CRX cam timing again.....

[pshipp]

Need some help from the Honda engine gurus... have an ITA based engine in my F prod car and am trying to figure out if the cam timing is set correctrly or not (by the previous owener and engine builder).

After setting the engien to TDC, measured via DTI on piston crown (no timing belt cover...so no alignment marks for front pulley) the alignment marks on the camshaft pulley are not in line with the head top face, more like 8:00 to 2:00 posiiton. I measured the angle of max lift on number 1 inlets and it came up as 112 degrees ATDC, anyone know what it should be for a stcok cam? I have an adjustable pulley so can play around with the timing to get it back in line.

I know the head has been skimmed but would expect to see the camshaft then retarded not advanced as it appears from the alignemnt marks. The pulleys on the car and in the spares box is the stamped steel type with built in key and both look the same.

Any help appreciated.

thanks

 

[bill f]

I just realized that no one has responded to your question. I may offer a tip or two that I use for EVERY engine I build regardless of class or rules.

I'm not a Honda engine guy, but may have access to a certified Honda mechanic. Here are a few thoughts: Begin by establishing a baseline of settings for the engine...

Start simple (KISS) and return the stock sprockets to the cams. Set TDC at the crank (assuming that you have determined the "actual" TDC by the piston-stop method...something redone after each engine rebuild) and position the cams at the proper location (per shop manual) using the cam covers' locater marks. Find a way to mark the cam/head position for future reference (it now is the "zero" mark for each cam, and the cams can be returned to this position ANY TIME the components are disturbed).

Remove the covers, and return the adjustable sprockets to the cams, each set at "zero" on the vernier. Now return the cam belt to the equation, tension set properly.

You now have established the zero point of the cams, with their relationship to TDC of the crank, and you now can move anything with the vernier of the sprockets and KNOW WHERE YOU ARE relative to the crank...and be able to return there anytime.

After using this method, you will be able to test at the track, or on the dyno to find the "sweet" spot of the timing events, cam and ignition. If a head or belt needs to be removed you have the marks established that will allow you to re-set the settings you left.

Methodology remains the same for any engine, not especially the Honda engines.

I hope this helps. It does not give you the greatest performance settings for any particular engine, but will give you a baseline to use for any engine.

If you need any more clarification, write me at:

[email protected]

Good racing.

Bill

[This message has been edited by bill f (edited June 14, 2005).]