch injected 4 cylinders usually burned an exhaust valve between 50,000 to 80,000 miles. The average milage was around 70,000. I worked one these cars when they were new at several Alfa dealers and independent shops.

The reason they did this was because of 2 things. 1st. The valves not being checked and adjusted at 30,000 miles like there suppose to be. The 2nd and main reason is how lean they were set up to run to pass emissions. The car was set to have a c/o of .20 with the O2 sensor plug in. You would set the mixture to around .70 percent then when you plug in the O2 sensor it pulled it down to .20.

Nowadays I set the mixture to around 1.5 percent with the O2 unplug. If it has to pass emissions you will need to set it the the factory setting.

Also keep in mind that most of these cars were daily drivers when new. Most of my customers back then put an average of 20,000 to 30,000 miles a year.

Without knowing your milage. I know it has had at least one valve job. Also a lot of shops started using the intake guides on the exhaust to reduce the tendency to suck oil through the valve guide. This is the reason Alfa did it.

You need to let the machine shop check the guides. Especially the exhaust as they are probably worn.

Oh. Only use the green seals. If you have to replace the guides get the correct ones that use the green seals.
 
#248 ·
@Jim G, the car has 95,338 miles on it. The engine having a previous valve job makes sense, given the evidence of other work that's been done.

Nowadays I set the mixture to around 1.5 percent with the O2 unplug. If it has to pass emissions you will need to set it the the factory setting.
Where are you setting this mixture? I don't have an emissions test to contend with.

The head certainly has intake-style valve guides on the exhaust side too. It makes me wonder where this car resided before it came to Missouri. There's certainly no machine shop around here that will do that sort of work on an Alfa!
 
#254 ·
@Jim G, the car has 95,338 miles on it. The engine having a previous valve job makes sense, given the evidence of other work that's been done.



Where are you setting this mixture? I don't have an emissions test to contend with.

The head certainly has intake-style valve guides on the exhaust side too. It makes me wonder where this car resided before it came to Missouri. There's certainly no machine shop around here that will do that sort of work on an Alfa!

On the airflow meter, on top by where the rubber hose is connected there is a round aluminum plug. If it is smooth on top. If its been adjusted before it will already have one or two holes in it. Drill 2 1/8 inch holes, about an 1/8inch deep so you can pull it straight up with a pair of needle nose pliers. Underneath is an allen screw. This is what you use to adjust it. Unplug the O2 sensor and using a AFI meter set it to around 1-1/2 percent. There are conversion charts on the internet you can print out. After its set plug the O2 sensor back in. If the value on the meter drops the sensor works. If it doesn't its not working. It doesn't really matter if it is or isn't working unless you need to pass emissions.

This factory manual also tells you how to do this.
 
#249 ·
Now would certainly be the time to replace the guides. You can R&R them relatively easily. Here is a youtube video with the method I use for removing them:



If you want to install the new guides yourself it is best to make a simple tool (I can't find my drawing at the moment but it's in JKs book) to protect the end and set to the proper depth. I like to freeze them (in the freezer for a couple days). They will drive in pretty easily. Then they need to be reamed to size. If all this is too daunting, take it to a competent shop.
 
#253 ·
Now would certainly be the time to replace the guides. You can R&R them relatively easily. Here is a youtube video with the method I use for removing them:
.
That's doing the job backwards. I thread the other end -the valve head end- screw in a bolt, and drive the guide out from the camshaft side. This eliminates dragging the crummy end of the valve guide through the bore in the cylinder head.
 
#250 ·
I ran across that Youtube video when I was trying to get the valve guide seals out. He makes it look easy.

At this point, I'm probably not going to replace the guides. Visually, they look to be in good shape. Since I appear to have intake guides in the exhaust, I'm betting on the fact that they were replaced during some previous maintenance. That kind of detail work is a bit overwhelming for me at the moment; I may do more harm than good...and I need to get this thing back on the road.

There are no shops around here that will do that kind of work on a vintage European engine, much less an Alfa. I envy you guys that can take stuff to an Alfa engine guy, or an Alfa trans guy. I have none of that here. What import shops we do have are simply 'pull-and-replace' guys, and they only work on British or German import stuff. I've asked, they won't work on Alfas.

There used to be a place in Kansas City that would do work, but their website has gone dark, and they don't answer emails or phone calls anymore.
 
#251 ·
Good machine shops can install K-line valve guide inserts in your valve guides. This will save you the trouble of removing and replacing them. If you are going to remove them yourself, I recommend heating the head before you drive the guides out (same goes for driving new ones back in). This will make things a lot easier. Be sure and check your head for flatness using a machine-shop quality straight edge and feeler gauges. There are bound to be some hot-rod guys in your town. Ask them what machine shops they use and you'll find some people who can do all this work on your cylinder head. Hot-rodders may be never seen a Alfa head before (not all that likely but still possible) but they can usually be counted on to know what to do, especially given the plethora of ohc cylinder heads on modern cars.

If you want to have a shop do this work for you, I can highly recommend Robert Rogers in Dallas. He's as good as they come. Putting your head in a box and sending it to someone like Robert will solve a multitude of problems.

shadetreeenginetrics
 
#252 ·
I'd suggest you look into shipping costs. I used Greyhound (!!??) to get my head from NorCal to LA at a surprisingly low cost where John Shankle did a wonder job. In your case, look into shipping to Florida - Rick Jameson of RJ Racing - who can do even better wonders.

Robert
 
#255 ·

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#257 ·
I'm thinking ahead a bit here, regarding valve shims.

I've kept everything bagged and labelled. I have the valves, springs, tappets, shims, etc. for each valve.

My question is: if I install different valves, will I have to re-shim them? Is the purpose of shims to compensate for valve stem length variations, or for differences in valve seat placement? I'm not replacing or resurfacing the seats, just lapping the valves.

I've read through several threads regarding shims, but I'm confused regarding how the measurements are taken, and how the required shim size is calculated.
 
#258 ·
Yes you will need different shims. Its really easy to calculate once you have done one. Measure the gap, and add shim thickness if the gap is too large, remove if too small. Its a bit trial and error but not difficult
 
#260 ·
gap between the cam circle and the top of the cam follower. Put the cams so that the lobe is straight up, and measure with feeler gauge the gap between the cam and the top of the follower. The shims under the follower adjust that gap
 
#262 ·
Putting new valves against old seats is poor practice. When an engine is down this far for a rebuild the head should be also be rebuilt.
WHAT? You are proposing replacement of the valve seats? Do you know anyone who can that job? It is common practice to replace vales and just re-cut or grind the seats.
 
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