990 Cylinder Head

The place to discuss all matters relating to David Brown Tractors. You will need to register your user name before you can post. If you have already registered could you please make sure that your location details have been completed. Go to My Account in the Main Menu on the left, and then go into "Edit Your Information" and complete your location details. Give the Country (and State/Province if you wish) if outside the U.K. County if within the U.K. Location details helps other members if you need spares, technical advice, or the nearest practical help.

DISCLAIMER -

David Brown Tractor Club Ltd
Forum/website Disclaimer

1. This [forum/website/chat room] and the advice and opinions expressed herein is not a solution for mechanical, electrical, valuations, other problems, breakdowns or issues experienced in relation to the vehicles referenced.

2. If reliance is thought to be placed on any of the information guidance or input provided such information will be expressly confirmed as appropriate to be relied upon.

3. In the absence of any such confirmation no reliance should be suggested or inferred.

4. Members must not disclose information to 3rd parties in anticipation that reliance will be given by non-members.

5. Non-members must not purport to give advice on behalf of David Brown Tractor Club.

6. If you or someone you know is experiencing difficulties or repeated breakdowns you must seek assistance for an appropriately qualified expert who holds themselves out as such.

7. Any comments are free of charge and made or posted on an ex gratia basis. No member or non-member may advertise their professional services

Any user inactive for more than 3 months will automatically be deactivated, please contact admin@dbtc.co.uk if you would like to be reactivated.

Please be aware that your user name and entered location can be seen by all members. We only store information you have entered which is your email address and username, your IP is also stored, we have no access to private passwords.

If you do not agree with your information being stored, please do not register an account, If you wish to unsubscribe at any time please email admin@dbtc.co.uk giving your username.

Amended 27/10/18

Moderators: Segrie61, admin

Post Reply
Moose
Posts: 11
Joined: Sat Oct 19, 2019 5:06 pm
Location: Ireland

990 Cylinder Head

Post by Moose » Sun Jan 12, 2020 7:20 pm

Hi all,

I have acquired a 990 selectamatic with a victor cab. When I got it the engine was weather seized. Having free'd the engine and got the tractor running the next task is to replace the cracked cylinder head (see picture). The current cylinder heads part number is F906760 from what I can make out. The question is will a spare cylinder head part number F921438 be a straight swap when i atempt this repair next week? Also while I head off is there anything else I should look for?
IMG_2306.JPG
IMG_2306.JPG (30.68 KiB) Viewed 648 times
Thanks as always.

User avatar
ollek
Posts: 3924
Joined: Tue Apr 10, 2012 1:20 pm
Location: South West Finland

Re: 990 Cylinder Head

Post by ollek » Mon Jan 13, 2020 5:14 am

There are no part numbers starting with a letter F, all David Brown part numbers starts with the letter K. I think you are reading the casting numbers off the cylinder head, The head number can not be found from the head itself, you need to look in the parts catalogu. Please see the following link https://partstore.caseih.com/us/parts-s ... 6ar1246807 The head is the same in Selectamatic tractors from 1971 to 1976 and models 990, 995, 996, 1210 and 1212, all with AD 4/55 engine

User avatar
GeoffDEAL
Posts: 474
Joined: Tue Jan 27, 2009 8:25 am
Location: New Zealand

Re: 990 Cylinder Head

Post by GeoffDEAL » Mon Jan 13, 2020 7:06 am

Hi be sure to replace the valves original ones have a habit of heads breaking off have had two motors do it but replacement valves have never done it yet, a 1200 head also fits a 1494 no difference.

Moose
Posts: 11
Joined: Sat Oct 19, 2019 5:06 pm
Location: Ireland

Re: 990 Cylinder Head

Post by Moose » Mon Jan 13, 2020 9:15 am

Thanks for the replies. Sorry about the cast numbers. I believe the engine in the 990 is an AD4/49 so the question is will a head from an AD4/55 engine be a straight swap?
Thanks.

User avatar
ollek
Posts: 3924
Joined: Tue Apr 10, 2012 1:20 pm
Location: South West Finland

Re: 990 Cylinder Head

Post by ollek » Mon Jan 13, 2020 10:54 am

Earlier 990:s had a 4/49 engine and later a 4/55 engine. Please check the engine model and serial numbers. There can ber a difference in the connection betwen the water pump and the cylindr gead. A short rubber pipe or a flat O-ring.

