275 d/r class build ...any suggestions

My drag radial engine is 4.600 bore x 3.750 stroke(was suppose to be 3.850, but signals got crossed). My opinion is to cap the stroke at 4.250 for a drag radial car.

As already mentioned, 18 bolt A-460's are the best choice before you get into the big dollar Thor heads and etc.

how fast are you running with that combo

Still waiting on the E-460 heads to be machined/ported. The chassis at TeamZmotorsports is almost complete. Cylinder head guys seem to have their own time schedule.

Guys,

I am talking about the NMCA Extreme Street class here, and the last time I checked, the FRPP C-460, D-460, E-460, ProFiler 205, Thor and Hemi heads were NOT a legal head option. So I don't want to us to confuse the readers of this thread, by throwing out other cylinder head options.

Thanks, Charlie Evans

Factory head bolt/stud rule? Can only the 10 factory bolt/studs be used extreme street?

The "A" heads ALL have factory head bolt locations.
Some have 8 additional ones but, the ORIGINAL locations are still there and used.

So one could use the additional 8 head bolts/studs to clamp the head down tight and still be inline with the rules?

The .044 nitrous jet limit in the class would allow a pretty serious hit. Will 10 head studs contain it?

1.17 HEADS
HEADS, GENERAL: Xtreme Street is intended for ported, high performance “street/strip and race” cast iron or aftermarket aluminum cylinder heads.
1.17a) HEADS, PERMITTED: Original manufacture, generally available heads, accepted by NMCA, permitted. External modifications prohibited in port area. Spark plug placement and depth must remain stock. Billet or fabricated heads prohibited. Cylinder heads must be overhead valve single spark plug per cylinder design. One-off or custom made cylinder heads prohibited. Internal port areas of cylinder heads may be welded or epoxied, but heads must maintain standard “as produced” valve layout design, valve cant, and valve spacing. (No substituting canted valve for inline head, etc.).
1.17b) HEADS, MASS PRODUCED: Any mass produced, commercially available, NMCA accepted, commonly available, cast aluminum or cast iron cylinder head is permitted. Low volume, one off, aluminum cylinder heads prohibited.
1.17c) HEADS, BOLT PATTERN: Class is only permitted standard OEM bolt pattern for cylinder head bolts and standard OEM bolt pattern for intake manifold. Standard bolt pattern is defined as OEM bolt location & number of bolts. Adapter plates may be utilized on exhaust side that permit modified exhaust header bolt pattern.
1.17d) HEADS, PORTING: Permitted.
1.17e) HEADS, WELDING/EPOXY: Permitted. (See section 1.17a.).
1.17f) HEADS, VALVES: Any OEM or aftermarket valve permitted. Bronze lined or replacement guides permitted. Valve guide location must remain stock.
1.17g) HEADS, MILLING: Angle milling is acceptable. However, approved cylinder heads must maintain (and keep as measured) the original-production engine cylinder head valve angles +/- 3 degrees. Other than the variations listed below, all cylinder heads must measure +/- 3.0 degree of stock original-production engine cylinder head angle. For example, all Small Block Chevrolet cylinder heads, regardless of valve angle from manufacturer, must measure a minimum of 20.0 degree, to a maximum of 26.0 degree valve angle; all Small Block Ford cylinder heads must measure a minimum of 17.0 degree valve angle, to a maximum of 23.0 degree.; all Big Block Chevrolet cylinder heads must maintain a minimum of 23.0 degree intake/14.0 exhaust, to a maximum of 29.0 degree intake/20.0 degree exhaust, etc. The following cylinder heads have slight variations to the above descriptions but are permitted. On these exception heads, valve angle must remain as cast on the approved-version head with +/- 2.0 degree tolerance:
Edelbrock Victor Small Block Ford #77219, 61299, 77289, 77299, 61099, 77099
TFS Twisted Wedge, Standard & ‘R’ Version, Small Block Ford.
Big Block Ford: Trick Flow A460
1.17h) HEADS, PUSHROD SLEEVES: Permitted. Cylinder head may be cut for larger push rods.
1.17i) HEADS, COMBUSTION CHAMBER VOLUME: No regulations limiting combustion chamber volume.
1.17j) HEADS, PORT PLATES/ADAPTER PLATES: Port plates/adapter plates prohibited on intake side of head. Port plates/adapter plates permitted on exhaust side of cylinder head restricted to a maximum thickness of one half inch (0.5”).”
1.17k) Small Block Chevrolet Only: All Pro 23-Degree, Edelbrock 23-Degree Victor, & Pro Top Line 23-Degree Raised Runner & PRO Lightning - Standard Version & Spread Port Versions of Accepted Heads Permitted.
1.17l) ALLOWED CYLINDER HEAD LIST: The following cylinder heads are the only accepted versions for the Xtreme Street class.


