7120/0630 Head Flow Chart

[jsawduste]

Way back when PhotoBucket was still around there was a couple pages that showed flow ratings for 7120`s and 0630`s. This was way back in 2008 ish.

Has anyone have a link or info they could share on what these heads flow ?

An added bonus would be stock vs. a big valve head.

Dino ? Russ ?

[jsawduste]

Been running the HS 1.6 rollers.
Been sitting on a set of HS 1.7`s and am wondering if the extra ~.30 of valve lift is even worth doing ?

IIRC the difference between say .450 and .500 was marginal on both the intake and exhaust. On a 7120 with stock sized valves but short side cleaned up and the bowls done. Gasket match of course.

[Tolemar]

There is some info in here. viewtopic.php?t=3028

[Cheromaniac]

Way back when PhotoBucket was still around there was a couple pages that showed flow ratings for 7120`s and 0630`s. This was way back in 2008 ish.

Has anyone have a link or info they could share on what these heads flow ?

An added bonus would be stock vs. a big valve head.

Dino ? Russ ?

Here ya go. Scroll down this page:

http://jeep4.0performance.4mg.com/custom3.html

[jsawduste]

Thanks for the replies Tolemar and Dino for the leads.

As it stands the little extra lift with the 1.7`s isn't worth the time and effort. If I want to make any improvements it will be a further reworked head and a increase in the static compression. The engine runs great now and pulls like a freight train from below idle up. ~ 2800 it gets on the cam starts to pull pretty hard.

Think I`ll just leave it alone and run it.

[Cheromaniac]

What parts do you have in your engine?
There's indeed little advantage to going from 1.6 to 1.7 ratio rockers unless the head has been ported in order to see any benefit from the 0.025-0.030" extra valve lift.
What supporting mods (cold air intake, larger TB, header, exhaust) do you have? There may be room for improvement in those areas as well.

[jsawduste]

Dino, I`m at about all there is for what I want to use the engine for.

9.8 static with a 216 @.050 cam creates about all the combustion pressure that engine will take without getting to close to detonation.

Eagle rodded with the 12 cwt crank and fore mentioned modified 7120 head. 63mm on a late model and a set of Doug Throleys with a 3" collector. I changed it to OBD2/JTEC and Chris Jensen did the tune. The IAT is in the CAI and Chris set the tune to reflect having moved the crank sensor to bump a few degrees of timing in.

You recall the dyno runs from a few years back ? That was still OBD1 without the IAT and crank Sensor. The engine ran pretty well at that point.

Yes I could go to a big valve head but I`m not too keen the ROI would be worth it.

I`ve had the 1.7`s sitting in the package for a long time. Idle thoughts were is see if it was worth the time and trouble to install them.

Have a couple blocks, heads and 12 cwt cranks here. Could reuse the Eagles or snag a set of rods from Russ. Maybe build another engine with the 1.7`s and a big valve head around a different cam ?

[Cheromaniac]

Sounds like your engine is pretty much maxed out. You could go to a 68 or even a 70mm TB and enlarge the intake manifold plenum opening to match but that's about it.

You do have the parts to build another engine and that would be cool but if you're happy with your existing engine, why bother (unless you buy another Jeep to start a new project )?

[Russ Pottenger]

John,

I think you should start transferring large amounts of money over to me so we could start a completely new stroker build.
; )

.... As Dino Pointed out and I’m sure you probably agree that Your existing combination is doing just fine and most likely wouldn’t be picking up that much more to justify the expense.

It’s in your DNA to tinker and make things better, but I think your existing set up is pretty well thought out and serving you well
my friend.

[jsawduste]

LOL Russ, you know me well. Poor Jeep always seems to be always in a state of flux. Think there might be as much or even more playing with it than driving.

Hopefully it never ends. :mrgreen:

[Tolemar]

Turbo or supercharge that bitch! That's what I would of done if it wasn't for smog concerns. Ive been researching how to program it with my hp tuner bigger injectors and a 2 bar map sensor. Might have to pull pistons out and mill the dish out a bit to bring the compression down since you have high dynamic compression allready and a iron head. But you can atleast get about 50% more hp and torque compared to what you have now.

[Brianj5600]

Did you try the sticky just above?

[jsawduste]

Followed the link from Tolmar and Dino if that's what you mean.

Thanks

[Brianj5600]

A sticky is a thread that is permanently at the top of a forum or sub forum for easy access.

viewtopic.php?f=5&t=226

[jsawduste]

That is an old thread by a respected member. Problem is the attachments have long been expired.