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What makes them so much better?
I am just thinking out loud here, but are the cylinder heads that much better because of the xtra width (front to rear)? I would guess you would have more room to work with for your port design.
I know the RY45 Fords are hot right now too, but that is a whole new modular type design, very cool btw. I seen a dyno report from them, wow.
Thanks, Krom.
I think the bigger bore is a benefit. Get huge cubes without massive piston speed from large stroke. Probably some port benefit as well.Quote:
Originally Posted by Kromulous
Like said, it's about bore size. The old STD chevy is 4.400 spacing between cylinders so your limited how large you can get bore wise. Increasing the bore spacing to 4.500 allows almost a 4.25 bore which previously was limited to around 4.185.
You can make a 430 with a 3.75 stroke instead of a 4.0 with a spread bore.
I can confirm that the RY45, do in fact make the power you probably saw on the RY graph on a independent dyno (not RY or Durham's). They are a really nice piece.
Yeah, and what was interesting about that pitch was, i believe it, and i hear alot of guys talk about more HP than that all the time. Especially from some other well known builder, and i just think someone is playing dyno games. Anyway the numbers on that Ford is unreal.
Anyway, anyone got any info on the cylinder heads for the widebores? I see 9, 10, 11 and 13's out there? I know alot of the porting is done by Ultra (Losito) but what are the characteristics of each? I think some builders do there own Clements maybe a few others.
Happy Thanksgiving all.
i think the wide bore evolved from the earlier idea of putting a 3.250 crank in a 400 block in the limited classes , or the 360in or less , some advantages , like mentioned above , were found and it evolved into a new designed open engine.
I could be wrong on this as I really don't follow engines like I used to but:Quote:
Originally Posted by fastford
I believe the RO7 is a spread bore at 4.500 but still only allows for 4.185 bores but the 4.5 spacing allowed for the cylinders to be non siamesed to allow coolant to flow between the bores improving cooling. I think the spread bore stuff became popular to the rest of the industry from NASCAR development and changes in rules to allow them to develop other engines not completely based off old production stock stuff.
Generally speaking with the cylinder head tech and availability over years past, typically an engine with a larger bore and shorter stroke will have a flatter torque curve and carry it out farther allows a lot more RPM to be available and reduces the piston speed. They are usually way more drivable especially in traction limited area's.
Krom, I'm pretty sure Clements does a lot of cylinder heads for several of the other chevy LM engine builders out there. I think ultra pro is more heavily based in drag racing more then circle track but can't say that will 100% confidence.
my understanding was they can go to a 4.250 bore , i bought a bunch of sbc pistons at the Charlotte racers auction year before last that came from cornett that were 4.250 , I assumed they were for the R07 , of course we know what that assume does...lol....
You can get a lot of info on the Yates site.
The FR9 cup engine is the basis for the RY engine... based on a Windsor block and Cleveland heads. They started with a clean sheet but borrowed heavily from those designs.
The heads are cast in Manitowoc, WI iirc and so are aluminum blocks. Not sure about the cup stuff but the same foundry also does iron. This may be old info but was accurate when the FR9 was new.
Ford’s have a very flat and drivable torque curve that builds very smooth power all the way through rpm band. I also think the Windsor firing order helps keeps power applications smoother.
Chevy’s generally speaking (non wide bore) can be a bit peaky and less smooth thre rpm band. Usually going to be better at one end or the other of rpm band. The firing order changes have helped that out a bit, but still room for improvements. Wide bores may have helped smooth that out with bore stroke combos. Not sure. I have never put my foot down on one.
My post is purely speculation. I am not up to date on new style engines. My regular late model days ended in 2004. So I am way out of date.
Not sure if it was by design or just happenstance but:
The RY45 engines lend themselves to reducing power by several means yet still remain less peaky over the Chevy type power-plants commonly used today in LM's. Whether it be a carb, restrictor plate, or timing change, the RY45 stays a lot smoother then your typical Chevy, least to many drivers that have switched from Chevy to the ford.
I don't think you will ever see a Chevy version of the science'd out NASCAR/Top level Ford LM engine just do to shear cost and lets face it, there isn't a ton of late models out there to get enough share of the market to get a return on your investment. Maybe I'm wrong but I just don't see someone investing the time to use the Chevy tech to make a large displacement type engine for the LM's.
A big bore allows larger valves without those valves being shrouded....an engine is an air pump... More in more out.
That RY45 is the deal thou, it make over 850 hp for basically 2000 rpm or so, its insane, and the torque was flat. Thats from the pitch i read its out there somewhere on the Interweb. Someone told me they costs 44K?
Anyone have any experience with the Chevy wide bore heads? just looking for the characteristics of the various offerings.
They make over 900HP and cost way more then that. (Edit: I just realized what you meant on the 2000 RPM, sorry)Quote:
Originally Posted by Kromulous
https://i.imgur.com/3UQlO7F.png
Anyways on the comparable Chevy product: Dyno numbers are going to vary, but there are Chevy stuff out there on par with the ford (least one's I seen numbers on that have dyno'd the ford also. Don't really think you looking much less money for the Chevy when all said and done and the ford's are spin-tron tested (basically no valve train issues) and researched out where unless someone has done extensive testing on thier combo you're likely not going to get the longevity out of it as the basically kit RY45 engine that's being sold. The ford will go more laps compared to the Chevy stuff we ran so in the long run while expensive it's cheaper per lap. Chevy's were averaging 10.00 or so a lap and the ford will be slightly cheaper it seems. But I don't have enough data to say for sure but looking in the 1 to 2 dollar range less per lap.
Before I sound like a ford commercial: I need to say that a lot of the engine stuff is overkill and likely not needed unless racing at the high levels, but it is a highly engineered piece.
I thought it was impressive it made that much power over that extended RPM range. I bet that thing is a task to get hooked up. Usually Dyno numbers on some older Chevys climb to peak and then down, not real flat like the chart above.
Yeah its way out of range for anyone that works for a living LOL ( 9 to 5 er like me) but i still find it interesting. Also the dollar per lap cost average, wow, put 1200 laps on it, your looking at 12k, plus whatever it costs initially.
JustAddDirt , for some reason i cant reply with quote , but i use the 302 firing order on all my ford dirt cams , seems smoother right off the throttle .......
Klik twice...just learned that.
That power curve is as flat as my wallet.Quote:
Originally Posted by Kromulous
i tried that , but for some reason , it would not let me with just his post.Quote:
Originally Posted by Krooser