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 Post subject: To rebuild or to not rebuild...
PostPosted: Thu Feb 12, 2015 9:49 pm 
Cams + Headers

Joined: Tue Jan 27, 2015 9:46 pm
Posts: 73
You guys gave such good advice with my tire question that I'm going to fire another one your way. As I alluded, I'm going on a 5000-mile road trip in June, so I'm getting the car prepped for that. I know everyone says the B18 is bulletproof, but I just want to be sure.

When I first bought the car, I warmed it up and did a compression test and got the following results:
#1 - 120 psi
#2 - 110 psi
#3 - 128 psi
#4 - 118 psi

Pretty low across the board. Then I remembered the previous owner saying he had attempted to set the valve lash, couldn't figure it out and gave up. So I adjusted the valves and retested the compression.

#1 - 126 psi
#2 - 120 psi
#3 - 130 psi
#4 - 111 psi

I think I must have messed up the valve lash #4 since compression dropped after adjustment. My hands were pretty much numb by that point, since it was a pretty damn cold day. I'll have to fiddle with it again.

Wanting to dig a little deeper, I did a leak down test today. Here are my results:

#1 - 8.5%
#2 - 10%
#3 - 7.2%
#4 - 14.3%

They are fairly consistent with the compression test numbers. I'll redo #4 after I re-adjust the valve lash for that cylinder. Overall these numbers look pretty good. 5-10% leak is the standard, so I'm not too far off.

The air seemed to be leaking primarily out of the pushrod tubes. I would assume that would mean that the air was leaking out past the rings, into the crankcase then out the pushrod tubes?

It also sounded a bit like air was coming out of the cylinders next to the one I was testing. That makes me think head gasket. Maybe that's why the air is coming out the pushrod tubes too?

I'd like to pull the engine anyway to clean it up, clean the engine bay up, and replace a few gaskets (exhaust gasket is leaking for sure). If you had a big road trip coming up what would you do? Pull it, replace the HG and the other usual gaskets? Complete rebuild? Leave it as is, buy an AMA membership and if I make it all the way, buy a lottery ticket?

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1967 Volvo 122S
1969 Lotus Elan +2
2000 Subaru Impreza


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 Post subject: Re: To rebuild or to not rebuild...
PostPosted: Fri Feb 13, 2015 10:51 am 
Bone stock

Joined: Tue Aug 06, 2013 1:07 pm
Posts: 6
Location: Austin, Texas
I think of compression degradation as a slow chronic problem if it's ring wear, not an acute breakdown event. Unless of course the problem is the head gasket....

Dean


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 Post subject: Re: To rebuild or to not rebuild...
PostPosted: Fri Feb 13, 2015 8:46 pm 
Haha, I just built a W24 Octo-Turbo, now what?!
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Joined: Wed Jun 14, 2006 4:19 pm
Posts: 3126
Location: Lethbridge, AB
Those values are quite low. Any idea as to the mileage? Do you have access to a leak-down tester to provide a more detailed evaluation of the internals? Set the valves to 16 thou when cold...a bit tight seems to work better. Don't forget to check for rocker wear. The tips of the rocker arms wear a groove and you can't set the valves properly. Just unbolt the rocker shaft and check them for wear. Some grind down the end of a feeler gauge so that it is just the width of the valve stem (5/16") - it's a temporary fix. Many machine shops no longer offer to reprofile your rockers as they have tossed out the equipment. It's easy to do on an inverted belt sander with a 220 grit belt. If you have a stationary belt sander use that. I've even used the side of a fine wheel on a bench grinder...this is scary.

How's the power?

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Coburn Performance - OCD comes naturally.


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 Post subject: Re: To rebuild or to not rebuild...
PostPosted: Tue Feb 17, 2015 12:37 pm 
Cams + Headers

Joined: Tue Jan 27, 2015 9:46 pm
Posts: 73
Thanks for the advice guys. I've made the decision to either source a new motor or rebuild.

That being said, anyone have a decent motor kicking around? :D

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1967 Volvo 122S
1969 Lotus Elan +2
2000 Subaru Impreza


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 Post subject: Re: To rebuild or to not rebuild...
PostPosted: Tue Feb 17, 2015 3:15 pm 
Haha, I just built a W24 Octo-Turbo, now what?!
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Joined: Wed Jun 14, 2006 4:19 pm
Posts: 3126
Location: Lethbridge, AB
Nothing kicking around. Tripping over a few, but none are for sale. Rebuilding is pretty straight forward. I have a "How To" in that section of this forum.

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 Post subject: Re: To rebuild or to not rebuild...
PostPosted: Tue Feb 17, 2015 7:57 pm 
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Joined: Tue Jan 27, 2015 9:46 pm
Posts: 73
Your how-to is actually how I found this site! I was looking for rebuild information and read your thread and only after realized that it was a Calgary-based forum.

