Charlie Johnson send us this great video showcasing his 1965 Dodge Coronet 440 hardtop. The motor is hogged out to 496ci, with our BIG97 Tri-power on an NOS Offenhauser six-pack intakel Looks and sounds pretty awesome, as you can see.
Thanks to Lou Costabile for making this video. You can watch more on Lou’s Youtube channel, ‘My Car Story’.
Ron House has been a loyal and valuable advocate of Stromberg products for many years. In fact we featured it here waaaaay back in 2012. His beautiful show winning 1950 Merc has been seen up and down the USA. And the Stromberg 97 tri-power has remained 100% reliable throughout that time. Recently, Ron decided to treat his trusty Merc to a variety of updates including swapping the centre 97 of his 3×2 to a BIG97 Primary. We’ll leave the story of the BIG97 Merc to Ron himself…
“In 2010 I made a handshake agreement with KUSTOM KID’S HOT RODS to totally rebuilt my 1950 Mercury Convertible which has been cruising the interstates “WEST” since 1979. The Merc had to be a mild custom circa 1955. It had to be dark green and it must have a FULL HOUSE FLATHEAD V8!!! Anthony Bordonaro (aka THE KUSTOM KID) did accept this total soup to nuts rebuilt assignment but Anthony said one thing right away. NO more 4bbl carb, my new Flattie V8 would now have a Tri-Power Intake Manifold with New Genuine Stromberg 97s. Done Deal, bring on the STROMBERGS!!
THE PERFORMANCE ENGINE SHOP, West Babylon NY got the assignment to build up my 1949-51 8BA block. Builder/owner GARY SHARKEY built and dynoed this Flathead V8 with the following specs; bore 3-5/16, stroke 4-1/4 for cubic inch displacement of 294 CID, 78cc chamber volume into Edelbrock cylinder heads (pn 1116) for compression ratio 8.26 to 1, Isky 88 camshaft.
With Gary building the block it was time to call MIKE GOODMAN at HONEST CHARLEY SPEED SHOP for all the add on accessories; three Regular Stromberg 97s (162 CFM), Edelbrock tri-power intake manifold (325-1109), OTB GEAR Aero Top 2 barrel air cleaners with 3-1/4 filters, MSD Pro-Billet Ready-To-Run Ford Flathead 1949-53 Distributor (8573), Sanderson three tube 1949-53 Ford Flathead V8 Headers (FH-1), Electric fuel pump, Aeromotive Fuel Regulator (13301) with return gas line to gas tank to maintain the required 2.5 PSI max fuel pressure for the Stromberg 97 Carbs.
Mike stated that the Stromberg gas line and linkage was not available at this time. The Kustom Kid worked with Stromberg and in 2010 we received the first prototype Stromberg Progressive Linkage and Fuel Delivery line, 1/4 inch OD stainless tube, CNC bent with furnace brazer connector joints. Nothing but the best from THE GENUINE STROMBERG 97 COMPANY in Tech Support and Needed Parts. “THE CLIVE CONNECTION”
KUSTOM KID’S HOT RODS finished this total rebuilt on my 50 Merc in August 2011. Anthony wanted me to put a thousand mile break in time before I headed west on a two week 2500 miles Road Trip. The last week of September 2011 the new and cool Merc headed to Indiana for the annual James Dean Run and The Duck Tail Run and other car related sites. At the James Dean Run, judging with one hundred other 1949-51 Mercs, my Merc won top prize, MERC OF THE YEAR, aka the 2012 Tee Shirt Merc. Then at the Duck Tail Run, judging with 2500 cars my Merc won Best Mild Custom. Over the next six years my 50 Merc traveled all over the Eastern States racking up 35,699 miles. This Stromberg powered Flathead V8 ran super with “NO” carb issues. In 2015 Anthony re-jetted the center Regular 97 Carb from .045 to .047 jets and added 1/4 inch Phenolic spacers. The Merc always ran good, but Anthony stated the Stromberg’s Regular 97 (162 CFM) was border line lean, running at its max on the Full House Flathead.
Fast forward to 2018 and The Kustom Kid reads about the new Stromberg BIG97 carb in a Rod Magazine’s New Product Department. Anthony tell me this New BIG97 could be what the Hot Rod Doctors ordered for a BIG97 Merc. Reach out to Stromberg and find out if the NEW BIG97 Carb (250 CFM) would be an improvement as a center carburetor on my 294 CID Flathead V8? A quick email to email@example.com and I got all the info on the BIG97 faster then you can say “Jackie Robinson”! Clive’s email states the below mentioned facts on the new BIG97:
The New BIG97 will indeed give your Merc more cruisability on just the center carb
Your Regular 97s would do the job pretty much for everything you need. But they may be a little near their max if you want to REV the Merc to higher RPMs.
The New BIG97 external dimensions are the same as the regular 97 but have some 55% more air flow.
The BIG 97 jetting (.056) will be close, out of the box, but you can check it out and tune it once it’s on the car.
Check out online Tech Section on how to maximize intake flow for the BIG97. Cut away the center web between the two barrels (center carb location on this intake) for intake efficiency which is all about smoothing the passage of the air from carb to cylinders.
Beware. Use the right high flow type air cleaners to avoid cutting down the airflow through these BAD BOYS, THE BIG97.
Clive’s bottom line on this BIG97 center carburetor update for my 294 CID Flathead V8 Merc. “I don’t see a problem with a BIG97 on your Tri-Powered Flathead – the BIG97 Merc.”
