Stroker Crank worth it?

Well I just got my 47 Int PU on the road with a "Stock" 280 CI engine. I also have a 36% OD, 3.73 rear. The truck is no light weight and the acceleration from 20mph in OD is fantastic. All TORQUE & COMPRESSION.280 CUBES?? 3 5/16 +.020 x4 = 279.4 ci.
 
If you have a good Ford crank, it's a lot cheaper to go to an 1/8" overbore (258" vs 255" for the Mercury). Lower piston speed as well. Unless you're starting with complete worn out junk, you'll probably need pistons before a crankshaft. After Gary's (GOSFAST) explanation of the advantages of modern pistons and rings, I think this would be the far cheaper way to get close to 260", and probably give a stronger running engine. I have done 3 - 1/8" overbores on 8BA's and have never run into a problem. My builder said the last one could have gone to 3 3/8" easily.

If you already have the parts you need or unlimited money, please disregard this post.
 
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There's two approaches to this, especially in a light car. The first is the traditional way, which all the posts so far have been about. The second is the way some pretty successful flatties here in New Zealand have gone about it. Keeping the stock 3 3/4" Ford crank, standard overbore, and concentrating on revving higher and producing hp from those high revs. Torque is not so important in a light roadster, so hp at higher revs becomes the goal. I know of several flatties here in NZ that approach it this way. It's not necessarily any cheaper, blueprinting and all the mods needed for this are spendy, it's just a different approach.
In my opinion, unless you particularly want to be period correct, replacing the early trans with a T5 or (in my case) an F150 3+1, is one of the best mods you can make. I can slam through the gears knowing it aint gonna break, and the overdrive makes highway cruising a real pleasure.
 
I do agree that the 258 is a cheaper way to go, also running an EAB head milled for .050" piston to head clearance. I take off .040", but then you have to use a dumore to grind alittle clearance around the edge. The beauty odf this is; There is no need to re balance the assy if you use the original rods and crank shaft. As for poower in the upper RPM rrange, you'd have to run a longer cam which would blead off low rpm torque.
 
I had a friend offer me a 10/10 merc crank which is what brought this whole question on. I ended up purchasing it so that question is answered. I don't want to spin this engine very fast, that just wears out parts. The bottom end on my engine was rebuilt and is a mismatched set so I was planning on getting new rods anyway. Thanks to everyone on the input.

Thanks,

--louis
 
louisb said:
I have a couple of sets of EAB heads I was planning to use. Intake will be an early Fenton super dual with 97s. Cam is still up in the air but I hear good things about the 1007b and I think that will work with stock heads. (Let's not restart the cam debate please lol)

This will be backed up with a stock '39 trans and a 40 rear with 3.75 gears. Should be a fun package in a light A roadster. Sorry if that is to much HAMB related stuff for the Ford Barn.

--louis
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I think you have been given some good advice by most of the folks who have responded. I'm betting if Vic doesn't personally have a Merc 4" crank for you, he probably knows someone in his realm of contacts in Fl who does.
In 2006 I put together a 59, 3-5/16" bore X 4-1/8" stroke, 294ci engine using a SCAT crank. This crankshaft was purchased directly from SCAT supposedly after they had corrected their balance problems. I asked my machine shop guys who did all of my work, to double check the balance on that SCAT crank as soon as it arrived and removed from the box. It was so far out of balance that we were not sure it was usable. They did somehow perform a major miracle and got it within spec. If I had to do it again, I would use the Merc crank I bought back then and still have it today sitting on the shelf collecting dust.
Back to your original question....I would have to repeat the old saying as I was once told..."there is no replacement for displacement"...go for the extra stroke!!
 
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I balanced several of the early SCAT cranks and they were fairly easy to do once I got a simple setup for the mill.
They were light on the counterweight sides for the average bob weight so machining weigh off of the throw side and using a very light reciprocating assembly it all came out fine.
Too bad they all broke 100 feet off the line on the first run.
100% was too much for a cast iron crank.
SCAT advertised they were made of steel. So much for that.
They work great in a street engine though.
 
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