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I have a 1967 122S with a B18D motor.
Since I am planning on sending the head out to a machine shop to be checked-out, are there any problems having the head milled to 86.2mm (B18B spec.) from 88mm (B18D spec.)
Also thinking this would be a good time to have harden valve seats installed.
Is there anything else to upgrade, like maybe B20 style valve guides with the improved valve guide seals ?? ....
Thanks all
Peter
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It seems like the simple solution would be to swap a B20 head in place of the B18. Then you get all the goodies. Kayo.
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posted by
someone claiming to be friendly
on
Wed Jun 1 22:08 CST 2016 [ RELATED]
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I just paid a visit to
V-P. The new Abarth type stainless exhaust system is BEAUTIFUL, and moderately priced.
Fred
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No problem shaving it to B18B thickness. That's all Volvo did.
You cannot put B20 guides into a B18 head, but you can definitely have your machine shop turn the B18 guides to accept stem seals -- not B20 seals, but they'll be able to provide the correct ones.
Absolutely have exhaust seat inserts fitted.
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Thanks Phil, that's just the type of feedback I was looking for.
So yer saying the machine shop can mill the tops of the B18 valve guides to accept a B20 "style" generic valve stem seal ?
And is there a significant advantage to this style of seal over the B18 "umbrella"style "oil control" seal ?? i.e., is it worth the machine shop cost ??
Thanks
Peter
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I would get Phil to weld the exhaust ports up BEFORE you shave it if you have the money. You can get guides that allow you to run B20 valves and seals + with a proper exhaust porting, the fuel economy boost pays for itself.
--
69 142S Overdrive + 69 164S Manual
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B20Paul, I don't understand what welding the exhaust ports has to do with shaving the deck height.
My goal is to bring my B18D up to B18B specs.
As far as I know, the only difference between the two motors is compression ratio (hence decking the head) and a different camshaft.(still trying to decide about that one)
I am not interested in changing the valves.
I am curious to know if the B20 style valve seals are a real improvement over the B18 "umbrella" style valve seals.
I believe Phil said that the B18 valve guides could be machined to accept B20 style valve seals because the B20 valve guides would not work in a B18 head.
From what I've read so far, it seems that for a non-race use motor, the head porting is okay.
Hope to find a B20 motor someday and build that up, but for now I need to work with what I got.
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Welding up the exhaust port floor is stage 1 to porting the head, after welding, the head will be warped and need straightening, so if you are ever going to use that head for a decent increase in performance, it is step one.
If you are doing as little as possible to your motor, why shave the head to B18B thickness? Healthy stock B18B are a pain because they tend to run on and demand 100 octane. Just leave it thick and use regular gas. Cam and compression are tied together too, if you have 10:1 compression, you must use atleast a C cam.
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69 142S Overdrive + 69 164S Manual
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Thanks for the clarification on welding-up the exhaust port. I have read up on that type of port work, but port work is not in the budget for now.
I received the engine in a partially dismantled condition (head off, etc)so I my thinking was since the head would be going to a machine shop to get checked out, why not have the head decked for what I hope is a modest fee.
My previous drivers were both B18D motors ('65,'66 and now '67).
I used to restore vintage Volvo's for a living and never came across a pinging problem with the B18B's that came in the P1800's.
Just trying to make my current project more like a 123GT as I go along.
Any thoughts on the B18 vs B20 valve stem seals ??
Thanks
Peter
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For unleaded fuel, you really need to install hard exhaust seats, they require either B20E exhaust valves or better, so you go to the guides that let you put the smaller stem B20 valves in, this adds up to a lot of money, and you can't go back and weld the head latter.
Alternately, you leave the compression low and drive it casually and you won't need to spend all that money. It's the chamfer on the top of the guide that is the primary oil seal in a B18, you need 4 for the intakes atleast, but they are cheap. With the money you save, you put that towards your future performance/economy engine build.
Actual 10:1 B18B don't ping because the timing is fairly retarded throught the rev range and they still demand 100 octane to do it. The thick B18A/D head is desirable for porting for performance too, but once you mow it down, it's usefullness is limited.
--
69 142S Overdrive + 69 164S Manual
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If I read you right, are you saying that harden valve seats are not available for B18 style valves ?
'67 122S, working on a mystery B18
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They are absolutely available. I've built a fair number of street performance B18s, and there's been no problem with fitting exhaust seat inserts.
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Thanks for that answer Phil, I thought they would be available.
It's been many years since I've been to a machine shop with one of these heads.
I'd like to ask ya one more question if you don't mind.
In order to complete the transformation from my B18D to a B18B motor, I'm guessing I should change the camshaft too.
Do you have any recommendations for a camshaft upgrade. ? C,D,K, etc. ??
Looking for a peppy, streetable motor.
Will be running dual SU's and '67 style dual downpipe exhaust manifold.
Haven't decided what to do about exhaust/muffler yet, but I'm open to suggestions.
Thanks
Peter
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C is stock for a late type B18B. K will give you noticeably more pep, and is a more modern cam.
You'll want to use the dual head pipe exhaust manifold (the integrated intake/exhaust that doesn't have the auxiliary butterflies is the best). I'd recommend a 2" system behind the head pipes, with a straight through resonator up front and a straight through muffler in back.
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My '67 already has the dual head pipe exhaust manifold (W/O the dreaded aux. valves).
I'll try a "K" cam then. Any good sources for one ? it's a bit confusing out there in the Cam world.
If you have any sources for a sport exhaust system, please share.
Thanks a bunch
Peter
544, 122, 145, 240, now 850
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I would check with VP-Autoparts for both the cam and the exhaust. The K cam is native to the '74 140 series, which I believe they support. I'm pretty sure they carry a sport exhaust kit for the Amazon, although I've only used their 1800 exhaust to date.
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Using the original B18 exhaust valve?
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69 142S Overdrive + 69 164S Manual
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I don't really have an opinion as to whether or not the umbrella seal is as effective as the "normal" seals -- but I sure have seen a lot of umbrella seals hardened like a rock--or missing altogether (having long since been pounded to dust). A hint might be--Volvo switched. That being said, it would really depend on the price of machining. If this isn't your long term motor I'd skip that part--but shaving the head a fair amount will get you a real seat of the pants increase in performance. -- Dave
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+1 on the condition of or lack of the umbrella seals. Replacement a good idea at any point if they have one or three missing. Check for and remove missing bits if you can. If all intact best to leave them. New ones in generic gasket kits can be of poor quality and it's not unusual to find that some have split or gone missing when the cover is off for the first valve adjustment after overhaul. There is considerable difference in the B18 and B20 valve/guide set up. Simply put, B18 guides are long and the valve stems are thin whereas the B20 has short guides and fatter stems. The long B18 guides probably benefit from a little bit of oil, especially the exhaust ones. Machining the B18 guides to take the B20 type seals (there are some Ford silicone + spring types available I believe) might stop this bit of lubrication. Yes you will get a build up of burnt oil carbon on the back of the exhaust valves over time and this does have a bad effect on exhaust gas flow. Just how much would be interesting to know, if a flow bench experiment could be set-up. Racers would be thinning out the backs of the valves anyway so that does show how important that area is.
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Thanks for the info on the umbrella seals. I believe it is not worth the effort/expense of machining the B18 valve guides for a different type of seal. I don't recall them being a problem even if some were missing.
I remember finding bits and pieces of old seals when adjusting the valves on my '65 or '66 122's.
The goal is to just bring my B18D motor up to B18B specs. Maybe with new harden valve seats, just for good measure.
Peter
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