I did not want to clutter up the report on the awesome, class winning and ass kicking Y blocks - so I started another thread. Jay - move this as you see fit. I wrote some stuff on this one a while back, but felt that it deserved a proper summary in a single document. It was an interesting build, and since the folks at Hot Rod are not likely to do an article on it - I thought I should document things before they are forgotten/lost. Some of this will be repetitive, please forgive and understand...I have added pictures
. Sorry – but this is a really long post. Daylight saving time and I am up extra early…
This year's EMC was broken into five classes. The FE ran in "Spec Big Block". This class mandated Edelbrock 60059 heads and an RPM or Victor intake with no welding or epoxy. Comp Cams camshaft and hydraulic roller lifters. MSD ignition. Sheet metal catalog offered oil pan, bolt on rockers. Headers need to be passenger car catalog items. Carb mandated to be a 4150 flange four barrel with 1.750 bores maximum bolted directly to the intake - no spacers. Crank driven water pump, 11.5:1 compression. Cubic inches are set at 470 maximum with no factoring - add up average horsepower and average torque from 3500 to 6500 RPM to get a score.
This entry was mostly the work of William Blair - my shop's lead machinist. I provided him with parts, guidance, and did the tuning. He did all the machining and the majority of the assembly work and deserves the credit for his efforts.
We built a 468 inch engine using last year's block - a filled 4.250 bore Sideoiler Garage development part. The crank is a 4.125 stroke Scat forging. Pistons were Diamond, with .043 rings and lateral gas ports. They were originally spec'd for a 4.250 stroke build and were altered to work with this one by milling some off the top, and running an .066 Cometic 4.250 bore head gasket along with a 6.8 Scat rod. Combination put the piston .020 out of the deck. It seemed to work pretty well and used a lot of pre-existing parts. It’s an unusual approach but not really exotic. It might have helped a little bit by reducing crevice volume above the top ring.
The rules mandate a minimum .043 top and second and a 3.0mm oil. We started out with normal Total Seal classic stuff (I don’t do gapless) and then reduced the radial wall thickness. Going by memory I think we have the second down to +/-.130ish – maybe smaller.
We ran T&D street bolt on rockers with the normal 1.75:1 ratio. For the Edelbrock heads we decided to use our normal CNC program, which was designed around a 2.200 intake valve. The rules mandated we run the valve sizes Edelbrock ships with their completed heads. Our 2.09 valves were just barely able to carry a seat in that port bowl – they sorta “hang” in there – not ideal but it allows us to re-purpose the heads later on by installing proper 11/32 guides and the bigger valves. The smaller valves really crushed the flow though – we had 304@.700, which is 20 cfm less than we see with the larger valves. Airflow translates to horsepower and it showed in the event – BB Chevy entries got to run 11/32 stem 2.19 intake and they finished 1-2.
Intake is a Performer RPM with nothing beyond a good port match blended +/- 3” into the runners. In retrospect I should have made a removable divider – but I just bolted the carb down and started tuning. Carburetor is an 850 vacuum secondary Holley with the rear barrels tied up to open - - just worked better on dyno this way. It is a 1990’s reissue of the original L88 carb with Ford kickdown linkage added. I acquired when I worked at Holley way back then. It still has the choke tower and blade intact.
In an effort to get valvetrain weight down I opted for the newest conical valve springs from Comp along with a minuscule titanium retainer. We were running at .070ish from bind and 175 pounds seat pressure – right on the design limits for that package.
Cam is required to be a Comp hydraulic roller piece, but can be custom ground. Our’s is 241/243 @ .050, .696/.670 lift on 106 LSA – installed at 101. The rules mandated Comp hydraulic roller lifters were a real challenge. Comp does not make a short travel hydraulic roller for the FE. When we first tried to just run them we could not get a clean pull to the 6500 RPM target no matter where they were adjusted to. I looked at the rules and saw nothing about modification to the lifters – so I had Willy make up some little sleeves to pack between the retaining clip and the inner plunger, reduced our travel to +/- .020 and were able to pull cleanly from that point on.
he valve rules were going to really hurt our combination so I decided go for the “cool factor”. I chose to run a +/-1968 Ford C8AX oil pan (after getting “permission” since it has not been in a catalog for a few weeks now…). Rod C from our forum lent set of 1-7/8 primary Hooker headers for a ’63-34 Galaxie which turned out to be my best set. He also lent me a pair of cast iron long tube manifolds to try. To finish off the old school vibe I ran a pair of chrome “Power by Ford” valve covers. In a sea of modernized big block engines the old FE looked pretty darn cool – like it just got plucked from a 1970s street racer except for the alloy heads.
Early on in the contest some folks had some issues with the just upgraded dyno software at the school where the contest is held. By the time I ran things seemed to have been sorted out – all of my pulls were straightforward with no drama. My best score at home was 1109 and I was targeting 1160. At the school we made four pulls with the headers and got a best average of 1150.1. Peak horsepower was up +/-4% - 25HP from home. Some of the difference is fuel – we tested on 93 octane Citgo, while the actual contest fuel is VP100. The exhaust on the school dyno is also straight out the back and open while mine has an immediate 90 degree turn and goes up through a pair of large mufflers. Our score put us in the middle of the pack - half the entries were all bunched up within 13 point spread. The two BB Chevies were way out ahead.
After making the score pulls and seeing that were indeed well behind the leaders I decided to use our remaining time to swap to the unmodified ’63 Galaxie long tube cast manifolds and make a couple pulls in front of the media. The swap was quick - thanks to Willy and Tim – and we were rewarded with the expected lower overall score but nearly the exact same peak horsepower 622 versus the previous 623. Not too damn bad for old cast iron with 2.5” outlets.
In closing – we made over 600 horsepower with Hot Rod photographing and recording video, on a third party dyno. We used 11.5:1 compression, a dual plane intake, a 48 year old carb design with choke, a pair of 53 year old exhaust manifolds, and a 48 year old oil pan and valve covers (repro). All the latest stuff for sure.
Lots of pictures, a couple of charts, and a video link follow. I am first providing the data from my “home” pulls since its more conservative and I can defend the numbers. Home background data was 28.58 baro, 40% humidity, 69 degree cell inlet air and a DTS calculated correction of 1.066. I will try to add the contest data later on.
Video link
https://youtu.be/mRDbjp6096E
