max cam lift???

[slyhog2007]

yes i am building a 360 and am planning on using keith black zero deck clearance pistons http://www.jegs.com/i/Keith+Black/648/KB107.030/10002/-1, with massaged j heads (1.88/1.60), and was wondering exactly what lift could i get away with and if there is any one out there that knows the stock rod lenth for mopar rods i have 3 sets and wondering if they were the 6.123" rods that the pistons require???? this is my first mopar build and want close to 500HP, thanks for the help

 

['64 Cuda]

6.123" is the standard length for a Mopar small block rod. Max lift will be dependent on how much you "massage" your heads & how much piston to valve clearance you have. I think stock heads can go somewhere between .500" & .525" lift. More with the guides cut down & the proper valve springs & valve train mods.

 

[rumblefish360]

Good piston choice.
Have your machinest/head man look at the heads to determin there abilty to handle hi lifts. They also need a spring to handle this lift. It should be the matching spring to the cam.

 

[slyhog2007]

i guess i should have also included that im using stock rockers and i dont know if the springs are stock

 

[Patch]

Not trying to hijack the thread...but what year 360's should i avoid...any??

 

[crackedback]

About .500 lift is max for a stock rocker. Something like that lift, to run max RPM, needs about 300+ pounds over the nose which is where stock rockers start to pop apart.

Safe range is in the .480-.490 area.

 

[70aarcuda]

when the cam is at max lift your pistons are nowhere near the valves...

you have to check the valve to piston clearance during the overlap period....
that is went the exhaust is closing the intake is open...(i think that is order),,the piston is dwelling near tdc (not firing)...

duration...lobe separation...rate of lift per degree...rocker ratio...
all come into play....

only way to know if the cam will work is to check it....

now question is how big on cam are you trying to run????

 

[70aarcuda]

just to give ya idea....

i am building 360 with kb107 .020...the pistons are down in the hole .016...i am using mopar .028 head gaskets....edelbrock magnum heads with hughes 1111 valve springs...

i order the cam last night...engle 253 duration @ .050 with .575 lift....i dont think it will have a probem with it working..

 

[fishy68]

Wait a sec..... Did you say their 1.88 valves and your wanting nearly 500 hp? The small valves do help keep up the port velocity and I'm no head expert but I don't think your going to get all that close to 500 hp with 1.88 valves.

 

[slyhog2007]

Ok I understand that the valves are small, but then again, this is my first engine build by myself. I've done others with dad and everything but this is all mine. Just got done with a 302 sbf swap into a 76' 280z, so now I start my own project on my own money, I'm getting a 70' duster complete with 3 blocks and rotating assemblies, and 2 904 trannys. I ask these things only because I'm young and never built a mopar engine outside the dealership, which only goes as far as short blocks. So I have the know how, its just that I wanna do everything right, thats why I asks about heads and valves, rocker arms, springs, push rod, connecting rods, and cams, because I know these things to be the largest factors in the hp contribution. Maybe 500 is a lil steep for what I have but I am looking for 400-500 hp. Yes I have access to employee pricing on W2 heads, but right now work has been slow so I dont have the budget I had a year ago. I paid $1500 for complete car, 3 engines, 2 trannys, and a sad 8.25 rear end, as far as that goes im looking at a dana 60. Oh i kinda want that loopy idle, i just love that sound.

 

[perfacar]

hi, the 1.88 valve will support 500 hp in a super stock motor. the stock stamped steel rockers will not take much spring pressure or cam! a real 500 hp /360 will not be drivable !! it requires a big cam lots airflow in heads, roller rockers, higher comp ratio to make up for cylinder presure loss of big cam.
the block will need to be squared decked, bored and honed with a deck plate, crank stroke equalized and indexed, and balanced. rods cut for same c.c length, same with pistons, deck hgts have to be all same . and use the lightest rotating mass. l/w pistons, rods, crank. l.t. and narrow metric rings.

 

[fishy68]

Ok I understand that the valves are small, but then again, this is my first engine build by myself. I've done others with dad and everything but this is all mine. Just got done with a 302 sbf swap into a 76' 280z, so now I start my own project on my own money, I'm getting a 70' duster complete with 3 blocks and rotating assemblies, and 2 904 trannys. I ask these things only because I'm young and never built a mopar engine outside the dealership, which only goes as far as short blocks. So I have the know how, its just that I wanna do everything right, thats why I asks about heads and valves, rocker arms, springs, push rod, connecting rods, and cams, because I know these things to be the largest factors in the hp contribution. Maybe 500 is a lil steep for what I have but I am looking for 400-500 hp. Yes I have access to employee pricing on W2 heads, but right now work has been slow so I dont have the budget I had a year ago. I paid $1500 for complete car, 3 engines, 2 trannys, and a sad 8.25 rear end, as far as that goes im looking at a dana 60. Oh i kinda want that loopy idle, i just love that sound.

