Re: relieving valve pockets
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Here is the link 1954 Hudson
Posted on: 2012/9/15 19:46
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Howard
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Re: relieving valve pockets
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That is a beautiful looking engine, inside and outside.
(o[]o)
Posted on: 2012/9/15 21:48
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Re: relieving valve pockets
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Those are Weber 45DOEC carbs, I cant tell if this is one from the pictures but Clifford use to make them I have recently inquired about them but due to a lack of sales they are not planning on producing more at this time, so unless a lot of Hudson guys get together and preorder them ebay would be about the only place to get one. The header does not look like a Clifford (I have one)but it just might look different on the engine. The relieving looks like the 7X Nasscar style which you can get the exact measurements for online if you wanted to do something similar to a Packard. I have a pair of Solex carbs which are Weber clones essentially (Maybe the other way around) and I was planning on making a manifold for my 327 but there is an issue Weber style carbs are similar to Hilborn fuel injection in the sense that you really need one port to one venturi but the inline Packard engines have simesed intake runners so I don't know if you would get the proper air fuel ratios. If it would work Weber carbs are about as close to direct port injection as you can with a float bowl and are extremely responsive.
Posted on: 2012/9/16 0:48
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Re: relieving valve pockets
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Quote:
Ross wrote:...nice photos of the relieving work around the valve pockets... With all that relieving compression would be affected but see it also has Arias pistons. So they probably have a lump on the crown which partly fills the combustion chamber and together with the "...cast iron 262 head with 1 cut..." gives the quoted approximate 8.5 to 1 compression ratio. My questions are: 1) How big a lump would be likely be required on the pistons? And, 2) Any idea of the cost of a set of pistons like that?
Posted on: 2012/9/16 1:21
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Mal
/o[]o\ ==== ![]() Bowral, Southern Highlands of NSW, Australia "Out of chaos comes order" - Nietzsche. 1938 Eight Touring Sedan - SOLD 1941 One-Twenty Club Coupe - SOLD 1948 Super Eight Limo, chassis RHD - SOLD 1950 Eight Touring Sedan - SOLD What's this? ![]() Put your Packard in the Packard Vehicle Registry! Here's how! Any questions - PM or email me at ozstatman@gmail.com |
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Re: relieving valve pockets
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Not much of one if any actually. Hudson pistons are flat tops and the combustion chamber is over maybe half the piston. You can get a reverse dome piston that puts a popup in that little bit of space if you need to. A Hudson engine with a mildly cut 262 head would get you there with no issue. The pictures of the relief are kinda deceptive in a way a Washington head quarter displaces roughly 1cc so mentally arrange quarters in that space and i would be surprised if it was too much more than 5cc total so you wouldn't lose too much compression.
Posted on: 2012/9/16 1:30
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Re: relieving valve pockets
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The cost kinda varies Arias is not the only show in town but your looking at probably close to a grand on pistons depending if Arias has a blank similar in size I think that a 308 Hudson is like a 3 3/8 bore so you might get lucky.
Posted on: 2012/9/16 1:36
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Re: relieving valve pockets
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Here is a shot of what I often do around the pockets on the flatties--basically a smoothing of the edges in the direction of the cylinder, and a fairly rough cleanup of the biggest bumps and stalagtites in the ports. Seems to make a nice difference.
About those siamesed ports. If you work through the firing order of the L8, each siamesed port ends up drawing for almost a revolution of the crank followed another revolution before they draw again. Don't know how those carbs would react to that irregular pulsation. We need a carb wizard to bring some wisdom here
Posted on: 2012/9/16 6:18
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Re: relieving valve pockets
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Your port work kinda follows Barny Navarro's theory where the air/fuel flow forms kind of a rosebud up and around the head of the valve instead of across the deck i would love to mock up one of these engines or maybe a flat head brigs or something just as disposable to see how it flows on a flow bench with a milled acrylic head to watch the flow. As way of the carbs I don't really know how they would react to that does the L8 fire like right down the line like once the intake of cyl 1 closes the intake of cyl 2 opens? Weber carbs and there variants are notoriously hard to tune and they are designed for one venturi per cyl. I have a friend who races 6cyl Chevy engines and the 292 style engine have simiesed intake ports and i asked hip how they work on a high performance engine and he said that the one port is feeding the 2 cyl one at a time so it may still work. I had even considered making a log manifold and using them just as a side draft carb similar to first gen Vetts and their carters but again there may be a tuning issue. If anyone out here knows someone who deals with European sports cars Triumphs Mercedes Ferrari ect they may have the answers.
Posted on: 2012/9/16 22:30
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Re: relieving valve pockets
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I just want to correct a statement in the last posting. Webers are not hard to tune, in fact it is just the opposite. They are probably the easiest carb to tune because everything is available/removable to tune. The problem is people do not know what to change if they have an issue. I know from experience that you cannot just slap a Weber on a car and have it run perfectly with more power. That also holds true for slapping on a Carter, Holly, Mikuni, or whatever. The difference is that the Weber can be adjusted and the others maybe not.
There are many books on tuning Webers, so research is needed. Because Weber jets are very easy to change it is sort of fun to play with them. Once a Weber is right it is a very reliable carb. That is probably why they were universally copied and used on all race cars until fuel injection took over.
Posted on: 2012/9/17 10:13
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Fred Puhn
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