Engine rules?

[88bluestar]

What is your opinion on what can be done power wise with these type of rules?

3000 minimum weight on car.

ENGINE: Must be stock for the make and model except no 400’s or larger small or big blocks. Cast piston only, must use 4 equal valve relief flat top or dish pistons. OEM crankshaft only- cannot be lightened. No aerowing, bullnose, knife edge, undercut or drilling of second or third rod throws. OEM steel Connecting rods only must remain stock OEM length, pressed pins only, weight and shape. No lightening of any parts. Aftermarket water pump, mini starter, pulleys, harmonic balancer and oil pans okay. Aftermarket power-steering pumps okay and must be belt driven. Metric cars may run a 350. NO stroking or de-stroking. Engine height and setback must be in stock location +/- 1”. GM metric frame center of fuel pump must be located a minimum of 1 3⁄4” in front of unaltered cross member. Solid motor and transmission mounts okay. No full midplates. Maximum cranking compression 175lbs. (ignition off, engine turned over 5 times). Oil pans must have at least 1” inspection hole with nothing inside of inspection hole blocking inspection scope from seeing rotating assembly. No alterations to stock oiling system. No vacuum pumps. No turbo or superchargers even if factory equipped.
CAMSHAFT, VALVETRAIN, AND CYLINDER HEADS: Hydraulic cam and flat tappet lifters only. .447 maximum lift at valve or .298 lobe lift at cam. Must maintain 14” of vacuum at 1200 rpm. 1.94 maximum intake valve diameter, 1.50 maximum exhaust valve diameter on Chevrolet engines. No hollow valve stems. Stock size and shape valve springs and retainers. Stock length and diameter pushrods only. Stamped steel 1.5 rockers on Chevy, 1.6 on Ford and Chrysler, NO roller tips. Open chambered heads only, must be unaltered, O.E.M. NO porting, polishing, or gasket matching allowed. The only GM head numbers allowed are 14079267, 3986336, 3986339, 3986339X, 3986388, 3932441, 376445, 3928454, 3932454, 3876487, 3973487, 3973487X, 3973493, 3951598, 468642, 330862, 333882, 3998920, 3998991, 3998993, 3998997, and 3970126. Screw in studs and guide plates ok. 305 engines may use 305 heads (no vortec).
CARBURATION AND FUEL SYSTEM: Cast Holley 4412 -2 barrel only. Must be unaltered. NO screw in air bleeds, NO powder coating, or any modifications. Choke plate may be removed. 4412 must be cast into choke horn of carb. Maximum spacer and adapter 1” combined total with gasket. Fuel pump must be in stock location for make, NO electric pumps or fuel injection even if factory equipped. NO fuel pressure regulators, NO fuel bypass systems, or any cool can devices.
EXHAUST: Stock unaltered cast iron exhaust manifolds only no porting or grinding allowed. No welding exhaust pipe to manifolds or modifying OEM exhaust flanges. No Chevy center dump, Corvette, marine, Lt1 or tubular steel type manifolds. No adaptors between head and manifold must be able to use all OEM exhaust bolt holes in head. No two into one exhaust or x pipes must remain duals.
INTAKE MANIFOLD: Stock OEM unaltered aluminum or cast iron intake only. No aftermarket or stock high performance or high rise. No bowties. No porting, polishing, cutting or gasket matching.
FUEL: Pump or racing gas only. No methanol allowed. No additives or smells. Fuel cell must be secured in trunk any part of fuel cell cannot be forward of any part of rear end. Fuel cell must be visible for inspection purposes from the top through a removable stock appearing trunk lid.


TRANSMISSIONS: Any stock type automatic or cast iron 3 speed OEM manual. No 4 or 5 speed transmissions. Automatics must have stock appearing working 11” torque converter cannot be smaller with ring around it. Scattersheild recommended for automatic transmissions. No aftermarket bellhousings on automatic transmission. No direct drives. Transmission Cooler ok. Manual must have single disc 10.5” clutch, flywheel and pressure plate must be steel, steel bellhousing recommended, minimum 15lb steel flywheel. No mini clutches. Steel drive shafts only must be painted white and have a loop 6” from front u-joint. Torque convertor must be steel.

