Performance Camshafts Update 2021

[Swift]

question 1) Can this be compensated by milling passenger side bank x amount you think?

2) Do you know by how much you were able to compensate? And that was just on the passenger side cam...or was that on both cams on the exhaust side?

I know of Andrews, probably pointed you in the direction. Since these are new cam cores, they could grind based on your info to get at least close, I could degree them in a block and let them know by how much to address. This could all be done in a cnc program nowadays i think.

[buzzard]

You cannot compensate. It IS four different lobe designs. You need to get the paper,do the measurements and have Andrews design the lobes. Anything else is fantasy.

[buzzard]

And I wouldn't go chasing too much power. At 780hp @ 14.5 PSI boost I can't keep the heads clamped on. Head gasket failure at 63 miles distance in competition use. The main caps are chafing on the block with total run distance from new of 90 miles combined testing and competition.

[buzzard]

As the cam base circle gets smaller it changes the angle of the rocker. You must maintain the specified/Honda oem base circle diameter. There are no shortcuts here.

I suggest you talk to Andrews, weld up two lobes on each cam and start from there. That way if there are problems you can weld again to maintain the design base circle. Did I mention there are no shortcuts here?.

[Swift]

My confusion lies in the fact you have always said it was due to timing...because of the belt and decking the heads makes it worse. Since these will be NEW camshafts I would of course have him maintain the oem base circle since that is kinda the whole point. Others can get drastic grinds, i am just doing a performance cam for the C35 and then a slightly better camshaft just about a type 2 for the C32.

[GreekPower]

Originally Posted by buzzard

And I wouldn't go chasing too much power. At 780hp @ 14.5 PSI boost I can't keep the heads clamped on. Head gasket failure at 63 miles distance in competition use. The main caps are chafing on the block with total run distance from new of 90 miles combined testing and competition.

I’m curious what motor specs and parts your building in your motors?! I have forged pistons (9:1 compression), I beam rods (rated for 1200hp), ARP hardware and headstuds. OEM type 2 heads with some port work, Type 2 cams, on a 3.5 block with custom intake manifold. It makes around 640whp (which would be over 780hp at the flywheel). So I’m curious what specs you have? Also what transmission and clutch your using in the buggies

[buzzard]

Originally Posted by Swift

My confusion lies in the fact you have always said it was due to timing...because of the belt and decking the heads makes it worse. Since these will be NEW camshafts I would of course have him maintain the oem base circle since that is kinda the whole point. Others can get drastic grinds, i am just doing a performance cam for the C35 and then a slightly better camshaft just about a type 2 for the C32.

You are confused. Yes, milling the heads will alter the cam timing. It will retard the cams. As the timing belt crosses the head/block join 3 times(4 times actually but its only the driven side that is a problem) the drivers side bank (US) is retarded and the passenger side bank cops it three times as the belt is effectively longer than it needs to be.

However, due to the contact point between the rocker "shoe" that slides on the cam being different from one bank to the other, you need to design the lobe to suit the rockers. Please have a look at the contact point between the rocker "shoe" on one bank and the other at the start of the intake lift. Completely different, and thus effectively a different ratio rocker.The lobe is designed so as to give equal lift and timing on both banks.


If you do not accept what I say (and I have no problems with that), have a set of cams reground with identical lobes for both banks, fit to the engine and measure.

You can test this very easily without a degree wheel.

On one cam pulley make a mark exactly 180 degrees from the factory timing mark (count the teeth).

Put the engine on TDC.

Remove timing belt.

Rotate crank about 60 degrees (this will move the piston away from the valves)

Rotate cam 180 degrees, align new mark

Rotate crank back to TDC and refit belt.

You will now notice that intake valves on CYL 1 and 5 open together.

Fit dial indicators on cyl's 1 and 5 to measure valve lift.

Rotate engine and observe how closely the dial indicators track each other. In my experience the indicators will track within 0.002" of an inch of each other with standard Honda cams fitted and all parts in good condition.

I have reground cams here where the error exceeds 0.100" lift bank to bank.

You will either need solid lifters or welded hydraulics to stop the stock lifters collapsing under the valve spring load.


Below is the email I received from John Andrews in 2007

Hello Chris:

I am attaching two PDF documents to this email. They both have basically the same information.

Our experience with OHC oscillating follower type cam systems is that:

1. They are very difficult and confusing to everyone who works with them.

2. Without an engine setup and degree wheel placed next to a cam grinding machine, getting the desired final cam design and timing output will be very time consuming and expensive.

Let us know after you have reviewed the attachments.


John

Andrews Products

The reason for this is not only do you have to design the lobes correctly to suit the rockers, you also have to get the lobe centers correct. This is a complex system and there are no shortcuts.

The cam timing can be measured very easily once you are setup to do it. I have an engine setup in the corner of the engine room specifically for measuring cams.

[buzzard]

Originally Posted by GreekPower

I’m curious what motor specs and parts your building in your motors?! I have forged pistons (9:1 compression), I beam rods (rated for 1200hp), ARP hardware and headstuds. OEM type 2 heads with some port work, Type 2 cams, on a 3.5 block with custom intake manifold. It makes around 640whp (which would be over 780hp at the flywheel). So I’m curious what specs you have? Also what transmission and clutch your using in the buggies

Our spec is similar except I am at 9.75:1 comp on E85. Please remember this is a competition engine that sees a lot of full throttle.

Car is fitted with an Albins AGB gearbox with torque converter.

[buzzard]

https://www.youtube.com/watch?v=-nyHBick22U

3:30 you will hear the Honda doing it easy. Shame about the music

[buzzard]

https://www.youtube.com/watch?v=7do00MdY9gg

From 0:51, Yokohama sponsored.