Big Block Ford
• Ford Factory OEM Iron & OEM Aluminum (2 bbl. & 4 bbl.)
• Ford 429/460 Aftermarket Cobra Jet Cylinder Heads
• Blue Thunder 460 “OEM Cobra Jet Style” Only. THOR & Other Versions Prohibited.
• Blue Thunder FE #CHFE-(LB-LBOE-SB-SBOE)
• Trick Flow A-460 – PN# TFS-21002, 5441B001, and 5451B001
• Edelbrock Performer RPM 460, Performer RPM 460 CJ, Victor Jr. 460
• Edelbrock FE390-428 (Edelbrock on end) # 60059, # 60069, # 60089, # 60079
• Edelbrock FE390-428 (NHRA on end) # 60057, # 60058, # 60087

How fast are these cars running under these rules?

studly wrote:How fast are these cars running under these rules?

here was the qualifing ladder in oct.


Compulink StarTrak Vortech Xtreme Street Qualifying for 15 entries
Low ET 7.985 4518 Chris Singlenton
Top Speed 171.84 4019 Jamie Stanton
4019 XS '02 Camaro Chev 525 Jamie Stanton Canastota NY 8.085 171.84 171.84
3 XS '86 Mustang Ford 363 Bob Kurgan Byron Il 8.184 169.76 169.76
10 XS '70 Nova Chev 525 Steve Cagle Huntsville Al 8.271 163.61 163.61
4601 XS '99 Trans Am Chev 358 Tim Hendricks Sterlin IL 8.333 168.85 168.85
4005 XS '96 Corvette Chev 399 Bob Curran Bartlett IL 8.345 167.01 167.01
8 XS '68 Firebird Chev 525 Tony Orts Oswego IL 8.416 159.72 159.72
4078 XS '69 Nova Chev 523 Dan Kroll Long Grove IL 8.644 158.71 159.19
4028 XS '04 Mustang Ford 434 Donald Culbertson Brookefield IL 9.074 161.73 161.73
4067 XS '70 Challenger Mopr 474 Andy Mayes Eggleville TN 9.83 143.96 143.96
4442 XS '81 Olds 442 Chev 523 Scott Guiler Salem OH 9.871 163.91 163.91
4142 XS '70 Torino Ford 524 Dave Meister Madison WI 9.89 141.61 141.61
4366 XS '95 Mustang Ford 363 Adam Jude Burns Tn 10.132 90.96 90.96
4177 XS '78 Olds Starfire Olds 403 Bill Trovato Rochester NY 25.587 0 0
4105 XS '69 Camaro Chev 514 Fred Brunn Palm Beach FL 28 0 0
4518 XS '92 Mustang Ford 360 Chris Singlenton Marengo Il DQ 0 0

Bruno,
If those rules were followed and enforced then there wouldn't be a Chevrolet big block out there as the four production intake bolts between the ports on the intake flange are not even there on performance heads. Are all those heads listed on the accepted list...?
The rules say "A"460 heads are accepted as legal yet the intake flange bolt pattern is NOT production and the exhaust valve is 4.5 degrees from stock angle; (10° vs. 14.5° ... their canting is within the rules).
It seems their tech people simply do whatever they want and enforce only what they see fit to police, reguardless of the written rules.

These are just two examples that I can see in the rules you gave but, I am sure there must be others. IF you are allowed to use the A460 heads then I'm sure you are allowed to use their as produced head bolt patten.

By the way, 10 head bolts of 9/16" diameter will hold a LOT of boost or nitrous if it is required to use only the ten.

rules are always made to be bent ........ just depends on how good you are from getting caught .........