Joined: Feb 2021 Posts: 292 Threads: 31
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Location: New Zealand
Car type: Austin 7 Ruby 1938
It would be useful to hear from people who have scrapped the oil baffles at the base of the cylinder bores. Do they think extra oil burning is occurring ? Are they so important when using the pistons with two oil control rings ?
Joined: Aug 2017 Posts: 1,337 Threads: 34
Reputation:
30
Location: Cheshire
Car type: Race Ulster, 1926 Special, 1927 Chummy, 1930 Box
I’ve never used them, or fitted them to any engine I’ve built unless specifically requested.
Alan Fairless
Joined: Mar 2015 Posts: 5,443 Threads: 231
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Location: Scotchland
I have never, ever, used them.
Joined: Jan 2019 Posts: 1,567 Threads: 20
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Location: Bala North Wales
Car type: 1933 RP Standard Saloon
19-04-2023, 10:35 PM
(This post was last modified: 19-04-2023, 10:35 PM by David Stepney.)
When I fitted new pistons to my car (I had a knocking little end) the baffles were still in the crankcase, but they were so battered that once removed, they went in the bin. The new pistons had oil control rings both above and below the gudgeon pin and I have had no problems with oil consumption in the 15 k miles that the engine has done since.
Joined: Feb 2021 Posts: 292 Threads: 31
Reputation:
3
Location: New Zealand
Car type: Austin 7 Ruby 1938
Thanks guys for the comments. You have made my day. It's going to be so much easier refitting block and pistons without using baffles.
I will use a silicon gasket on top of the crankcase and I have been told that I shouldn't get any oil on it while fitting. That would be very tricky if I had to deal with oil baffles and trying to hold block, conrods and pistons hovering over the crankcase and then sorting out the big end caps.
Joined: Aug 2017 Posts: 1,641 Threads: 93
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Location: Monmouthshire
"I usually fit them, just for the fun of it"
Fitting oil baffles for fun, difficult to know what to say! Now, if our crankcases were full of a swirling petrol/air mixture , baffles might be a good idea.
Joined: Oct 2017 Posts: 1,507 Threads: 54
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I've only fitted them on my first engine build 60 years ago and vowed never again.
Joined: Aug 2017 Posts: 3,394 Threads: 106
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Location: Darkest Bedfordshire
Just for variety, I have three pressure-fed three main bearing engines, these have a 1/8" spacer plate between block and crankcase which is slotted about 1" wide to clear the con rods. There might be some difference from the standard set-up, with oil exiting the centre main at about 50 psi. The plate at least partly shields the bores from excessive oiling, and I can't say I've ever had an issue; nor can I say what would happen if I opened up the slots as I've never had any reason to do so. It's a bit of a faff including the spacer in the build but it's quite do-able.
I only have one running two-bearing engine, and like Parazine I didn't see any special reason to leave the baffles out. They are split though so they can be fitted over the con rods. I'm not sure I'll bother with them at next rebuild.
Joined: Aug 2017 Posts: 502 Threads: 13
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Personally I do not ever fit them.
They do not seem to serve any purpose, the pistons and rings that we now use are superior to the originals.