Genesis 427 side oiler

[Anthony]

Originally Posted by olddog

I'm in the process of pulling apart a 95 4.6 DOHC modular. I ...I haven't got it apart enough to measure the bores, but there are no ridge lines at the top. This engine has 105K miles on it. By feel I'm guessing less than 0.010 wear as I cannot feel anything anywhere, and you can still see the hone lines. Here is where it becomes relevant. This is an aluminum block with steel sleeves. I think the steel sleeves hold up much better than cast iron. This is a plus for a modern aluminum FE block, assuming they use steel sleeves rather than cast iron..

I think the sleeves are ductile iron. Although the cast iron of the sixties for the most part may leave alto to be desired, in addition to lighter weight, the real advantage is the ability to repair the block and easily change out a sleeve(s), although you can still sleeve an iron block.

Originally Posted by olddog

Additionally aluminum conducts heat better than cast iron, so cooling and even temps are much improved. However with the aluminum there is much more thermal expansion (think 4 times not sure). In my mind a large aluminum block push-rod engine almost has to have hydraulic lifters. With solids the valves would be mighty loose cold..

Just the opposite, the valve lash is very tight when the engine is cold, about 0.013" for an all aluminum FE. Solids are not a problem.

Originally Posted by Carnut427

Substitute knowledge for technology. Ford (nor the other manufacturers) knew siamesed cylinders would work. To my knowledge, Chevy was the first to do it on the 400 smallblock. Another thought is how much metal must you have minimum around the siamesed bores for the process to work? Ford could have saved a lot of money by making the cylinder walls thicker. They scrapped a lot of 427 blocks because of core shift and the sand used for the casting was so thin between the bores it wouldn't always stay in place.

I think the main reason why auto manufacturers didn't make siamesed cylinders is for even cooling, even expansion, maintaining a concentric cylinder bore for effective ring sealing, i.e.more HP. I would think that with any given engine displacement, it would be better to have an engine designed with cooling around the cylinders than not. As the 427 was made only for NASCAR, for 7 liter displacement limit, as was the subsequent Boss 429, 426 hemi, chevy 427, etc. they designed engines with big enough bore spacing to allow water jackets for an engine of 7 liter displacement. Obviously, with siamesed cylinders, you can take the bore out bigger, compromising cooling which may or may not be an issue.

[Commander]

because of GM's design, the 400 with siamesed cylinders had cooling issues. Steam pockets were created under the deck because there was no flow around the cylinders at that point.

supposedly, that is not an issue with the Genesis blocks.

everyone is implying that siamesed cylinders can be bored to the extreme of a .10 wall shared by two cylinders. Not so.

a siamesed cylinder works better generally because it is thicker overall, stiffer, less prone to distortion.

it IS connected to the next cylinder(s) along a line though. Heat these cylinders up, and constrained as they are by their neighboring cylinders, you'll get out-of-round distortion. bore these connected cylinders and you'll experience MORE of this out-of-round distortion than you would if the cylinders were free 360* around. So siamese cylinders CAN be good, just don't take all that metal as a free pass to bore the daylights out of them or you'll have ring seating (and other) problems like you wouldn't believe.

[Carnut427]

Originally Posted by Commander

...everyone is implying that siamesed cylinders can be bored to the extreme of a .10 wall shared by two cylinders. Not so.

a siamesed cylinder works better generally because it is thicker overall, stiffer, less prone to distortion.

it IS connected to the next cylinder(s) along a line though. Heat these cylinders up, and constrained as they are by their neighboring cylinders, you'll get out-of-round distortion. bore these connected cylinders and you'll experience MORE of this out-of-round distortion than you would if the cylinders were free 360* around. So siamese cylinders CAN be good, just don't take all that metal as a free pass to bore the daylights out of them or you'll have ring seating (and other) problems like you wouldn't believe.

This is the point I was trying to make with my earlier statement "Another thought is how much metal must you have minimum around the siamesed bores for the process to work?". Thanks for explaining what I was trying to say.

Originally Posted by farmallmta

...While various truck and heavy duty engines earlier had used siamesed cylinder design for low RPM applications, the Hudson 308 inline 6cyl developed in the late '40's and first installed in the Hornet line in '51 had siamesed cylinders and was intended to be capable of all-out sustained high RPM racing. This application most closely tracks our interest in this forum and is probably one of the first American applications of cylinder siamesing as we would use it.

The Hudson 308 engine was a bored version of the 262ci engine which required strengthening as the original design limitations were exceeded. The high chromium content of the block alloy minimized cracking of the siamesed cylinders under ordinary use conditions but an overheated block would occasionally crack under severe (race) use. Despite this, the Hornet was THE car to beat in NASCAR (a brutally harsh racing environment in those crude dirt track days) from '51 up into '54. Anyway, the best overhead valve V8-equipped Olds and Mopars found it very difficult to beat the 308ci (FLATHEAD no less) 6 banger in a Hudson Hornet. The other marques (ESPECIALLY Chebby) were completely outclassed and not even close to being serious contenders.

Doc (The Fabulous Hudson Hornet) Hudson sends his kind regards!

THANKS for the history lesson, Doc. While I've certainly heard of the Hudson Hornets and their domination of NASCAR, I saw my first one just a few weeks ago at a local car show. When I came upon it, I first thought it was a '50 Merc, but the side sculpting wasn't exactly the same. Once I got to the engine compartment and saw the dual carbs on the straight six. I realized what I was looking at. Neat car.

Dan

[olddog]

Originally Posted by Anthony

Just the opposite, the valve lash is very tight when the engine is cold, about 0.013" for an all aluminum FE. Solids are not a problem.

For some reason I was remembering the lash gets tighter, as the engine heats. After I wrote that, I kept thinking about the block expanding (growing taller), and I kept coming up with it would be the other way around. It was driving me nuts. Thanks for setting me straight. I feel better now.

I am surprised that running solids in an all aluminum big block engine is not a problem. Again thanks for the info.

I'll have to re-read on the 4.6 modular. I thought it was steel sleeves, but my darn memory is getting so bad I could have that wrong too.