[tenxal]

The cam, pistons and heads will be the key.

Most cast pistons are short on the compression height. Try to find a quality set that either has 1.535 compression height or deck the block on a shorter piston. A .135 back cut radius faced moly top ring, back cut Napier second and as light a oil ring package as you're comfortable with. I'd go no more than .034 total deck. For heads, a set of the 441's with the PAC 1201X springs and their matching retainers and locks. Angle mill, weld the spark plug cooling holes and get the cc's to 73. For pushrods, a set of Trend .105 wall 5/16" will work great.

Cam lift is the same as the Chevy '151 hydraulic 327-350 horse cam. Get with a cam company that can use this lift on one of their profiles to give the torque you'll need. Mike Jones is who I'd talk with for a cam and lifters.

The oil pan rules are a bit vague. There is power in oil pans...I'll leave it at that.

[ZIGGY]

Typical "factory" or "street" stock CT rules. Agree in general with tenxal though not necessarily with his brand specifics. Can't stress enough if you want to be a winner, you need heads and cam from from someone who knows and cares what they're doing. This eliminates about 90% of typical CT engine builders. Look at people who do winning heads for NHRA stock classes for example. And those who know the gray areas at your track/s. If you wanted to go beyond, IIRC ProPower several years ago was generous enough to let the cat out of the bag for which head casting was most amendable to moving the valves. You could find the post. Best exhaust manifolds and intake with carb position choices are important. And the carb tuned to perfection. Know how tech gauges them. Oxygenated fuel is good, wrong fuel race or otherwise, can lose you power. You've evidently been a racer. You should know you're going looking to stack every single power or weight penny you can find to make dollars.

[Walter R. Malik]

A 60's Q-jet intake with the "R" designation and adapter which puts the carb over the secondary bores.
NHRA "stock eliminator" ring pack.
A camshaft which is spec'ed for venue for where this engine will run
and spend some time finding the best oil pan for power and always keeping the pick-up covered.

Anyone can certainly tell that the rules writers were Chevrolet biased.

[CamKing]

Limited Lift rule cam ( duration depends on RPM range you want to run)
J842HVM Lifters: Limited Travel Hydr Lifters.
JRC15 springs: 1.250" Single Spring w/Damper, 130#@1.750", 347#@1.250", CB 1.150"

[tenxal]

Also, since the rules only specify an "open chamber" head and not a cc value...you can get the 441's down to 67-68 cc's while still having the "open chamber" look.

As well, there are GM cast iron intakes for marine use (not the cast iron Bowtie) that have a significantly better plenum than the early pre-EGR intakes. They are worth the effort to find, believe me. The EGR intake plenum is actually better than the pre-EGR cast intakes.

[Walter R. Malik]

The EGR intake plenum is actually better than the pre-EGR cast intakes.

Being larger does not make it better; especially when the carburetor size is limited.

Ask a seasoned NASCAR CUP racer about this.

That other MARINE iron manifold, (which would probably be illegal, too), is basically a Performer, made of cast iron.

Actually,
the best running iron intake for this application is the 60's Corvette manifold casting 3844459 or 3799349 for the Carter AFB carb.
I believe it came on the 327/300HP engine.

[tenxal]

Being larger does not make it better; especially when the carburetor size is limited.

I didn't say anything about "larger"...just "better". Though it is larger, that's secondary.

That other MARINE iron manifold, (which would probably be illegal, too), is basically a Performer, made of cast iron.

That's not the one(s) I'm referring to (the cast iron Bow Tie casting #14096242).

[Roundybout]

Are there separate rules for Ford? Sounds like if you showed up with one you’d make whoever wrote those rules head spin.

[Walter R. Malik]

Are there separate rules for Ford? Sounds like if you showed up with one you’d make whoever wrote those rules head spin.

OR, a Mopar or even an Olds or AMC.

[rfoll]

Starting around 1990a and later, some trucks came with larger exhaust manifolds. The L31 Vortec motors had them for sure. At a glance they look just like all of the typical small block manifolds, but they are much larger internally and have 2 1/2" outlets.