Oversized valves

[pitaSHO]

Are they worth it? I did some poking around on RCM and noticed that the oversized valves are only one mm larger than that stock size. Are they worth it? The motor will eventually get boost, but that's a ways away. My long range plans for the motor would include:

Low comp pistons
pnp heads
Over sized valves and brass valve guids (maybe)
Tri-flow cams (interference motor?)
Turbo (eventually)

I know I could just boost a stock motor, but I just have the bug to build one. I'm in no hurry and will only do what I can afford, so it could take a while. Any feedback would be appreciated.

Thanks.

Chris K.

 

[Phoenix]

I would like to know as well , but I believe it must be very minimal.

 

[firebat45]

I'd like to see some dyno numbers, larger valves can actually hurt performance if they're to the point of blocking airflow on the cylinder wall side of the opening.

As an aside, if you get low comp pistons, Tri-flows(or +40) will not make the motor an interference motor.

 

[pitaSHO]

I'd like to see some dyno numbers, larger valves can actually hurt performance if they're to the point of blocking airflow on the cylinder wall side of the opening.

As an aside, if you get low comp pistons, Tri-flows(or +40) will not make the motor an interference motor.

As far as dyno numbers, I doubt they would be worth it. More power can be had through just boost. I guess I just want to build a motor that has everything, paint it, make it look new, just for the heck of it.

Low comp pistons + tri-flow cams = non-interference motor FTW!!!! Thanks, firebat 45. I forgot about that.

Chris K.

 

[texantony]

I have them installed on my sho and I did notice a big difference.
of course, I did up the boost a bit and ported the heads but the engine seems to flow and respond alot better. Definitly has more torque up top. No dyno #s yet so this is a purely butt dyno.

 

[NovaSS]

I would only use them on a 3.2 larger bore so they dont get shrouded by the cylibder wall.
As for total number I would bet is was more on who did the install ( valve grind angles ) then the valves them selfs.

 

[pitaSHO]

I have the block stripped all the way down to nothing, ready for the engine guy. I'm getting it cleaned, honed, and painted. And, yes, it's a 3.2. I was planning on using the 3.0 heads, tho.

Thanks for the feedback.

Chris K.

 

[Sho Amo]

i wish there were some dyno numbers for this. its a no brainer askin if it increases power but wether its worth it is based upon opinion.

 

[AREA 91]

257 wheel horse power here on stock valves and springs. Unless you have a big wallet, or going for all out power, I would spend the money elsewhere.