FLATHEAD MERCURY ENGINE BUILD PICS: I picked up some flatheads this summer and am finally getting focussed on building the Mercury (49-53). I pulled the heads off and it looks good inside and has been rebuilt at some time as advertised. I picked up a Dual-carb intake and some Offy heads later. The intake was never used, but the heads had a couple broken fins that I needed to fix. The pics show the build up and then a little shaping. Next is blasting to match the intake. I found and scavenged enough parts to build a complete distributor and two nice Holley 94s. I also built an engine stand that will roll around easily and handle the engine while running. I was detoured a little when I stripped the engine down to ensure the inside of the engine was clean. It had some junk and bugs inside and I am glad I pulled it down to clean. When I pulled the water pumps off I noticed there was one bolt broken off in the black...and then I broke two more on the other side for a total of three broked bolts-Arghhh... the short version goes something like this...drill out bolts...go buy EZ out...heat block with torch...snap off EZ out...break drill trying to get out EZ out...break andther drill...chip end of chisel trying to get EZ out out...Finally I got all three out. Answer to the test- Just keep usuing a larger drill until the entire bolt center is gone and then use a tap to just clean out the rest in pieces- This worked very well and is the only way I would do it again. Scott
Cool, I have a friend with one in his barn but he won't sell it to me. I think he gonna use it in one of his projects, very cool engines.
The one pic in the previous was a check to ensure it was a Mercury with the 4" stroke. Here are the heads.
Won't write a Holley 94 carb rebuild story, but used a few tips from the 94 group to rebuild these for the Offy dual intake. An overnight soak in the carb dip, wire wheel and some high-heat paint for uniformity. Now just need to polish the SS bolts and put them back together. I am expecting a big box from Speedway tomorrow. Scott
Finished up the 94 rebuilds and set them on the Offy intake. I got two Power Valves with the NAPA rebuild kit. One pushes in easy and one is very stiff...any one know the difference and which one I should use for dual carbs? Scott
Do the Napa replacement power valves have a number stamped on. The Holley power valves had a number (vacuum opening in inches of mercury). Stock ones were 7.5 if I remember correctly. You would want 3.5 or 4.5 in each carb for a dual carb set up. I think Vintage Speed carries the different valves.
Got back the Offenhauser heads today from sand blasting (Thanks to my buddy Michael) and they look great. The repaired spots came out fine and they will match the intake nicely. Scott
I am running the same set up. Power valves and all. smooth. I think I am going to take my heads and intake back off. Have them blasted and try that clear ceramic hot coat. Try and keep it clean and shinny. What are You put in the flattie in?
No reason to remove or epoxy up power valves for twin carbs. Ya need em . Just down size the to open at a little lower vacccum. 3.5 would be as small as Id go. If the float level is too high or jets too big you may think it runs semi OK with no PV but thats just cos it running to rich. Maybe with 3 carbs a little more messin with PV will be required. Progressive linkage and you could do away with #1 & 3 PV then.
The question was, "What are you putting the Flatty in?"... I am actually making it into a coffee table for the shop. Here is the stand I just built. It is really low to keep the top of the plexi-glass as low as possible. I will probably have to cut holes for the air cleaners to stick up through. Once everything is together and running I will get the stand and bell housing powder coated black. Some day it may graduate into a hot rod of some type. Scott
I... a coffee table? ... You are fucking with us right? I mean I'll go pick you up something at the thrift store and we can swap if you need a coffee table. I've got the same kinda build up in my 53 Monterey. They are amazing little engines and do great with dual carbs, nice heads and a set of good quality headers. I'm thinking of throwing one of the Isky Max-1 cams in mine real soon. Oddly enough when I tore it apart it already had adjustable lifters installed but everything else was stock. Jack
...It's going to be a really NICE coffee table though...And no...I am not kidding- Thanks for the offer from the thrift shop though- LOL~ Stay tuned... Scott
Here's another one in blue that can run in a stand and you can push it around the garage too. Just think these things look really cool. Scott
The carb kits sold nowadays usually also cover Holley 2110's, which had a "spark control valve" or economizer valve, that looks similar to a PV, mounted on the throttle section. The economizer valve is not interchangeable with a power valve. Look at them closely, they don't look the same.
AlbuqF-1: Your are right about the Power Valve... I thought it was different, but had no idea what it could be because it was super stiff- Good info. GASPIPES: You must be joking...clearly the blue one is an end table and not a coffee table...LOL~ Scott
Nothing like a good cup of coffee and a hot flathead on a cold night! Motor looks great, just keep crankin' the wrenches! And the carbs DO look good.