That is exactly what I did with the intake ports, the head I matched to the gasket and the manifold I left slightly smaller.

 

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great, you will find that engine building is just common sense logic,.
for at least the past 100 yrs! like guys our age fall into.

but i think what is reffered to as common sense is going to change in the future , to those born in past 20yrs and onward will have a different common sense!

 

Yes, back before my time when they switch from wood to metal props...
I recommend a wonderful book called "the new science of strong materials"
actually it is quite old now...

 

Started on the exhaust ports. I removed all of the flat, narrowed and profiled the guide boss without going overboard on the bowl size. I deepened the bowl slightly between the guide and port wall.

Heads are off to the shop tomorrow to have the air injection holes TIGed up, then I'll finish up on the bowls and polish the exhaust ports.

 

Wondering how many CC's you had for the heads before and after the work you have done?

 

29cc before measured with a syringe. and about 32cc after measured with a burette, I have not CC'ed the heads yet as they are not perfectly flat and I gat a leakage of the fluid, they are going off today to have the air injection ports TIGed up and I'll have them planed while they are there. Then I can adjust the CC of the chambers.

The interesting thing is - everyone blames the pocketed exhaust valve for the HE's inability to make power, this totally disregards the massive amount of shrouding on the intake valve's very small pocket, which shrouds the intake valve until 1/2 lift.

I'm using stock cams and not really after peak HP, I expect the engine to put out around 450flb of torque and run well to around 5500rpm with a 6000rpm rev limit.

 

If I read that correctly, your goal is to improve low end torque at the expense of high end power? That would make a great road/touring car.

 

Yes kind of.

I am building the engine with torque in mind and will let peak power be what it is. The 6.0L only made 10% more peak power than the 5.3L, but if you look at the power curve, power was up 50% at 2000rpm.

I have been told that 2 of the other 6.7L XJS's that were built twisted 1/2 shafts on the dyno.

If the engine runs out of puff before 5500rpm then I will look at at adjusting cams and intakes.

 

Ah, yes, port and polish and port matching. Dates, way back. On flat head Ford V8's, an additional process was involved, known as "relieving". Removing metal to enlarge the path from the valves to the cylinder. A shroud in effect. Of course, that increased combustion chamber volumn and decreased compression. Made up for by milling down iron heads, or better yet, better alloy heads. Properly done, They would "rip".


Concept: An IC engine is but an air pump. Enhance the ability to pump air and add fuel and power goes up.


Looking forward to the report on fire up.


Carl

 

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CARL, i remember those days , back when i didnt know sh$T, a had the 1934 Heads milled/planed to much,valves hit the head, so took out the camshaft, and with a bench grinder just ground some off the nose of lobes, put it back together and off we went driving!

sold the car and never heard of again!

aint life wonderful.

 

Ha!!!


1. Your cam regrind lessened valve lift, but possibly increased duration!!!


2. Circa 1947, we drove my "hot" T to a friendly machine shop. The Prop not only thought we were nuts, but knew we were. We pulled the head and figured out how much to chop and rely on the gasket for valve clearance. Although fussing like crazy, he cut it down. A couple of trial fits and we decreed it "right". Put it together, it ran.
Took a goodly amount more pull to crank it up. Wowee, it is great. Oh, oh, connecting rod adjustment became frequent!!! Just file the caps a bit til almost snug. Mike, plastiguage? Unheard of then.


Carl

 

warron; have you had the heads resurfaced yet?

something to think about, is the head really warped or not flat?

if it is not flat, then the cam shaft bearing bores are not in alignment also.

if you surface head flat ,when tightened down the cam bores will be out of straightness.

it is common on inline 6 heads(not much problem with 3/4 cyl. heads. big problem if its an OHC straight 8 head, like a 19 30s USA Duesenberg,ASK me how i know?

a quick check is bolt the head down(with old gasket) before it is assembled, put the cam in without any thing on it, and see if it will rotate BY HAND , if not it could be a prob. if run that way the cam will be constanly bent in possibly crack/break!

if you can spin it by hand ,good to go!

talk to your machinist, and ask some of these questions?

i did many cylinder head rebuilds, and i used an electric oven to heat and straighten the head ,BEFORE the resurfaceing , also ask if he uses a stone or carbide cutter type machine?

 

just comes to mind, how many here have ever rebuilt a Duesenberg engine, or ever seen one in real.

also got a pic someplace of a Lamborgine V12 engine i am doing a mainbearing line bore work on it , along with both V12 LAMBO 4 cam,4 valve head rebuilds!

on the DUESY, after i had it finished , the owner said thank you , nobody local Daytona area would touch it, for fear of LIABILITY reasons, bunch of ******.

then he tells me ,if the block was damaged beyond repair, a used replacement block was $150,000. usd, and only one was available in the world that he knew of!! oh sh$t.

more useless crap that come along in life!! LOL

 

No the head has not been surfaced yet. I do not think it's warped the issue is corrosion and a buildup of old head gasket crud on the head surface prevents the perspex from sealing properly, so get leakage of the ccing fluid.

The head will be checked for flatness before it's finished, with the Jag V12 I can re-surface both sides to ensure the cam carrier is true. I have bolted down the cams and I can turn them by hand with the head on the bench.

 

The guy could not get the TIG torch in the port, so I decided to machine these inserts, they are 0.002" interference fit, to get them in I put them in the freezer then tap in with a punch and hammer.

They are aluminium so will expand and contract same as the head so will not fall out.

.

 

What are they Warren, valve guides?
Greg

 

Pretty work! Only problem I have with your heads is when complete they need to be framed and mounted. You can't just hide all that beauty in an engine!

 

I'd say plugs for the air pump pipes in the exhaust valve port...

 

https://youtu.be/Bu2bq9ad0e0

Is it really works? If yes. Where to buy?

My inlets has not holes. Your alum bullets is good.

 

I turned them up on the lathe. I wanted to plug the air injection hole to reduce turbulence in the exhaust port.