Early V8 Dyno Work
- Thread starter frnkeore
- Start date
Phil Gillespie
Well-known member
Yes I have had my car on a dyno, 39 standard coupe, to check output and A/F ratio. As a follow up to a previous engine failure due to a detonation problem.
Ended up going up 1 jet size on Main Jet, a single Stromberg 97 carb. Standard 81A engine 83 thou over. Edelbrock Heads. Dont have figures handy.
Phil NZ
Last edited:
TedEaton
Senior Member
I have dyno tested several Ford Flathead V8's. The standard build for a street Flattie will make 150 HP while an all out build (normally aspirated) will break the 200 HP mark. I did dyno a blown Flat Head V8 for an old school dragster that made in excess of 450 HP but that engine was set up on 'Kill'. Ted Eaton.
tubman
Well-known member
I am interested in this as well.
Ronnieroadster
Well-known member
I have had my engines on the rear wheel dyno a number of times however the results must remain a secret. All I can say is more than one HP per cube at the wheels and over 200 MPH on the race surface. Very valuable for getting a good jetting tune up.
Ronnieroadster
Ol' Ron
Well-known member
I doubt that anyone has reached the 200 hp mark with a normally aspirated flathead. using regular gas (91/93 oct). The reason I say this, is: the ports wont pass enough air. They come close but at around 48/6000 RPM depending on displacement, the ports shut dowm. I built a 294 blown engine for Ron Horrell to replace the 296 engine I build 15 years ago. Using a Magnason /Eaton blower his engine produced 235 HP ay 4500 red line. With 5 lbs of boost. It also produced 300 ft /lbs or torque at 3000 rpm with 3 pounds of boost. I would suggest that if anyone makes a new block he work on the intake port allot. Must get rid of the bowl.
A garden hose will only pass so much water, with mother nature pushing on it.
A garden hose will only pass so much water, with mother nature pushing on it.
Ronnieroadster
Well-known member
Lawrie all of the supercharged street Flatheads i build easily see 300 HP at the 276 cubes using modern ideas. Im sure your numbers are pretty accurate possibly maybe a touch conservative. One question would you know the elevation your running the rail at? As you know that makes a difference due to the thin air at higher elevations which will also effect economy but allows for using lower octane gas.
Ronnieroadster
TedEaton
Senior Member
Because the Eaton Balancing website concentrates heavily on the Ford Y-Block builds, other engine builds are not posted on that site. I can see why there's not a lot of engine dyno information out there for the Ford Flat head V8 engines. They are not the easiest engine to get hooked up to an engine dyno so many of the dyno shops out there will not set up for them.
The 450 HP supercharged Flathead was on nitro methane and serious boost. That one made everyone's eyes water as it was running zoomies and the shop was getting a full blast of burnt nitro fuel. It was a solid 9 second runner in the quarter mile.
The 200+HP normally aspirated Flathead was a Bonneville engine that was just breaking the 200 HP mark at 203-205 HP. That particular engine was 294 cubic inches at 10.1:1 compression ratio and was running on 110 octane racing gasoline with a Hogan's sheet metal intake manifold and a pair of 390 cfm 4V Holley carbs. Camshaft was a Potvin 425. The piston design required that the Offenhauser heads be machined accordingly for piston clearance in the cylinder heads. The combustion chamber cc's are 73.6 while the piston domes are 25 cc's. Exhaust header design was also critical on that particular engine. Without looking it up, I vaguely remember it running at 24° total timing for the best horsepower numbers. Tried to post pictures of the pistons and combustion chambers but this site asks for URL links which I don't have.
I'd have to look at the build details for the 150 HP version for the Flattie but remember it having Edelbrock heads, Offenhauser two deuce intake with new Speedway carbs, the small Isky camshaft, and Fenton cast iron headers. Final cubic inch on that one escapes me right now. Compression ratio on that one was for pump gas premium and idled nicely. Higher horsepower versions than this one have been done but those get ragged for running as everyday street engines without a large gain in horsepower. Ted Eaton.