Yes, sort of. My plan is to get the engine up and running with the stock manifolds initially. Then once it is tuned, I'll have to use a dyno for fine tuning, this will give me a base line. I will then make a new plenum an exact copy out of fiberglass just much larger, dyno it again to fine tune. This will give some data that I can share.

 

Thanks WarJohn !
every time I do the math on here I take the heat!
looks very nice and like the torque curve of the Z06 vette I drove..
hard not to light up the tires... like you said a 2.88 might be in order...


I am on the look out now for a used 6.0 and transmission

 

If I were you I would use the 4L60/700R4 not the 4L80. The 4L60 is much lighter and has less parasitic loss. There are loads of hipo mods to beef up the 700 to take the torque of the bigger engine.

BTW I know Norm has some TWR long throw cranks on his shelf.

 

that is great
so buy one of those easy to find street fighter TCI 700R4 ok...
and I am saving, putting money in the bank, because I know it have to pay for the upgrade. <grin>

 

i was going to mention that the 700 is 28lbs lighter than the 400 trans, with out the converter.

and mine has a light weight converter, 12"dia. down to 10" dia, less rotating weight!

as always, weight is the enemy when related to performance!

engine torque will be what it comes out to be??

torque at the tires is what gives exciting performances! so i'm not so sure of the 2.88 as a performance gear!

 

With the 5.3L the 3.58 I have wakes the car up and made it much more lively. I am concerned that with the 520ftlb's torque of the 6.7L I will have major traction issues with the short diff. Also I live in the country and all my driving is open road. no traffic lights for 40miles

 

one of my hi-performance cars was a 1982 Camaro that i built a BBC Chevy, 502 cu.in.(8.1L), torque was close to 600 lbs.ft. dynod. 3.55 gear.

new owner put in a 3.07, car just did not feel or drive the same, with any spirit or excitement!

Jeez, 2.88 and overdrive with enough torque and 6500/6700rpm will put you over 200mph, you will be into some serious Aerodynamic situations!

you may need wings.LOL,HE He.

OH he$l go for it, (Full speed ahead and damn the torpedoes).

 

I decided it was a good idea to undercut the valve stems about 0.030". These are the old valves I was experimenting on to get the process refined before I dive into my new SS valves.

Before


After

 

lookin good warrjon!

of interest , some guys are trying a 30* seat angle inlet , with a slight 20* just below the actual seat,(check out some info of the valve window supposedly is larger at the same lift as a 45* seat).donno.

and i have recently been against a 50* seat for exhaust valve, some say under hard use and hi seat heat can actually pull the seat loose, because of valve deforming is sinking and stick to seat.

that is a sobering thought, and has some logic to it!

SOME THINKING ABOUT THE HE DROPPING SEATS COULD BE RELATED TO THAT VERY THING, SUPER HOT EXHAUST VALVE STICKING TO THE SEAT(welding)AND WHEN OPENING PULLS THE SEAT LOOSE!!

ron

 

Yep we will have a multi angle seats, the cutters these days cut all 3 or 4 angles in 1 pass.

Did some testing today with the undercut valve and it made NO difference to flow, so I chucked the valve up in the lathe and cut a sharper radius on the back of the valve as this is supposed to improve low lift flow, NOPE no increase in flow, only benefit I saw was lighter valve.


Stock on the left

 

are you saying that all the mods and tests ,may be a waste of time?, no flow increase?
along with no proof that light valves have any benefit?

i was in the performance engine business for over 50yrs. i became aware modifying of valve and port systems back in the early 1950s. seen many mods come and go, some times things cant be explained by theory or logic, but do work anyway! i had many types of engine rebuilding machinery,including a good seat and guide setup with some good multiangle cutters, and also some custom ground NO angle radius curved cutters!

i have oversized valves in my V12 , all work performed myself to my own logic and ideas, it runs fine no problems.

a quick excerpt from the designers of the Jaguar V12 engine, that you cannot always take static flow results as perfect source for more effcient torque and HP.

 

how tall are those valves and what is the stem dia.?

 

No I'm not say it was a waste of time, I am just reporting what I have found. I did not test the heads before I ported them. I do have a stock head that Norm gave me to test so I can get a base line.

Back cutting the valve stems and head might work in a Chevy where the port has a much tighter turn into the cylinder but is does not increase flow in a Jaguar V12 head. I think this is because the port is a lot straighter than the Chevy.

Lightening valves is a completely separate benefit from flow, and I will be lightening all the valves including adding a radius to the Exhaust valve margin. The new exhaust valves have a square edge.

I realise there is a difference between static flow and the dynamic flow of a running engine, but if you think about it when the valve opens flow is static for a short period of time while the valve is open. What I am trying to achieve is to optimise the intake to extract as much torque as possible from the stock valve train.

 

They are stock HE valves stem diam is 0.3093"

I have not measured the length but are the same as the ones removed side by side.

 

.

johnathon, we in the states call it 5/16" stem diameter.

 

my experience is light weight valves show no difference over stock unless you are going to higher revs than stock, and with factory stock springs!

most pre engines(in good condition can rev 6500rpm).

few road cams need more than that, because thats there design rpm.

for instance if you want more rpm just use a higher rate spring!

also because the COB system does NOT need really high rate springs, dont waste energy using to much spring!(it can hurt the engine with needless wear).

 

The reason for lightening the new valves is because they are heavier than the ones that came out.

Also the intake valve stem is 0.003" longer than the original valves, so these valves are for a 5.3L engine I found in the ROM that the valves were shortened for 6.0L.

 

.

nice find warrjon, be interesting to know why Ford did that?

 

They did change the tappet (follower), tappet shim , valve collar and the valve . It was reduced weight.

 

What about the springs are they lighter in the 6.0L for lighter valve train?