That's pretty interesting. Thanks very much.
Oh and for a nice photo manipulating program, go here:
http://www.irfanview.com/
Oh and for a nice photo manipulating program, go here:
http://www.irfanview.com/
PowerWagon896 with your spec i got 291hp@6000 287ft-lb@4500
Looks like a 3200 RPM stal convertor would work pretty well.
Fairly nice TQ @ 3000 (250 ft #s?) & the TQ band builds fat from there & holds well in the upper RPMs..
Running 26" rubber on a 4.56 & shifting @ 6500 RPM...
1st to second shift @ 6500/45 MPH brings RPM down to 3900 to pull 2nd gear
2nd to 3rd shift @ 6500/76 MPH brings RPM down to 4500 RPM to pull out 3rd gear.
6300 RPM is 107 MPH. If the car can pull out 3rd to 6300 RPM, thats a solid high 12s pass.
Here's a handy gear ratio/MPH calculator that I have been using for several years.
http://www.f-body.org/gears/
How about cooking up some HP/TQ numbers for this combo.
241 cu in, 3.505" X 4 175" B/S
12.5:1 Static CR
Same heads
Clifford 95-122 262° @ .050" .595" lift W/1.6 RAR 109° ICL, 109° LSA.
PowerWagon896 with your spec i got 291hp@6000 287ft-lb@4500
I'm think about using 7mm stem metric valves.
I want to stay away from the long stems on the 318 valves & the rocker arm geometry changes involved.
If you are considering a cam with over about .525 valve lift, you just might "NEED" longer valves. The valve guides start to get pretty short, to maintain guide to retainer clearance. To say nothing of valve spring coil bind
If you are considering a cam with over about .525 valve lift, you just might "NEED" longer valves. The valve guides start to get pretty short, to maintain guide to retainer clearance. To say nothing of valve spring coil bind
Valve retainer seats can be deepened on the head casting.
I want to keep as close as possible to the OEM rocker position @ .000" lift of praotical.
I did a CR bump to 13.5 and bump the carb from 600 to an 800 and got 300hp out of both 256 and 262 but 270 went to 290hp, 256 cam would be my choice just has a way better torque curve with very little loss in top end 6000-7000rpm
No problem, the /6 also seems to like wider LSA, i let the program pick best cam specs for peak HP and got 301hp@6000 and basically same torque curve as the 256 cam, the specs it gave was 255/263 @ .050 .595 lift 113 LSA 114.5 ICL (the lift I had to pick and the 262 was used as the base cam) but the other specs the program went through 9000 variations
It seem head flow is limiting factor here the bigger cams make less power across the board except between 6000-7000, Yellow line 256 cam, Maroon line 262 cam, Red line 270, 256 cam 289HP@6000 292ft-lb@4500, 262 cam 291HP@6000 287ft-lb@4500, 270 cam 287HP@6000 275ft-lb@4500-5000
You should go on slantsix.org and look. Doug Dutra....or maybe it was another member.....anyway somebody over there cut a slant head up and they are very thin in that area. It was advised NOT to cut the valve spring seat. But if you decide to, I wish you luck. ...and again keep us posted. I definitely think you're gonna cut a new path with your build.
I did a CR bump to 13.5 and bump the carb from 600 to an 800 and got 300hp out of both 256 and 262 but 270 went to 290hp, 256 cam would be my choice just has a way better torque curve with very little loss in top end 6000-7000rpm
OK, that's good information,
What did you do to accommodate the longer valve stems on your head? Be specific & post dimensional comparisons for the 318 valve Vs the \6 valves & how much you raised/shifted the rocker shaft. (if you don't mind)
Raising/shifting the rocker shaft might help pushrod clearance for the 1.6 rockers.
I will be taking a LOT from the head deck & quite a bit from the block deck to get my quench distance.
Raising the rocker shaft might bring pushrod angles back into a resonable spec.
Bill Dedman, I'll plug your Spec's in when get home from work in the morning, the program does come with a couple dozen turbos but most are Garrett, the intercooler % of cooling has a big effect on power numbers I think go in steps 25% up to 200%, I usually use 100%
Not sure yet. I'm a ways from making tat decision.
I need to go back in the posts.
Who is this Justin that is getting big flow from 1.70" intake valves?
I found it quicker than I thought. Here is what he needed along with the picture explaining the measurement to take. Lemmie tell you, I found this guy SLAM by accident when I was lookin for some hold downs for my 383. He is super to deal with and the quality is outstanding. I'm still gonna get you pics of my head mocked up.
Here's what he said:
"I need:
1. Intake and Exhaust valve lift, minus any lash.
2. Confirmation that your rocker shaft diameter is .875
3. The accurately measured distance between the valve tip and the combination square using the attached photo as a reference. You can hold the square against the valve spring instead of the valve stem. As long as the square is on the same angle as the valve and is resting on the top of the rocker shaft, it will be accurate.
4. The underhead length of your shaft hold down bolts, so I can include the correct length in your kit.
If you have any questions or have trouble properly viewing the photo, let me know and I will respond promptly.
Thanks,
- bbmope65"
no turbo 193hp@4500 266ft-lb@3000
10PSI 343hp@4500 506ft-lb@3000
20PSI 517hp@4000 788ft-lb@3000
I used a garrett GT3071R don't know how close it is to your turbo but there was no 67mm, haven't played with to many turbos with this program so don't know how close this is.