Trixie Gets the Anne Boleyn Treatment

Status
Not open for further replies.
Dan1950

Dan1950

1974 MK II Roadster
VIP MEMBER
Joined
Aug 19, 2021
Messages
1,466
Country flag
OFF WITH HER HEAD!

Trixie Gets the Anne Boleyn Treatment



Very fine scratches in the outboard side of the port cylinder but no measurable wear. Bores measure 77mm top to bottom with no ridge at the top.

Scratches can barely be felt with a fingernail.

Trixie Gets the Anne Boleyn Treatment



Exhaust seats and valves need work.

Valve stems look great and no excess guide clearance.

Trixie Gets the Anne Boleyn Treatment


Trixie Gets the Anne Boleyn Treatment
 
Last edited:
Taking the head to Precision Cycle in Ottawa, ON for exhaust tread repair on the starboard side. He does an insert similar to what Jim Comstock does.. Less than 1 week lead time and within driving distance.
 
Dan1950 said:
Taking the head to Precision Cycle in Ottawa, ON for exhaust tread repair on the starboard side. He does an insert similar to what Jim Comstock does.. Less than 1 week lead time and within driving distance.
Click to expand...
And the performance work ?
 
Schwany said:
What, you didn't want to wait 18 months? ;)

Good on ya. :cool:
Click to expand...
Since I have some experience with oversized valves and porting, I'm going to get some seat cutters and do the valve job myself.
 
With 'er 'ead tuckced underneath 'er arm...
I recall my rather singing that.
 
Ordered . 020 over Maney/JS pistons with graphite coated skirts from JS Motorsports. I can work on the heads while I wait on the pistons.
 
Last edited:
Opted for the 10.1:1 pistons. Looking to retard the closing of the intake valve to reduce cylinder pressure at low RPM.
 
Dan1950 said:
Taking the head to Precision Cycle in Ottawa, ON for exhaust tread repair on the starboard side. He does an insert similar to what Jim Comstock does.. Less than 1 week lead time and within driving distance.
Click to expand...
That's my guy in Stittsville Ottawa. My inserts still doing a great job after some 4-5k miles this season.
 
Dan1950 said:
Opted for the 10.1:1 pistons. Looking to retard the closing of the intake valve to reduce cylinder pressure at low RPM.
Click to expand...
How exactly do you plan to retard "only" the intake valve closing time?
 
Schwany said:
How exactly do you plan to retard "only" the intake valve closing time?
Click to expand...
I have an idea with the tappets.

Since the Web 312a can be utilized with either flat or 4" radius tappets perhaps a combination could yield a "dual pattern" duration at the valve.
 
Might be a good time to have a look at the threads for the three studs.. Well known to let go in the head . One less worry down the road .
 
Dan1950 said:
I have an idea with the tappets.

Since the Web 312a can be utilized with either flat or 4" radius tappets perhaps a combination could yield a "dual pattern" duration at the valve.
Click to expand...
Interesting idea. Ask Jim Schmidt what he thinks about that. He has probably tried just about everything imaginable.

I forgot what the reason is for reducing cylinder pressure on the exhaust stroke at low RPM. Don't get too technical, I'll fall asleep. :)

10.1:1 isn't that much compression, and you can knock a little of it off with an .032 or .042 copper head gasket if you are concerned about it. JS Motorsports sells a variety of head gasket thicknesses.

I'm a little surprised nobody else has chimed in. Maybe they ran away when you said you plan to do your own port work. Nothing at all wrong with that, but it's one heck of a tight space to be practicing in. Intimidates me and I have a spare head I could ruin. Seriously I hope it works out. It would be very satisfying to get it right the first time.
 
Schwany said:
Interesting idea. Ask Jim Schmidt what he thinks about that. He has probably tried just about everything imaginable.

I forgot what the reason is for reducing cylinder pressure on the exhaust stroke at low RPM. Don't get too technical, I'll fall asleep. :)

10.1:1 isn't that much compression, and you can knock a little of it off with an .032 or .042 copper head gasket if you are concerned about it. JS Motorsports sells a variety of head gasket thicknesses.

I'm a little surprised nobody else has chimed in. Maybe they ran away when you said you plan to do your own port work. Nothing at all wrong with that, but it's one heck of a tight space to be practicing in. Intimidates me and I have a spare head I could ruin. Seriously I hope it works out. It would be very satisfying to get it right the first time.
Click to expand...
By retarding the closing of the intake valve on the COMPRESSION stroke the "dynamic compression" will be reduced. That will make kick starting somewhat easier. Retarded cam timing also has the effect of raising the RPM of the powerband.

I've done port work on SB Chevy and HD Panhead heads.

My idea is to do the 4" radius on both the leading and trailing edges of the exhaust tappets and only radius the leading edge of the intake tappet. The flat trailing edge of the intake tappet will retard the downhill curve of the intake valve closing. This will delay the closing point a few degrees and perhaps allow more breathing throughout the mid/high RPM range. A bit of torque will be sacrificed at lower RPM but torque should increase in the midrange and higher RPM up to redline. I don't want a flat leading edge on the intake nor on the trailing edge of the exhaust as it might cause valve head tangling.

I have seen similar "dual pattern" duration achieved by utilizing a different rocker arm ratios on the intake/exhaust respectively.
 
Last edited:
Schwany said:
Interesting idea. Ask Jim Schmidt what he thinks about that. He has probably tried just about everything imaginable.
Click to expand...
Jim Schmidt called me today regarding my JE piston order and I ran the hybrid flat/radiused lifter idea by him.

He didn't see any problems with my idea as long as the oversized intake valve didn't tangle with the exhaust valves given the cam grind.
 
Status
Not open for further replies.

Similar threads

Schwany
P11 gets the JSM treatment
3 4 5 6 7 8
Replies
146
Views
18,061
Schwany
Schwany
Hobot
  • Locked
Trixie not the happiest sound yet
Replies
2
Views
691
DogT
DogT
Back
Top