255 Merucry Dyno Pull
 

Finally got the mercury flathead done!
https://youtu.be/--sgJpT6m7U?si=wI_9ia9iSQLKNmM9

Re: 255 Merucry Dyno Pull
 

couldn't read the results, interested because thats the same motor i have in my 35

Re: 255 Merucry Dyno Pull
 

Speak more clearly and eunciate your words- so many folks slur their speaking. Video and phones do not carry words well generally. Newc

Re: 255 Merucry Dyno Pull
 

Looks to me like the first run had a max of 129 hp and the secong 126.So it's stock, other than the cam? What is the bore now? I had no problem understanding the narative. I think he just has one of them Southern accents. Thanks for posting that.

Re: 255 Merucry Dyno Pull
 

Randall,

That's awesome and thanks for sharing. Can you tell us a little more about what you did? 126 hp is impressive for a stock looking motor.

Re: 255 Merucry Dyno Pull
 

Thank you for posting! So few vids on YT of actual dyno tests of flatheads. Eventually I want mine dynoed. Mine (C59A) is completely stk with only a 0.060 overbore and Pete’s Isky 1007B cam grind. I was thinking mine might come in at around 110-115 hp. Also good to know that the 4,000 rpm tach I have is all the rpm’s I’ll need to measure. Lol!

Re: 255 Merucry Dyno Pull
 

Good job Randall!!!

Re: 255 Merucry Dyno Pull
 

Good job Randal! I had no problem with the accent maybe because we sound alike!

Re: 255 Merucry Dyno Pull
 

I had no problems with the video - understood everything. In looking at Dyno pull #2, the engine is either breaking up due to the ignition or floating the valves at about 3800 RPM. Both torque and HP bounced around and fell right off. Given this is in a stock type application, it is a good running engine.

Re: 255 Merucry Dyno Pull
 

I turned on the captions so I could understand it, good job.

Re: 255 Merucry Dyno Pull
 

Sounded great, thanks Randall. Had no problems with voice or sound watching on my pc with stereo speakers.

Re: 255 Merucry Dyno Pull
 

Nice!!......thanks for posting......sounds great!!.......I understood every word....people say I talk funny too!!........Mark

Re: 255 Merucry Dyno Pull
 

I loved the dyno video. I too wish folks would post more of these. 129hp for a stock engine is pretty good. It should make for a nice cruising car. Good work.

Re: 255 Merucry Dyno Pull
 

Thanks for the video, I enjoyed the dyno pulls. It sounds like a real healthy engine.

Re: 255 Merucry Dyno Pull
 

Not sure WHAT torque number generally run but that is what caught my eye....201.# ft lbs of torque.....that is what you feel in the seat of your pants and under ones foot.

Re: 255 Merucry Dyno Pull
 

I imagine that moves that '46 coupe along quite well! Enjoyed the video Randall. Thanks for sharing.

Re: 255 Merucry Dyno Pull
 

And that's with a 3 bolt carb and intake manifold for a 239 Ford.
If you used a correct Mecury 4 bolt intake and higher flow Holley 885F or 1901 carb, you might have made 140 HP.

Sal

Re: 255 Merucry Dyno Pull
 

It would be interesting to have a little more detailed information, such as the cam grind, overbore (if any), and if any work that was done on the heads.. The early 255's were rated at 110 HP, while the later ones were 125. If this engine is close to stock, those number seem to be right on. It's good to hear, as I was always disappointed with the numbers in JWL's book with a bone stock rebuilt 239.

I agree with Sal about the carburetor, except I'd use a 2G.

Re: 255 Merucry Dyno Pull
 

Yes, Born in Chicago, raised in winsconsim Worked in Ct for 30 years, and have lived in Vermont for the 40 years, you sound perfect to me America,. In JWL's book he used my dyno for the tests. The Dyno was a 300u0 GE electric unit, A UPS weight scale measured the torque output. Using the load cell brackets. The electronics of the unit was too expensive to repair UPS said the scale was a max of +-2%. Max HP from a 239 engine was 78 with out a generator or fan. This seemed kinda low but checking with others found that the Dyno was very accurate in it's load performance.. However after adding a Max# 1 can produced 112 hp.
In recent years I've been to many dyno runs, and know with alittle nudging ,here and there. you can get any amt of hP you want. Just ask any advertising agency
Gramps

Re: 255 Merucry Dyno Pull
 

Glad you all enjoyed , that is the first flathead I have completely rebuilt,it has .080 pistons, stock heads, carb, intake stock size valves with 3 angle valve job and a Isky 817700 cam, springs ,adjustable lifters, I resized rods and replaced wrist pin bushings,
cam ,rod and main bearing, bought ol Rons book and asked Ronnie roadster some questions, thanks for the help!, its a little skidish seeing it come off motor stand and going wide open after warming it up on dyno thinking did I do everything right!