I don't have much experience rebuilding engines. My Chump Car team rebuilt the engine in our Nissan 240SX, but honestly I don't remember much and it was a DOHC engine so some obvious differences, so I need some guidance.

I have a friend who will help me reassemble the engine, so I'm just going to have the machine work done and have him help me put it all back together.

Here is what the machine shop quoted me:

Bottom end:
Rebore $30 each
Cleaning $110
Crack inspection $55
Cam bearing install $55
Resurface deck $110
Torque mains $55
Bottom end TOTAL: $505

Head:
Tear down and inspect $55
Resurface head $72
3 angle valve job $110
Test valve spring pressures $55
Final assembly $110
Head TOTAL:$292

How does that list look?

And obviously I will need to buy some new parts. Here is what I came up with:

Gaskets (head, intake/exhaust, water pump, distributor, thermostat, valve cover, oil pan, timing cover, rear crank housing, distributor, fuel pump... what did I miss?)
Main bearings
Rod bearings
Camshaft bearings
Valve springs
Head studs
Piston rings
Water pump
Oil pump
Timing gears
Lifters

What else?

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1967 Volvo 122S
1969 Lotus Elan +2
2000 Subaru Impreza


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 Post subject: Re: To rebuild or to not rebuild...
PostPosted: Wed Feb 18, 2015 8:41 am 
Haha, I just built a W24 Octo-Turbo, now what?!
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Joined: Wed Dec 21, 2005 8:40 pm
Posts: 3482
Location: Calgary, Ab
You ARE going to need a camshaft in your build, it will have at least one lobe wiped out. You may want to upgrade valve springs if you upgrade the camshaft beyond a D cam: I have a set of ISKY springs that will take whatever cam you like, but you'll need to spend a bit more money cutting dual valve spring pads into the head and they're probably more than you need. You're probably going to want to raise compression a little bit if you're upgrading the cam, you get this by milling the head. You'll want to get a 3 angle valve job done, for sure, and if you can spend some time in the head with cartridge rolls and a die grinder, do it. If you're boring the block you're going to need pistons, you're not getting away from that. You may be able to get away with a hone and new rings, but the pistons will be sloppy and there's no guarantee of a good ring seal unless the block is perfect. Do it right, and buy pistons. You probably don't need head studs, the stock bolts will do and I believe the bolts on the B20 are re-usable but if you're going through the trouble you might as well get them and new bolts for the main bearings and flywheel as well. You'll want to upgrade to more modern double-lip main bearing seals, which requires a machining operation on the timing cover (someone's going to have to clarify if you need to do the rear main too). You will want to make sure you get some good rockers, as they wear out. They can be cleaned up by an experienced hand: I'm not sure if you can even get good new ones although I know there are performance aftermarket pieces out there for a bit of $$$. I'm assuming you want to keep it as close to stock as possible, so I haven't mentioned anything outrageous.

Once all this is done, you'll have to look a the condition of the other systems. How is your radiator & cooling system (don't forget the heater core and heater control valve)? What kind of shape is your distributor in - bushings, weights, springs? How are your carburators - bushings, shafts, jetting? Have you got a decent exhaust? Make sure you upgrade at least the exhaust in proportion to the upgrades you throw at the engine, the rest is fine in stock trim as long as it's tuned properly. Have a close look at your generator, swap it to an alternator if you have the ability, and you can get a more modern reduction starter from a 700/900 to save some weight and add reliability. If you're unsure about your distributor, you can try a rebuild or spend the coin on a 123 ignition distributor. It's also very important that you KNOW what the inside of your fuel tank looks like - if it's rusty, you're asking for trouble. You can buy new or you can have it cleaned and coated for about the same amount. Drain it, pull the level sender, and have a CLOSE look inside with a flashlight.

Research this list and re-evaluate your budget. There are some things you'll want to take care of here if you're going on a long trip, and this might be enough to dissuade you from a full-on rebuild at the moment.


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 Post subject: Re: To rebuild or to not rebuild...
PostPosted: Wed Feb 18, 2015 9:33 am 
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Joined: Tue Jan 27, 2015 9:46 pm
Posts: 73
Thanks for the very helpful post. I think you've completely scared me away from rebuilding, haha. I know of one, possibly two strong running motors for sale, so that might be the way to go. Just buy one of those, give it a refresh with some new gaskets, etc, rather than rebuilding.

As for the other items you mentioned:

- Radiator: Got one from an early 142, which is in really good shape with no leaks. I'm going to take it into the rad shop to have it cleaned. No idea on heater core or control valve.
- Distributor: I'll need to investigate this more on whichever engine I decide to go with.
- Carbs: I'm buying the rebuild kit from ipd. My father in law has rebuilt many of these, so he'll give me a hand with that.
- Exhaust: Was replaced by previous owner just before I bought it.
- Alternator: I have the Swedish Embassy bracket and AC Delco alternator ready to go.
- Starter: I'll have to look into replacing the starter. Never thought about that.
- Fuel tank: I drained the tank when I first got the car and there was no rust that came out of it. But I will pull the sender and get a close look so that I'm absolutely certain.

