You just described my combination.
Any valve train geometry gurus here
- Thread starter Cazman
- Start date
70bigblockdodge
Old Man with a Hat
The valve side sweep should be kept to a minimum. Unless the valve tips are raised significantly in a stock style head(which the 440 source stealth heads are) your geometry should be very close up to about .550 lift, thank you Chrysler engineering. If you go above .550" lift is where the rocker arm will start to really move on the tip of the valve requiring the shaft to move up. I do not think you are there. This is done by machining the shaft mounts off to a flat surface and using blocks that go on the shaft that are taller.
Hope this helps.
I'm assuming on the original heads? Not a issue with new heads so pay it no mind.
This is very Chevy stud type setup. It has no business being followed on a Chrysler shaft mount. High end Chevy's actually switch to mini shaft mount to stabilize the valvetrain. They are talking about where to set the pivot on the stud, then they can measure for pushrod length and keep the adjuster in spec. You need to take a valve tip sweep. As mentioned by Mark V. Using a sharpie or machinist dye you can move valve through its cycle and if you have little to no sweeping across the valve tip, and it is in the center you are golden. It would need raised or lowered to get it in the centered on the tip. If using aftermarket rockers there are different lengths which can affect the location.
Hope this helps.
Cazman
Active Member
Thanks. Yes, I have the 440 Source heads and I sunk those valves. So, this is probably why I am off.
The 440 Source valves needed a valve job to correct bad sealing and I needed some chamber volume, so I sunk the valves .020".
The 440 Source valves needed a valve job to correct bad sealing and I needed some chamber volume, so I sunk the valves .020".
70bigblockdodge
Old Man with a Hat
Very bad to sink wedge valves, they flow best sitting high. What did you do about the spring heights? Guess it is not bad since you have no intention of revving it.
I would not concentrate on getting that pivot higher, start with stock location see what pattern is and work it from there.
I would not concentrate on getting that pivot higher, start with stock location see what pattern is and work it from there.
Cazman
Active Member
My machinist thought we could do .020 without wrecking the flow. It's only got a performer intake and hp exhausts. Low RPM.
70bigblockdodge
Old Man with a Hat
I have listened to the guy from B3 talk at his swap spot, he knows his stuff. However if you are trying to get that much lift with any rocker arm as being shown here.
You really need to machine off the stock stands and mount the shaft in custom blocks that can be located closer or further from the valve as well as taller/higher than the stock location. The valve lifts he is showing is well over .650" that is big numbers and the stock shaft mounts are not designed to work in that area, and will need to be modified greatly to work. Again of you are less than .550" just use the sweep, as long as you are in the center and not wide pattern it will be fine.
K.I.S.S.
You really need to machine off the stock stands and mount the shaft in custom blocks that can be located closer or further from the valve as well as taller/higher than the stock location. The valve lifts he is showing is well over .650" that is big numbers and the stock shaft mounts are not designed to work in that area, and will need to be modified greatly to work. Again of you are less than .550" just use the sweep, as long as you are in the center and not wide pattern it will be fine.
K.I.S.S.
My cam is a bit bigger than .550 and i have no issues with the stock cnc stealths and 440 source shafts and rockers. I do run custom smith brothers pushrods. My cam specs:
Intake Exhaust
@.050 234 244
Lift .573 .563
Like 70bigblockdodge said, KISS
Intake Exhaust
@.050 234 244
Lift .573 .563
Like 70bigblockdodge said, KISS
70bigblockdodge
Old Man with a Hat
I know yours is a roller, both lifters and rockers. I'm looking in around that area at flat tappet solids for my stock stroke 440. Will be interesting to see what my pattern looks like with very milled iron heads.
Of course my car is quite a bit lighter.
What was your compression ratio?
I never bothered to check it. I did not deck the block, and did not measure how far down in the hole the pistons were. I assume its around 10.25:1 but have no factual basis for that. Might be less since i had the heads cnc'd. They also cnc the combustion chambers. I do run pump premium. But cant remember how much timing i have in it.