Understood. I didn't mean to bash you so don't take it that way please. Just pointed out that it's very hard to get 500 hp with 1.88 valves. The heads would have to be done by a professional to support 500 hp. And you don't really need W2 heads although they would be a great asset. (Do they even sell W-2's anymore??) You can get 450-500 hp with iron heads if their prepped right. Only thing is if you can't do the porting and valve job work yourself you'll end up spending more on old iron heads than you would a decent set of aftermarket heads.

Why do you think the 8.25 rearend is "Sad"? It's a great rearend that's way under rated. I've seen them hold up in 12 second A-bodies a long time. You don't need a Dana unless your running real big hp and slicks. In fact all a Dana will do is slow you down in slower cars because it's weighs allot more and takes more hp to spin it. An 8-3/4 is plenty good for 500 hp. Believe me if you build a naturally aspirated 360 that makes 500 hp it'll have plenty of that lopey idle sound you like.

 

[moper]

What kind of budget do you have, and what condition are the engines in?

 

[perfacar]

hi, sorry to lay to rest a myth, the dana 60 is not slower!!! I changed from 8 3/4 to a dana 60, weighed every thing, there was only 32 # difference in total wghts. as for going slower,? car ran exacatly the same E.T. and MPH the car was easier to push besides. few years ago, one of the magizines did an article on that swap. the dana 60, of choice is from a 67-72 1/2 ton ford pickup. its the lightest housing, with passenger car ends.

 

[stroked 340]

Firstoff with what your planing your NOT going to get anywhere near 500h.p. I have never had a 8 1/4 so i can't speak of them but have owned several 8 3/4's and built properly they CAN handle just about anything thats in front of them..as for undestructable dana 60..thats one thing they're NOT,but they do weight more!!!

 

[crackedback]

I agree you likely won't get close to 500hp, especially running stock rocker gear. The cam will be severely limited. You'll need a pretty healthy solid cam at a minimum to get to 500hp. A more realistic number is in the 400-425 range with a good sized nasty duration hydraulic.

Dana - 8.75 arguement. Is a Dana indestructible, of course not. I've seen guys stage cars and roll back, putting slack in the driveline and banging the gears apart. Danas in stock form are about the toughest rear you can run. 8.75 are nice in light cars, under 3300#. Once you get past that weight point, and start beating on them with convertors, transbrakes, 4 speeds, they tend to die at a greater frequency than a Dana. As Perfcar mentioned, my Dana was about 38# heavier than a similarly outfitted 8.75.

I know two guys that run 8's with an 8.75 rr, the cars also weigh in at the 2600# area.

 

[fishy68]

Slyhog sorry about the mis-information about using a Dana. I read a post once where a fellow said he weighed 2 identical size 8-3/4 and Dana units and there was 60 lbs. diff. Maybe his scale was off??? That's what I get for not doing the test myself and taking somebody else's word for it. If I only had a DANA:sad3:

 

[slyhog2007]

im just looking to see what others have to say and imma just looking for the most readily avaliable parts, danas being in jeep s in junkyard being a plus.

 

[Rapid340]

KB pistons have generous valve releifs so I dont think you would have problem with even some of the cams with well over .600 lift

Piston to valve clearance is also effected by duration duration and lobe separation, not just the aggressiveness or lift of the cam.

1) the wider the lobe sep, the more clearance you with have.

2) the smaller the duration, the more clearance you will have.

3) advancing the cam yields more exhaust clearance and less intake clearance. (retarding the cam yields more intake and less exhaust clearance)

Haveing enough exhaust clearance is more critical than intake.

I have seen guys run solid cams that had .020 intake clearance without issues.

You have to be more careful with hydraulics that have alot of lifter preload because of lifter pump up. As always, if your spring pressure isnt enough and the valve goes out of control, valve clearance becomes precious.

 

[perfacar]

hi, dana made four size coconuts, the lightest was for the jeep and the 1/2 ford pickup,67-72, then the b & E mopars, then 3/4 ton pickups, then 1 ton pickups.the jeep and 1/2 ford have passenger car axle ends on them.
as for long life, I have a dana 60 in my 340 duster, 4 speed car, it has 1675 runs on it. 3400 car, leaves wheels up. there is no preload on the clutch when its let out. I have used rag discs and a soft lok clutch .I do not side step ,that breaks parts!!!! mid 11 sec stocker. I use synthetic mobil 1 gear oil.