Timing 438 to 421

[DrHammershaft]

Hi,

I'm just wondering what is involved in timing 438 cams to 421 spec for more power?

Also, is it worthwhile?

Cheers

 

[Kyle 86]

Im going to be doing this also. You will gain a bit more top end yeah

 

[marinemackay2003]

iirc the exhaust cam is retarded by about 5 degrees on the 438's

so you could possibly use the group n timing tools exhaust side as a guide as that is around 4 degrees retarded but 7 degrees advanced on inlet

 

[DrHammershaft]

Cheers for the input! Say it was set to 4 or 6 as opposed to 5, how detrimental would this be?

 

[marinemackay2003]

not to sure on what the detrimental effects would be tbh, but they are rather sensitive to a degree here or a degree there when it comes to engine timing
so get it spot on imo or you could loose a fair chunk of power