B18A Valve spring seats

sleek lemur · Jan 25th, 2021, 20:39

Valve springs seat on a stepped washer part number 403770, which in turn sits on a flat rubber washer.

I started reassembling the head today after its return from the machine shop but didn't get far. Neither of the parts above are present. Now, when I disassembled the head, I don't remember seeing these. If I had, I would not have chucked them. I called the machine shop, who assure me that any bits that came of my engine were returned to me, and they checked the catch-grid in the bottom of their parts cleaner in case.

Could the washers have come off with the old springs? I don't think so and I would have noticed, I'm sure. Anyway, the springs went to the tip a month ago...

This is a real pain as the stepped washers are no longer available. Brookhouse are searching for some and I have placed a "want" on the forum.

Question is....could the engine have run in the past without these parts? The springs sit in holes in the head and would not have been able to move. I bought the engine as a non-runner and I don't believe the seller had seen it run either.

142 Guy · Jan 25th, 2021, 22:31

I am thinking that there must have been a couple of different arrangements for the valve springs on the B18. The last version (which was used in the B18 which was on the early 140s) is as shown in this diagram from CVI.

Part 5a (415273) is the 'stepped washer' or valve retainer as we on the west side of the Atlantic like to call them. Part 5 are the two collets (415035) or valve keepers which hold the valve retainer compressed down on the spring. The B18 does not have a valve stem seal. Instead it uses a rubber umbrella seal (415424. The 140 parts manual shows the umbrella seal sitting on top of the valve retainer; however, I am sure that I have seen photos of then installed underneath the valve retainer (inside the valve spring).

If you have an older B18 you may have the arrangement of a rubber seal on the very bottom (418515), a lower valve retainer (403770), spring, an upper valve retainer (415273), the valve collets and the rubber mushroom seal on top. The valve springs on these early engines were different (#403717) from the later valve springs used on the late B18 through to the B30.

If you have a later B18 you have the later springs and don't have that bottom rubber seal and the lower retainer. However, it is also possible that you have an early engine that has been retrofitted with the later spring / no lower retainer.

I would have suggested that if you had the original springs you could measure the free length to determine whether you have the new or old arrangement. However, since the springs have now been relegated to the trash heap that is no longer an option. If you have purchased the 418737 valve springs I think you now have committed yourself to using the later arrangement (shown in the CVI diagram). I expect that the 418737 springs will be too long to fit with both a lower and upper retainer.

Given that you don't remember the lower rubber seal or retainer I am going to speculate that you have a later engine or one that has been converted to the later arrangement in which case you do not have to worry about the missing 403770 and the lower rubber washer.

The location of the valve mushroom seal remains a bit of a mystery to me. I will also defer to anybody who has actually taken a B18 apart.

sleek lemur · Jan 25th, 2021, 23:07

That is really interesting, 142. Thank you as always for such a considered response.

My engine is a B18A. I don't know its history and I don't think the previous owner did either. To answer the queries you raised:

1. The new springs I have bought are the 418737, which are the only ones listed at Brookhouse. What you say makes sense. If the springs are the same for B18 and B20, then there's no room for the two piece lower seat.

2. In fact, the only reason I started thinking about the 2 piece lower seat parts was because they are listed in the early P1800 parts book at volvo1800pictures.com., which I had consulted just to make sure I was assembling the thing properly. Your theory that they weren't on my engine in the first place then makes sense.

3. Is this why the part is no longer available? I did find that surprising, given the excellent parts availability for the engine.

Am I "The boy that cried 'wolf'" ?

142 Guy · Jan 26th, 2021, 01:32

The lower retainer, rubber washer and the 403717 spring appear to be available; but, not easily. You have to search through various vendors which includes Volvo Penta dealers. You will likely pay more for shipping than for the parts if you wanted to stick with the original design.

Derek UK · Jan 26th, 2021, 12:59

An old and foggy memory says that the removable seat between the spring and the head was dropped from the set-up very early in the B18 life. Spring just fits direct to the head so you never had these. Basically all of the heads are the same, just skimmed to set the CR. B18 valve gear the same regardless of being B18A, B or D. Big valves came with FI B20 heads.

sleek lemur · Jan 26th, 2021, 16:06

Thanks very much Derek. Just had this confirmed by Brookhouse as well.

