Forum » General Engine Building Discussion » B18c Skunk2 pro 2 camshaft

B18c Skunk2 pro 2 camshaft

General Engine Building Discussion

Talk about engine building here. New products, tricky questions or showcase your work - If it's engine building related it's welcome here.


Page 1
Author
65 Views

how do I read this cam card

CAM SPECS:Intake Duration / Lift: 200° / 12.801mmExhaust Duration / Lift: 276° / 11.988mmIntake Centerline: 98°Exhaust Centerline: 106°Valve Clearance (Intake / Exhaust): .007” / .008”RPM Range: 1,500 - 9,400 rpmHP Gains: 20 - 25 hpTorque Gains: 18 - 22 lb-ft

im trying to degree the cams

trying to measure intake and exhaust cam timing

This should show you what you gotta do.

http://www.superstreetonline.com/how-to/engine/0704-ht-how-to-degree-camshafts/

No offense intended*, but that is a lot of cam' - do you have the rest of the parts needed to support it?

On that, DO NOT forget to check valve to piston clearance as, even when they are 'supposed' to fit, there can be issues with some engines and combinations.

*just that cam' timing is a fairly early, basic skill to pick up and a bit concerned you may be getting in a bit deep on the build for a beginner.

great info thank you ADAMC

Hi,

Webcams has the best easy way to degree your cams that I have come acrss

http://www.webcamshafts.com/pages_misc/degreeing.html

have a read, they even have a calculator for your centerlines,

Hope that helps

Hey guys, that information on the two links posted above is a little concerning and certainly won't get you accurate results.

First let's deal with Superstreet's method - You can't accurately dial in a cam based on finding the point of peak lift. There's significant dwell around peak lift that makes it impossible to be even close to accurate with your cam timing. This is the same reason why we can't accurately find true TDC by just measuring the point where the piston reaches the top of the bore. Next up we have the Web Camshaft website which again is NOT the recommended way to degree cams. The majority of cam profiles have some degree of asymmetry in the grind and using Web's technique will guarantee that the cam timing is slightly out in this instance. To make matters worse Web are suggesting that you do this as the valve first opens off the seat which is going to give you the most amount of error with an asymmetric grind.

The preferred approach is to use the opening and closing points from the cam card to degree the cam. This allows the timing to be dialled in accurately and also allows a sanity check as you can confirm the duration matches what the cam card quotes. Without trying to promote our own course, I'd strongly suggest you take a look at it. We cover the various ways of degreeing a cam and talk about the pros and cons of each method. Finally there's a six step process and a worked example specifically on a Honda B18C.

Now with all that being said, the information you have on the cam card isn't sufficient to do a proper job of degreeing that particular cam so I'd be asking for the opening and closing data from the cam supplier. Failing this you will have no option but to use the centreline method. Instead of looking at the valve opening and closing points though, I'd recommend looking at points 0.050" down from peak lift. This will have you bracketing the centreline much more accurately than using the opening and closing lift Web have recommended.