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I figure ill use 390 rods aftermarket (unless i can find 360's somewhere)
ill have to go with custom pistons i need at least i think 10:1 cr which isnt looking good....(390 rods...360 pistons= 7.57 cr... )
I need good pistons to run a crane 541....or 521 but only if the cr can get up there. Then ill pop for KC stage II's topped with erson's roller rockers, victor intake and a 750 demon.
BTW if all doesnt go well with that...... then im going to cank that and buy a
6-71 from dyers. 7.5 or 8:1 cr perfect forged parts about 10 psi. This 360 will live!!!!!!
any reason why you wouldnt go with a 390 or perhaps bigger to go along with all your other mods, it looks like youll have a great build already but i was just curious. =)
I want the high rpm's... the stroke advantage between the 360 and 390 wasn't even worth the trouble, its like 20-30 max. I wont miss it with over 500hp. Ill make up for it in the gearing and weight reduction. Most importantly because i couldnt bring myself to build the same engines everyone else is running. I just cant see sacrificing my high end HP for some extra torque...considering I'll be running more than most sports cars run anyways.
But anyhow sorry so long winded I just wanna be different and if i can get the CR I want I think it will be a great **** hauler!
I'm not sure how they handle horsepower, but you would be better off staying with the longer 360 rods if you can. In fact, with that small of stroke and custom pistons you could go with a rod in the 7" range! Longer rods would give you more dwell time at the top and bottom of the stroke, which will lead to better cylinder efficiency, and it also reduces sidewall loading of the pistons.
If you are considering KCII's and a victor, then you are friggin' crazy to consider a cam as small as the 521. You will need to feed this thing in order to get the R's up where you want them.
These are my opinions. If I could, I would build a long rod 360 with big cam, heads, and manifold just to see what it would be like.
Well my preferance is the 541.... Thats as big as i have found at the moment in a full roller setup, without being a complete custom grind. The only reason I thought short rods was so i could get a strong aftermarket rod or something. Ive still got some searching to do yet, i need to look into rod configurations as well. Who knows there may be another rod out there that fits.....
There are bigger roller cams. They're mechanical though. Look at the Crane 348801 though 348841. Really humongus cams to get whatever RPM range you want.
Ok Tell me if this can be done....
Ive been thinking about compression and rods and stuff. I dont wanna shell out a grand for custom rods and a grand for custom pistons, so I was thinking all aftermarket of course.....Ill go with 360 pistons and 390 rods on my 360 crank.
that will be:
Pistons=1.776"
rods=6.488
crank throw=1.75" Total=10.014
This gives me a total deck clearance of .156 Wich is BAD.......cr7.57
But I was thinking if i deck the block say .144" it will bring me to a .012 deck clearance which resolves my compression issues and gives me 10:1
So im wondering just how far i can actually deck this block and still clear the valves running that the 541 cam?
Well Ego I dont know? why dont you take some off the deck and , I think you said your going to run KC stage IIs...I know that Edel..claims for every .006" taken off the heads brings you down 1cc.. I cant remember what that works out to on compression? I do know of guys taking as much as .030 off the ed heads..
But you have to watch you valve clearence.. U think they like at least .100"
Russ..
I wish i could figure out how to factor in valve clearance....I know there is a mathmatical solution just like deck clearance. I was thinking i could remove it from the deck like ratsmoker did because i have plenty of it with all that deck clearance...and after pay 2200 for a set of heads im not sure i wanna go cutting them up...lol I may move them to a different motor some day. but removing .144 gave me a 10:1 ratio by the calculator. If not I can atleast make it to what a stock 390 would be and put a dome on the piston. I just know ratsmoker Zero decked his 390 and im trying to figure out how far that might be i guess....
OK. I have to throw a wet blanket on your theory. Make up a combo that brings your piston to 0 deck height some other way. If you take that much meat off of your decks then you will be able to throw a cat between your manifold and your heads! Right idea, wrong execution.
I see three choices:
Stock rods
Custom rods
Crank with 2.200 rod journals, and a BBC rod.
LMAO!! Thats what i thought i was researching chevy rods 2.2 crank pin.... mines 2.5... Is is possible to shave the journals down to 2.2 to throw in bbc rods?
oh yea so whats zero deck? whats it measure too? because if i shave .044" off its .112 which is stock 390 deck clearance.....right....?