Ram Air 413 Formula
11-30-2011, 12:56 PM
New to the board and just moved to the California High Desert from the Central Valley. Here are a few photos of my 1975 Firebird Formula. The car is taking a kind of 'retro' approach with a mix of some more modern suspension parts. I am using the older 15 X 8" wheels and 255/60R15 rubber that appeals to me from going to stock car and Trans Am races as a kid.
I built the car in my garage and do all the work myself. This is also my daily driver.
The car features PTFB sway bar brace and aluminum subframe bushings, highly modified SPC adjustable upper control arms with Howe tall upper ball joints, with custom made upper bump stop mounts.
The front springs are 500 lbs/in units custom would by Coil Spring Specialties in St. Mary's Kansas. The rear of the car is lowered 1" to bring it dead-level with the front. In the rear, I used 1" billet blocks with 1" steel tube spacers to bridge the gap between the spring plates and axle tube brackets.
a M-20 Muncie is used with the stock 10 bolt with 3.42:1 posi. I was running a 1979 T/A rear disc brake setup, but it stopped no better than my drums, so I went back to rear drum brakes.
I am using a factory Cadillac Seville Disc/Disc master cylinder with DOT 5 fluid and I have super hard pedal with almost no preceptible travel before braking. The front/rear bias is so good I decided not to mess with it, even hard on the brakes at 100+ mph.
The engine shown was the 65,000 mile original Pontiac 350. I stripped the motor to a short block and installed a set of 1966 421 Tri Power heads (9.75:1) and a custom ground Ultradyne camshaft with .466"/.467" - 220°/226° @ .050" - 111.5° LSA. This engine produced 311 RWHP/325 RWTQ on the chassis dyno. Unfortunately, a faulty Mr. Gasket intake gasket caused a vacuum leak to #5 cylinder and damaged a pistion on one of my 570 mile (round trip) commutes to visit family in Northern California.
This week, I am installing my Pontiac 413 (.060" over 400) based on a 1970 4 bolt main block. The short block features a 'N' 3.75" stroke crank, full grooved mains, forged rods, L2262F pistons at zero deck, Canton 6 quart road race pan, Ram Air V oil pump, 5/8" oil pump to block passages, custom-core/custom profile Ultradyne camshaft with .470"/.500" (actual at the valve) - 231°/235° - 110° LSA and Johnson hydrailic lifters.
Heads are 1979 Pontiac 6X-4 castings that flow 240 cfm intake - 215 exhaust @ .600" & 28 in/H20, for an 89% IE ratio. Valves are 5/16' undercut stem 2.11" x 1.77" with Isky #5105 dual springs, screw in studs and guideplates. I ditched the Comp Roller Tips in favor of stock rockers as they fit and patterened much better and kept my net lift within spec.
Ignition is a stock HEI with MSD #8412 low resistance button, 20° mechanical advance curve and 8° vacuum advance. Plugs are R42TS gapped at .060" and used with Delco 8mm wires. Timing is 17° initial, 37° total 45° @ cruise with vacuum advance in play. A custom built (by me) Q-jet works with an Edlebrock performer intake, to save some weight and fit under the fiberglass hood with functional ram air.
That about covers it for now. I am having trouble getting the Canton external dipstick to look right, so it is back out in the shop to fight with that some more.
Hope you enjoy the pics....Robert
5189751898518995190051901
I built the car in my garage and do all the work myself. This is also my daily driver.
The car features PTFB sway bar brace and aluminum subframe bushings, highly modified SPC adjustable upper control arms with Howe tall upper ball joints, with custom made upper bump stop mounts.
The front springs are 500 lbs/in units custom would by Coil Spring Specialties in St. Mary's Kansas. The rear of the car is lowered 1" to bring it dead-level with the front. In the rear, I used 1" billet blocks with 1" steel tube spacers to bridge the gap between the spring plates and axle tube brackets.
a M-20 Muncie is used with the stock 10 bolt with 3.42:1 posi. I was running a 1979 T/A rear disc brake setup, but it stopped no better than my drums, so I went back to rear drum brakes.
I am using a factory Cadillac Seville Disc/Disc master cylinder with DOT 5 fluid and I have super hard pedal with almost no preceptible travel before braking. The front/rear bias is so good I decided not to mess with it, even hard on the brakes at 100+ mph.
The engine shown was the 65,000 mile original Pontiac 350. I stripped the motor to a short block and installed a set of 1966 421 Tri Power heads (9.75:1) and a custom ground Ultradyne camshaft with .466"/.467" - 220°/226° @ .050" - 111.5° LSA. This engine produced 311 RWHP/325 RWTQ on the chassis dyno. Unfortunately, a faulty Mr. Gasket intake gasket caused a vacuum leak to #5 cylinder and damaged a pistion on one of my 570 mile (round trip) commutes to visit family in Northern California.
This week, I am installing my Pontiac 413 (.060" over 400) based on a 1970 4 bolt main block. The short block features a 'N' 3.75" stroke crank, full grooved mains, forged rods, L2262F pistons at zero deck, Canton 6 quart road race pan, Ram Air V oil pump, 5/8" oil pump to block passages, custom-core/custom profile Ultradyne camshaft with .470"/.500" (actual at the valve) - 231°/235° - 110° LSA and Johnson hydrailic lifters.
Heads are 1979 Pontiac 6X-4 castings that flow 240 cfm intake - 215 exhaust @ .600" & 28 in/H20, for an 89% IE ratio. Valves are 5/16' undercut stem 2.11" x 1.77" with Isky #5105 dual springs, screw in studs and guideplates. I ditched the Comp Roller Tips in favor of stock rockers as they fit and patterened much better and kept my net lift within spec.
Ignition is a stock HEI with MSD #8412 low resistance button, 20° mechanical advance curve and 8° vacuum advance. Plugs are R42TS gapped at .060" and used with Delco 8mm wires. Timing is 17° initial, 37° total 45° @ cruise with vacuum advance in play. A custom built (by me) Q-jet works with an Edlebrock performer intake, to save some weight and fit under the fiberglass hood with functional ram air.
That about covers it for now. I am having trouble getting the Canton external dipstick to look right, so it is back out in the shop to fight with that some more.
Hope you enjoy the pics....Robert
5189751898518995190051901