Bore size on WC engine

[sanborn]

I understand Nascar announced yesterday that there will be NO maximum bore size specified in their rules in 2001. This is good because it should allow the WC (and trucks also) Mopar engines a potential advantage in bore/stroke ratio. The new blocks retain the standard bore spacing and standard 18 head bolt design. Three of the upper inside 1/2" head bolts have been moved slightly to accomodate the WC canted valve head (GM SB2 clone). This should allow the WC engine to use a bore of about 4.220" and a stroke of about 3.150". Based upon piston speed, that should allow race RPM of 9500-9700 and qualifying RPM of close to 10,000. That should ring somebody's bell! The beauty of this decision is it also allows the WC engines to go the other way when they need more torque-to bore/stroke ratios closer to GM/Ford.

[Gary]

Sanborn, you've gotta' stop thinking Chevy when it comes to canted-valve heads! Think 1955-1967 Mopar Poly engines!

[montrose ram]

Maybe getting a little off topic-but Gary, you brought up Poly-head. Is there any way of knowing if Chevy looked at this engine(poly) before designing the porcupine head? And, is'nt it a safe assumption that Chrysler's LA was an attempt to copy the SB Chev.-thus, it killed the Poly? You are not alone in this as Mopar is also claimimg that the NEW Hemi is an evolution of the Poly-head motor.(Mopar Perf. News) But they try to make it look like-and call it-a HEMI. Ya cant have it both ways. Will they be calling the WC motor a Hemi--I dont think so.

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[sanborn]

Look guys, when I put a post on here, it is to inform. Have you ever seen Nascar specifications? They state I & E port centerline heights, cross-sectional areas, valve angles, port CCs, combustion chamber CCs, and general configurations. When they handed the SB2 head to Mopar engineers and said "this is what we will approve" they didn't even know a 55-57 poly head even existed and frankly, didn't care.
And the Mopar engineers they handed the specs and head to weren't even born when the poly head was available. They probably didn't know it existed and they too probably didn't care. Folks, forget about what the marketing department says, this is business.

[Gary]

You guys are missing the point entirely!

Maybe the engineers designing the new Mopar-NASCAR(R) heads are too young to remember the Poly engines, but I'm not, in fact I remember when the Chrysler Grand National entries were running flathead engines. I also remember whining from the competitors when Hudson was winning too many races.

The point I was trying to make is that there are only so many ways to angle valves in a OHV engine, and someone is always going to say that one manufacturer copied another. The Winston Cup rule book was written to accept and validate existing engine designs, not create them. If the Chevy guys are going to say Mopar copied the SB2 engine with a canted valve design, why let them think they discovered canted valves? Explain the facts, and let others decide for themselves. Contrary to what Car Craft and Hot Rod magazines say, God did not create the small block Chevy on the 7th day!

If the Mopar WC engine is a clone of the SB2, why are GM and Ford so concerned with all this whining-foreplay? The basic configuration of any design is not absolute in perfection. Perfection is in attention to the details. OHV engines From Ford will continue to look like OHV engines from Chevy, etc., but the best will be the ones that are built, tested and tweaked to perfection.

It really makes no difference anyway. If Dodge wins too much, they will be penalized aerodynamically or mechanically until they are slower. If they aren't competitive, they will be given more spoiler or a different head design.

Like you said Sanborn, that's business, and that's what will eventually kill NASCAR(R).

[sanborn]

The only thing the GM and Ford camps are concerned (whinning?) about is the bore spacing of a standard Mopar small block. It will allow a larger bore thus shorter stroke which makes the engine more driveable off the turns at many tracks.

[Maxwedge]

Mr Roush was quoted as saying something to the effect that the bigger bore allowed the mopars to use larger valves...that was his concern..his quote is somewhere on car-truck.com..
Maxwedge

[montrose ram]

Sanborn--I dont remember you ever posting anything that was'nt informative, helpful and altruistic(if I may use that .25 word). Some of us like maybe Gary and myself have a hard time comng to terms w/the SB2 issue. We DO have something to cheer about w/ the bore-space news! Thank-you!

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Gary--Not trying to speak for you-but maybe we should let this drama unfold and wait and see what happens. Also, when you look at all the T/F, F/C and Top Alcahol cars running HEMIs with a Pontiac, Chevy, Ford etc. banner across their winshield, I guess 'turn-about is fair-play'!

[This message has been edited by montrose ram (edited September 11, 2000).]