Moose
Posts: 11
Joined: Sat Oct 19, 2019 5:06 pm
Location: Ireland

Re: 990 Cylinder Head

Post by Moose » Mon Jan 13, 2020 4:50 pm

I do not have access to the tractor until the weekend but I do know that the serial number is 990A/489166 which suggests it is an early one. I know what you are saying about the water pumps. As seen in the picture above the connection is a short rubber pipe. If I understand correctly I may need to swap the waterpump to one with a flat O ring connection. Thanks for all the help I shall attempt the repair next week.

TEZB
Posts: 285
Joined: Thu Jul 06, 2006 7:37 pm

Re: 990 Cylinder Head

Post by TEZB » Mon Jan 13, 2020 6:27 pm

early 990's had 4/47 engine's latter one's had 4/49 engine's

Scooby
Posts: 3952
Joined: Tue Jan 03, 2006 8:16 pm
Location: Warwickshire

Re: 990 Cylinder Head

Post by Scooby » Mon Jan 13, 2020 8:28 pm

Your tractor went down the track around May-June 1968. If it still has it's original engine it is a 4/47 engine.
Image Image

Three is twee, four does snore, but 6 just clicks........Scooby

Moose
Posts: 11
Joined: Sat Oct 19, 2019 5:06 pm
Location: Ireland

Re: 990 Cylinder Head

Post by Moose » Mon Jan 13, 2020 9:27 pm

Thanks for the feedback guys. I will get some pictures at the weekend and post them.

Moose
Posts: 11
Joined: Sat Oct 19, 2019 5:06 pm
Location: Ireland

Re: 990 Cylinder Head

Post by Moose » Fri Jan 17, 2020 4:58 pm

As promised.
Attachments
CEEB63F4-3704-47E6-8B20-92246AD890C1.jpeg
CEEB63F4-3704-47E6-8B20-92246AD890C1.jpeg (122.25 KiB) Viewed 450 times
1294B15B-B44C-4594-AF4B-E68776B3C235.jpeg
1294B15B-B44C-4594-AF4B-E68776B3C235.jpeg (127.06 KiB) Viewed 450 times

Moose
Posts: 11
Joined: Sat Oct 19, 2019 5:06 pm
Location: Ireland

Re: 990 Cylinder Head

Post by Moose » Sat Jan 18, 2020 2:26 pm

Got a picture of the ‘block’ below the alternator it appears to be blank! Although towards the circle there seems to be two overlapping zeros.
Attachments
AA173EEB-368C-430F-B902-58FB2EBDE477.jpeg
AA173EEB-368C-430F-B902-58FB2EBDE477.jpeg (189.9 KiB) Viewed 401 times

Moose
Posts: 11
Joined: Sat Oct 19, 2019 5:06 pm
Location: Ireland

Re: 990 Cylinder Head

Post by Moose » Wed Jan 22, 2020 5:22 pm

Hi all just thought I would bring this to an end. Have replaced the cylinder head and got the tractor running again. I also had to replace the water pump as stated. I have attached some pictures of the cracked cylinder head. Thanks to all who helped.
Attachments
83E06D37-58D3-40E0-943C-31384E793E47.jpeg
83E06D37-58D3-40E0-943C-31384E793E47.jpeg (126.34 KiB) Viewed 348 times
2F0DB529-B723-4119-B885-3CE760749557.jpeg
2F0DB529-B723-4119-B885-3CE760749557.jpeg (119.25 KiB) Viewed 348 times

User avatar
mc
Posts: 112
Joined: Mon Jan 17, 2011 8:35 pm
Location: Yorkshire

Re: 990 Cylinder Head

Post by mc » Wed Jan 22, 2020 11:20 pm

Interesting photographs.
The original cylinder head, timing case, main frame, oil filler & serial number are correct for a 990 with AD4/47 engine. However the cylinder block has been replaced with a later type as fitted to the AD4/49 (990) & 4/55 (995/6, 1210/12). This would probably explain the lack of an engine serial number stamped into the block. This was the correct replacement as recommended by DB when the supplies of the original AD4/47 cylinder block were used up. If this is the scenario then the engine will be the same cubic capacity as the AD4/55 (100 mm bore x 4-1/2 inch stroke), but retains its original crankshaft, connecting rods & most other components.

User avatar
db2d
Posts: 2172
Joined: Fri Feb 24, 2012 10:01 pm
Location: Monmouthshire

Re: 990 Cylinder Head

Post by db2d » Fri Jan 24, 2020 9:39 pm

When replacing cylinder heads on early 990 and 1200 tractors with the later 962268 assembly new pistons are required because the larger valves may foul the original pistons.

Post Reply

Who is online

Users browsing this forum: Google [Bot] and 17 guests