I have read all kinds of information here about the RPM potential of a 225, and it seems that it varies from person to person. I am a very experience V8 and 4 cylinder engine builder, but this is my first go at a slant six. I don't want to re-invent the wheel in hot rodding a 225.
So here is what I am wanting to do, and your advice will be appreciated.

Goal: 500+ HP 400+ ft lbs of torque. Shift at 6000 rpm
Trans. Kessler 5 speed
Diff. 83/4 3.70
TO4 Turbo charger set-up 3 inch pipes, SS tubular header, Clifford intake,BOV etc. 625 Eddlebedlebrockd 8.5:1 pistons
Full top & bottom end stud kit
Ported and flowed head, valve size yet to be determined.
Cam custom ground for application.
Crank, stroked and indexed, and assembly balanced

This will all go in my 69 Valiant signet

_________________
Dr. L Dale Hynes PhD Applied Mechanics

my 11/1 motor was .060 over, 540lift,1.80 int/ 1.60 ex, 750cfm, 3900 stall convertor,i found it loved?? to be shifted at 6500 and was over the line at 6800 at 110mph.my blown 8/1 motor was .080 over, 556lift, 1.78int/1.47ex, 2/ 600 vac secondary,4000 stall convertor, it liked 5500 shifts and over the line at 6000 at 115mph.

- 3.70 will be to much gear. Stay in the 2.76-3.23 range
- 3" exhaust will work. Go 3.5" if you have the room.
- make sure you can mod the edelbrock (and have room to work with it)
- Group buy going on now for better head studs: http://www.slantsix.org/forum/viewtopic.php?t=39144
- Crank, no need for additional stroke
- Turbo66Valiant runs high 10"s shifting at 5500
- I run high 11's shifting at 4650
- I have a PTE 6262 DBB turbo because I'm upgrading the engine. make sure you have room to grow if that is your plan. .63ar on the exhaust
- Clifford intake may be restrictive. The ports were tiny and not much room to open them up. I'm using a heavily ported Clifford and Turbo66valiant is using a hyper pak. I also have a heavily ported Aussie intake.
- Cam=wide LSA 114+

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11.02 @ 120.56
http://www.youtube.com/watch?v=EAxRmoDgsdY
Chassis dyno
http://www.youtube.com/watch?v=wd6hFGzLJMc

Should be an interesting build! Don't forget the fuel system and parachute. Shaker made one mistake - I shift at 5200

Terry - you need less gear
Later
Ryan

_________________
10.74 @ 127.47 mph 1320 ft
6.65 @ 107.80 mph 660 ft

http://www.youtube.com/c/turbo66valiant
Follow on Instagram - turbo66valiant
Facebook - https://www.facebook.com/ryan.peterson.737

Dang! Maybe you trap at 5500? I thought I saw that number in one of your posts somewhere.

At any rate Spudmaster, you can go pretty darn fast without the RPM. 6000 rpm is reasonable for your goals.

_________________
11.02 @ 120.56
http://www.youtube.com/watch?v=EAxRmoDgsdY
Chassis dyno
http://www.youtube.com/watch?v=wd6hFGzLJMc

When I MPH good, it will trap around 5500 but it DONT like it.

_________________
10.74 @ 127.47 mph 1320 ft
6.65 @ 107.80 mph 660 ft

http://www.youtube.com/c/turbo66valiant
Follow on Instagram - turbo66valiant
Facebook - https://www.facebook.com/ryan.peterson.737

Ryan, time for a 2.76 or/and a taller tire.

_________________
11.02 @ 120.56
http://www.youtube.com/watch?v=EAxRmoDgsdY
Chassis dyno
http://www.youtube.com/watch?v=wd6hFGzLJMc

is 488`s with 30in slicks to much???

Thanks everyone for the information. Like I said, I don't want to re-invent the wheel, so to speak. I am surprised that 2.73 to 3.23 would be the gears to use. With my experience in V8 and fours that 3:75 would just be the lower end of the gear ratio range to run for good performance. I will be using a 235/60 15 or a 245/50 15 tire. Won't the high gear ratios kill the "out-of-the-hole" performance with this size of tire? Or does the 225 really put out that kind of torque that low gears are not needed?

_________________
Dr. L Dale Hynes PhD Applied Mechanics

Turbo66valinat manages 1.57 60 foot times with 26x8.5" slicks and a 2.94. I've got a best of 1.79 with 215/75/14 radials and a 2.76. The car leaves harder than when I had the 3.23 and about the same if not a smitch harder with the 2.76 than the 2.94.

The turbo slant makes a lot of TQ.

Turbos work off of load too. Several stick guys start in second to load the turbo.

_________________
11.02 @ 120.56
http://www.youtube.com/watch?v=EAxRmoDgsdY
Chassis dyno
http://www.youtube.com/watch?v=wd6hFGzLJMc

never look at it like that,maybe i could try a 3.91 or 4.56`s ! i do 1.54 to 1.57 60`s on a good hook.