5 MM Guides vs, Stock Dia.

[madmikeracing]

5 mm (.195) vs stock .216 ? Is there any real performance increase over such a small diameter, I was sourcing some large titaniumn valves and wondering about the 5 mm stems if they help? The DLC coating s I really Like! Mike

[rapidray]

Mike, we played with custom guides in the mid 80s & saw MINIMAL airflow gains. The cost of the custom made guides didn't validate the lack of gain. The gain was REALLY minimal, like only visible on the flow bench & NOTHING on the dyno or track. If you are looking at a cheaper supply of valves, like used from another model, make sure the stem lengths & keeper groove locations are correct. We have tried that too, without success.
Ray.

[madmikeracing]

Thanx Ray I figured that, I even thought of just grinding down the stems where they are i nthe POort area? Anyhow was buying titaniumn valves and was curious if I should even go 5 mm stems? Thanx Mike