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1967 Volvo 122S
1969 Lotus Elan +2
2000 Subaru Impreza


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 Post subject: Re: To rebuild or to not rebuild...
PostPosted: Wed Feb 18, 2015 10:41 am 
Haha, I just built a W24 Octo-Turbo, now what?!
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Joined: Wed Jun 14, 2006 4:19 pm
Posts: 3126
Location: Lethbridge, AB
Your engine quote is fine - about what I have to pay. The difference is all in the details. Things like who's running the valve seat cutter. I get my heads done with 60 thou seats on the intake and just a little less than 100 thou on the exhausts. You only get MAX compression out of the head - the base compression number comes from decking the block. You need to get the piston to head clearance right FIRST. So lets set the pistons to be 30 thou from the head (a little further back if you're going to up the red line...this needs better rods or M rods at least). Then you set the SCR by working on the compression chamber. With a stock head gasket, this means the pistons will be out of the block by a bit (around 10 thou IIRC).

Buying someone else's "built" motor is pretty sketchy in my opinion. I've had a lot of these apart and seen all manner of odd things that have been done to rebuilt engines. Things like wrist pin clips that were missing, knurled pistons and pistons with groves filed (yes, by hand) to try to trap some oil. Volvo owners tend to be cheap - so your results may vary.

You need a good machine shop to put in those famous double valve springs...how do they set spring pressure to be consistent? I've got the tool and use a drill to cut the seats - you have to do a bit more measuring to get this exactly right, and it's done after the seats are cut. It's not complicated, but I'm sort of busy, so let's move along.

If you're doing your own head - don't touch the shape of the exhaust port. Have the machinist take a deep 70° cut into the bowl and clean that up and blend it in and do the best you can with the SSR. Ports react to shape not polish - and it's already too large. Bigger is worse.

Parts can be gathered from many places - compare prices...your eyes will water and your pocket book will cry.

Rebuilding SU's is NOT just putting a "kit" in them. They wear the throttle shafts causing them to leak unmetered air and resulting in carbs that can't be tuned. Take the return springs off and see if the shafts wiggle - if they do take them off and send them to Rhys Kent or Joe Curto to have new shafts installed and the bodies re-bushed. I've done them in my garage...but let's not advise people to do these sorts of things. These guys are the best.

The last engine I built I charged over $6K for and wouldn't do another one for a penny less - in fact this was a full blown build done for a bargain. Most serious builders would charge about $1K more than that value - this is a fully spec'ed engine with the best of the best and a real 160 hp at the crank. Nothing used, nothing left to chance.

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Coburn Performance - OCD comes naturally.


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 Post subject: Re: To rebuild or to not rebuild...
PostPosted: Mon Mar 09, 2015 4:55 pm 
Somehow completely sideways in 4th

Joined: Mon Aug 06, 2007 10:27 am
Posts: 211
Location: edm
122_Canuck wrote:
Those values are quite low. Any idea as to the mileage? Do you have access to a leak-down tester to provide a more detailed evaluation of the internals? Set the valves to 16 thou when cold...a bit tight seems to work better. Don't forget to check for rocker wear. The tips of the rocker arms wear a groove and you can't set the valves properly. Just unbolt the rocker shaft and check them for wear. Some grind down the end of a feeler gauge so that it is just the width of the valve stem (5/16") - it's a temporary fix. Many machine shops no longer offer to reprofile your rockers as they have tossed out the equipment. It's easy to do on an inverted belt sander with a 220 grit belt. If you have a stationary belt sander use that. I've even used the side of a fine wheel on a bench grinder...this is scary.

How's the power?


I've done both my sets on a piece of black sandpaper on the edge of the bench, side to side. Stopped with the last imprint of the wear pattern just visible in good light. Great finish, minimal metal removal. I think that makes up for any supposed lack of geometry.

Which reminds me, I chose to remove the pushrods for inspection and cleaning (more or less useless because they are not oil through)... Well... be aware it's quick risky if you let you mind wander. You have to use judgement and a bit of a badly leveraged motion, to keep them from pulling up the lifters from a sort of stiction. I've heard people complain the lifters stick in... Well, not in my experience. I think it was a close call... Can't remember, but I *think* that there was a risk just in removing the rocker shaft


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 Post subject: Re: To rebuild or to not rebuild...
PostPosted: Tue Apr 07, 2015 8:20 am 
0-60 in VERY FAST

Joined: Tue Aug 13, 2013 1:14 pm
Posts: 193
Location: Regina, SK
+1 for Rhys Kent. I sent my SU's to him and he rebuilt them to a high standard. He's very easy to deal with, a great guy overall. He doles out extra Volvo advice if you ask nicely! :)

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David
1967 Volvo 131 B18D M41


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