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Joined: Jan 2016
Posts: 27
Grease Monkey
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Grease Monkey
Joined: Jan 2016
Posts: 27 |
I was told that a Baby Grand Motor circa 1918, has a longer stroke than later 4 cylinder Chevrolet motors, also early race cars preferred this motor to the later motors.
I saw photos of a Baby Grand Motor with a 3 port Oldsmobile head on it. Seems this was a cheap way to get a performance motor without spending a lot of money.
So my question, is there a difference of stroke between the early and late 4 cylinder motors? Anyone have any input???
brasscarguy
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Joined: Oct 2011
Posts: 140
Shade Tree Mechanic
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Shade Tree Mechanic
Joined: Oct 2011
Posts: 140 |
The bigger engine (5.25" stroke) you are referring to was fitted to the series FA etc but was shared with Oldsmobile. This longer stroke engine had a head with three exhaust ports but was not a brilliant design and it seems there was little advantage in the three-port head, even when fitted to the shorter stroke engines. The did look a little more impressive though. I am certain but I am pretty sure the regular Chev 4 shared the same bore and stroke throughout production.
Regards
Al
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Joined: Oct 2011
Posts: 140
Shade Tree Mechanic
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Shade Tree Mechanic
Joined: Oct 2011
Posts: 140 |
The bigger engine (5.25" stroke) you are referring to was fitted to the series FA etc but was shared with Oldsmobile. This longer stroke engine had a head with three exhaust ports but was not a brilliant design and it seems there was little advantage in the three-port head, even when fitted to the shorter stroke engines. The did look a little more impressive though. I am not certain but I am pretty sure the regular Chev 4 shared the same bore and stroke throughout production.
Regards
Al Corrected and word "not" added to last sentence
Last edited by AlBrass; 03/12/16 04:00 PM.
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Joined: Nov 2001
Posts: 19,758 Likes: 64
ChatMaster - 15,000
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ChatMaster - 15,000
Joined: Nov 2001
Posts: 19,758 Likes: 64 |
The bore is the same but the stroke is different. As an example the 490 has a shorter stroke than the FA & FB engines. After 1922 (last year of 490) the stroke was the same for the 4 bangers.
How Sweet the roar of a Chevy four!
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Joined: Oct 2011
Posts: 140
Shade Tree Mechanic
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Shade Tree Mechanic
Joined: Oct 2011
Posts: 140 |
Hi Cipper,
Pretty much what I said but I think the Baby Grand/Royal Mail had the shorter stroke engine too.
Regards
Al
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Joined: Nov 2001
Posts: 19,758 Likes: 64
ChatMaster - 15,000
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ChatMaster - 15,000
Joined: Nov 2001
Posts: 19,758 Likes: 64 |
The Royal Mail and Baby Grand model names were used from ca 1914 to 1922. That included the Model H, F as well as FA and FB. So the engine changes during that period would be included if you refer to RM or BG models. BTW, the 490 was introduced in 1916 and continued to 1922.
How Sweet the roar of a Chevy four!
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