Jan 25th, 2021, 20:39	#1
sleek lemur Senior Member Last Online: Dec 29th, 2022 11:47 Join Date: Jun 2019 Location: Thorndon, near Eye, Suffolk, England	B18A Valve spring seats Valve springs seat on a stepped washer part number 403770, which in turn sits on a flat rubber washer. I started reassembling the head today after its return from the machine shop but didn't get far. Neither of the parts above are present. Now, when I disassembled the head, I don't remember seeing these. If I had, I would not have chucked them. I called the machine shop, who assure me that any bits that came of my engine were returned to me, and they checked the catch-grid in the bottom of their parts cleaner in case. Could the washers have come off with the old springs? I don't think so and I would have noticed, I'm sure. Anyway, the springs went to the tip a month ago... This is a real pain as the stepped washers are no longer available. Brookhouse are searching for some and I have placed a "want" on the forum. Question is....could the engine have run in the past without these parts? The springs sit in holes in the head and would not have been able to move. I bought the engine as a non-runner and I don't believe the seller had seen it run either. Last edited by sleek lemur; Jan 25th, 2021 at 20:59.

Jan 25th, 2021, 22:31	#2
142 Guy Master Member Last Online: Today 18:08 Join Date: Jul 2020 Location: Saskatchewan, Canada	I am thinking that there must have been a couple of different arrangements for the valve springs on the B18. The last version (which was used in the B18 which was on the early 140s) is as shown in this diagram from CVI. Part 5a (415273) is the 'stepped washer' or valve retainer as we on the west side of the Atlantic like to call them. Part 5 are the two collets (415035) or valve keepers which hold the valve retainer compressed down on the spring. The B18 does not have a valve stem seal. Instead it uses a rubber umbrella seal (415424. The 140 parts manual shows the umbrella seal sitting on top of the valve retainer; however, I am sure that I have seen photos of then installed underneath the valve retainer (inside the valve spring). If you have an older B18 you may have the arrangement of a rubber seal on the very bottom (418515), a lower valve retainer (403770), spring, an upper valve retainer (415273), the valve collets and the rubber mushroom seal on top. The valve springs on these early engines were different (#403717) from the later valve springs used on the late B18 through to the B30. If you have a later B18 you have the later springs and don't have that bottom rubber seal and the lower retainer. However, it is also possible that you have an early engine that has been retrofitted with the later spring / no lower retainer. I would have suggested that if you had the original springs you could measure the free length to determine whether you have the new or old arrangement. However, since the springs have now been relegated to the trash heap that is no longer an option. If you have purchased the 418737 valve springs I think you now have committed yourself to using the later arrangement (shown in the CVI diagram). I expect that the 418737 springs will be too long to fit with both a lower and upper retainer. Given that you don't remember the lower rubber seal or retainer I am going to speculate that you have a later engine or one that has been converted to the later arrangement in which case you do not have to worry about the missing 403770 and the lower rubber washer. The location of the valve mushroom seal remains a bit of a mystery to me. I will also defer to anybody who has actually taken a B18 apart. Last edited by 142 Guy; Jan 25th, 2021 at 22:36.

Jan 25th, 2021, 23:07	#3
sleek lemur Senior Member Last Online: Dec 29th, 2022 11:47 Join Date: Jun 2019 Location: Thorndon, near Eye, Suffolk, England	That is really interesting, 142. Thank you as always for such a considered response. My engine is a B18A. I don't know its history and I don't think the previous owner did either. To answer the queries you raised: 1. The new springs I have bought are the 418737, which are the only ones listed at Brookhouse. What you say makes sense. If the springs are the same for B18 and B20, then there's no room for the two piece lower seat. 2. In fact, the only reason I started thinking about the 2 piece lower seat parts was because they are listed in the early P1800 parts book at volvo1800pictures.com., which I had consulted just to make sure I was assembling the thing properly. Your theory that they weren't on my engine in the first place then makes sense. 3. Is this why the part is no longer available? I did find that surprising, given the excellent parts availability for the engine. Am I "The boy that cried 'wolf'" ?

Jan 26th, 2021, 01:32	#4
142 Guy Master Member Last Online: Today 18:08 Join Date: Jul 2020 Location: Saskatchewan, Canada	The lower retainer, rubber washer and the 403717 spring appear to be available; but, not easily. You have to search through various vendors which includes Volvo Penta dealers. You will likely pay more for shipping than for the parts if you wanted to stick with the original design.

Jan 26th, 2021, 12:59	#5
Derek UK VOC Member Last Online: Yesterday 17:06 Join Date: Jul 2006 Location: Chatham	An old and foggy memory says that the removable seat between the spring and the head was dropped from the set-up very early in the B18 life. Spring just fits direct to the head so you never had these. Basically all of the heads are the same, just skimmed to set the CR. B18 valve gear the same regardless of being B18A, B or D. Big valves came with FI B20 heads.

Jan 26th, 2021, 16:06	#6
sleek lemur Senior Member Last Online: Dec 29th, 2022 11:47 Join Date: Jun 2019 Location: Thorndon, near Eye, Suffolk, England	Thanks very much Derek. Just had this confirmed by Brookhouse as well.

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