FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: My427stang on October 29, 2017, 12:58:41 PM
-
I posted this on the old forum too so repeat for some guys
Took apart a 1971 360 truck core, never been opened before, stock bearings, seals, and not very many miles. The engine has a 2 barrel intake, C8AE-H head, and 3904V pistons on 360 rods and crank, as delivered by Ford to many truck owners.
I did some measuring and came up with the following
Stock 360 deck clearance - .094
Stock 360 compressed head gasket thickness - .035
Total quench distance - .129
When you combine that with a 72 cc head, 10 cc pistons and 3.5 stroke you get 7.70:1 static compression (and doesn't break 8:1 even with a 68 cc head)
When you combine that with a 256 degree intake lobe, on 112.5 ICL, you get a DCR of 6.34:1
Add that to the two barrel intake, slow ignition curve, bad exhaust manifolds, and low lift cam with poorly flowing stock heads, I am amazed they ran as well as they did! LOL.
It really amazes me, understand what Ford was doing, like everyone, just building reliable work trucks, but a set of nicer exhaust manifolds, a piston that reached the deck and even got to 8.5 or 9:1, and those trucks would have been transformed
-
I am sure it has been talked about a lot , but one more time , what would a good 390-445 ci , tow truck engine compression be ? cam , heads , headers , intake , timing , 4500 rpm max , 5000 pound truck pulling 6000 pound car and trailer . c-6 trans. , 4,10 gears .
-
So that's a wide range of engine choices, but, for a 445 with a 270-ish cam on 106, I'd be between 9.25 and 9.5 static for that application. Likely a good WAG for any of those cammed accordingly
In the 360, I am as surprised (although surprised is a strong word, I always knew, just measuring drove it home) by the compression and more by how deep in the hole, if that 360 was designed to be 8.5:1 and .010 below deck with a set of good exhaust manifolds, it would be an entirely different animal.
FYI, with no other changes but 6.49 rods and a 390 crank, Werby estimated an 80 ft lb increase with a 390 over the low compression 360, what a difference in a "still mild" motor
-
a 390 stroke or the scat stroker crank in a 390 block . no 427 stuff .
-
a 390 stroke or the scat stroker crank in a 390 block . no 427 stuff .
In the end, it really depends on the whole combo, but unless it's undercammed I'd shoot for 9.25:1. FWIW, I run 10:1 in my 445, iron heads, good quench, and more or less a 282S (custom Bullet cam), and it is a real nice combo, but a little too much cam for the range you are looking to run. Less cam would want less compression
-
thanks for the info , I am thinking of putting a tow motor , not a fork lift , together to go into my 1932 one ton ford and get the chevy out , not my doing , was in there when I bought the truck .