cut the stock exhaust valve guides flush

[Aaron91RS]

When people port the exhaust sides of 1g heads do they ever grind the stock valve guides down flush or does it mess things up?

I can't find anywhere were someone did on a DSM, but the ls1 guys have been known to do so, so I wanted to ask if it works for a DSM.

 

[Sharadon]

I can't say that I've looked at the guide on one of these heads yet. But I will say, I've ported many cylinder heads. Port design will determine if it's OK or not. Removing valve guide un neccesarly will lead to faster guide ware and valve seat ware.

Not sure if this helps or not. I need to take a look inside.

 

[Aaron91RS]

I saw this pic but it uses shorter guides not cut ones.
But that is a beautiful thing.

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[jrpmp69]

I was going to have it done on my 1g head but the owner of the machine shop suggested to leave them as they are unless you plan on taking the head apart often like they do on track cars due to the guides wearing out faster and there will also be less support on the valve.

 

[Defiant]

Kind of pointless on a forced-induction car. What difference it might make you'd never be able to measure. I'd rather have the increased valve support and cooling path.

 

[Aaron91RS]

you've got to be kidding.
With that logic you shouldn't get a bigger header a bigger exhaust or a bigger intake, cause you'd never feel the difference.

Power is made in the head.
A head that flows 245cfm is good, one that flows 275cfm is excellent.
why do you think they stick 4 valves in our heads and not two? Airflow!

 

[PieEyedPiper]

you've got to be kidding.
With that logic you shouldn't get a bigger header a bigger exhaust or a bigger intake, cause you'd never feel the difference.

Power is made in the head.
A head that flows 245cfm is good, one that flows 275cfm is excellent.
why do you think they stick 4 valves in our heads and not two? Airflow!

I see your point, but when was the last time an upgraded intake or exhaust made you have to rebuild the head?

For the best performance, sure do it. But for us more practical folks, we prefer reliability over the miniscule gain this modification would give you. It's possible that 1lbs of boost > than this mod.

 

[Defiant]

I can't find anywhere were someone did on a DSM,

There just might be a reason for that.

but the ls1 guys have been known to do so, so I wanted to ask if it works for a DSM.

Are they forced induction?

 

[nitrouskris]

do not do it. i have had a head done and flowed,both ways and there was only about a 5 cfm diff. the e.t was the same