changing valve sizes

[74rrduster]

I'm going to change valves in a set of big block heads. Going from 2.08in and 1.74ex to 2.14in and 1.81ex. The stock valves are the tulip type. Would it be better to go back with naihead type valves?

 

[68GTX4SPEED]

Welcome

 

[IQ52]

The flatter valves will work just fine. Do you intend to do some port work also or just install the valves?

 

[74rrduster]

I'm going to do some porting and bowl work

 

[Cranky]

Generally, the tulip valves are a tad lighter but you lose a tad of compression with them. It just depends on deep the tulip is. The valves in my Eddy heads have very little tulip to them....

 

[Meep-Meep]

The only wedge heads I have seen come from the factory with tulip intake valves are the Max Wedge. It has been proven through flow testing (by the DC gang I think) that the nail head valves are better on the wedge motors while the tulips work better on the HEMI. The other thing to consider is going to a larger valve on a stock head might be moot because the cross sectional area of the port around the push rod is still small. Extensive port work will be required to make the 2.14 valves work to their potential.

 

[74rrduster]

Bowl work

I got the porting templates from mopar. I'm using them and going to cut down on the guide bosses. Where else do I need to concentrate on?

 

[Meep-Meep]

Hard to say without a flow bench, but the area around the push rod can probably be widened a bit. Again, you will need a flow bench to make sure you don't kill it.