The Kustom Kid states, “Say no more. Get what the Doctor ordered! A quick call to Summit Racing and Anthony had The BIG97 in his Shop within two days.
On December 8, 2018 Anthony completeds PROJECT BIG97 Merc. Time for some road testing. My Merc’s Stromberg Tri-Powered Flathead now has a BIG97 (250cfm) for the center carburetor and the other two carbs are regular 97s (150cfm). The below mentioned notes are taken during a couple hundred miles of road testing done during the month of December 2018.
First, the BIG97 started up right out of the box, idle great and also the accelerator pump action was a lot smoother. Yes Sir, the Stromberg gas line and progressive linkage again fit prefect now running the BIG97 with the two regular 97s. The BIG97 is the exact same outside dimensions as the regular 97, but completely redesigned internally.
With the BIG97 now on my Tri-Power intake, Anthony was able to get the timing set at 10 degrees BTC, he also used the blue springs in the MSD Distributor for a quicker advance. The engine was now running with 18 pounds of vacuum. With our 2010 Tri-Power intake using three regular 97s Anthony could only use 6 degrees BTC, silver springs in the MSD Distributor with only 11 pounds of vacuum.
Now it was ROAD TEST TIME!!! After a couple hundred miles this BIG97 update was much more then Anthony and I could ever dreamed!! The BIG97 with more air, fuel and timing advance had the Merc pulling first and second gear right over 3500 RPM, No Problem!! When shifting gears from first to second gear at the new found higher RPM range the dual exhausts are barking and rapping with power. You can hear and feel the big difference the BIG97 provides in power, with RPMs coming quicker and much stronger. Like Clive stated, the BIG97 gave the Merc more cruisability. Yes Sir, at highway speeds, just breathe on the gas pedal and it’s off to the races. Also at lower RPMs in any gear, second, third or overdrive fourth, again lightly touch the gas pedal and the RPMs climb with no problem.
Just for the record, my Stromberg Powered Merc ran Regular 97s since 2011, racking up 35699 miles on them. The Regular 97s ran bullet proof, awesome, no leaks, no ‘oh shits’ and never missed a beat while The Big M was on all its Eastern States Road Trips. Both The Kustom Kid and Clive agree that using the Regular 97 as my Merc’s center carb was little near its max, not enough air-fuel for the 294 CID V8. Both Anthony and I could not believe or ever hope for the major improvement with my Merc’s performance with the BIG97 as the center carburetor.
I really appreciate all the extra work and effort that team The Kustom Kid and The Clive Connection performed on my Merc’s PROJECT BIG97. The Highway’s white lines on Thunder Road will be a lot whiter while cruising my Merc in 2019.
BOTTOM LINE…Always use New Genuine Stromberg 97 Speed Parts made in England, Quality with Modern innovation”.
Norm Schenck at Competition Fuel Systems has been dyno testing Stromberg 97 and BIG97 carburetors for us for year. In fact he had a major hand in developing the BIG97 from scratch.
We set up a dedicated dyno motor at Norm’s facility in Vassar, Michigan and we’ve been watching intently as horsepower has grown with small tweaks to the carburetion and heads. This set up is with the cast iron vortec heads, that Norm ported himself. We have a set of AFR CNC ported heads waiting in the wings and they would probably make more power, but Norm suspects that the limitations of the Edelbrock tri-power intake would not have allowed for much more flow than was achieved with the vortec heads.
Want to know the numbers? This is a GM 330 horse crate motor and the best we got this time (by taking off the mufflers) was 404 ft-lbs of torque at 4300rpm and 386HP at 5400rpm. We still made over 400/380 with the mufflers on. This was on 89 octane gas with top end A/F ratios all in the 13s ! The dyno can now read separate A/F ratios per cylinder.
What this motor will do once someone (ie us) develops a new intake for the BIG97s is anyone’s guess. But it will be impressive, you can be sure of that…
We have been testing our BIG97 carbs recently to see how much cfm we can get out of a modified carburetor, with our consultant Norm Schenck at Competition Fuel Systems in Michigan. The vertical manometer shows the vacuum pulling air through the carb – 20.4″ H2O, which is 1.5″Hg. The handle on the front of the flowbench, below the carb, is set on the 400cfm scale. The inclined manometer shows the volume of air going through the carb as a percentage of that 400cfm scale. In this case, 77% of 400 is 308 cfm. There is a probe inside the 5″ cylinder below the carb, with a small correction factor that makes the airflow correct in term of the Superflow flow calibration plate. Applying that correction factor brings the flow to 300.5 cfm, though what looks like a regular Stromberg 97!!
If you’re planning a big engine build and want some serious cfm capability, contact Norm at Competition Fuel Systems – email firstname.lastname@example.org
Watching a BIG97 equipped Cadillac 331inch race engine (out of an Allard) on the dyno is not something you want to miss. So off we went to Connaught Competition Engines in Kent, UK, to watch and help with jetting and tuning. The way the driver wanted to go was with three BIG97 Primary carbs for this engine, on a direct linkage. The old Edelbrock intake was opened up to take the bigger throttle bores. And the final results? Not bad for an old Cad motor!!
405lb ft torque at 3500rpm and over 350hp at around 5500rpm where these old intakes max out. Best of all, the BIG97 added some 40hp over the regular 97s, even with that old style early intake manifold. We didn’t even have to change the Primary stock jetting (0.56inch main jets). And there were no issues with residual fuel pressure on shutdown, either.
Big thanks to Phil at Connaught Competition Engines for driving the dyno, and Gus Gingell who built the engine.