Are 2.05's for highly modded motors?

[TYTILIDIE]

Just curious. I am about to pick me up a set of VORTEC heads soon here and am seeeing around that everyone likes the 2.05's. I thought these seemed a bit on the large side. Im putting them on a stock motor but will eventually go with a stout bottom end and bigger turbo, probably next year. Would it be dumb to do this right now?

 

[Six-is-Enough]

Re: Are 2.05's for highly modded motors?

You get into valve shrouding if the combustion chamber is not ported with that size valve. Also I think a 2.02 valve is the largest you can use with the stock valve seats. Any larger and they have to be cut out and replaced, which equal $$$$$.

Most people just go 2.02 on the intake because they are upgrading the valves anyway. Not any more cost to go to a 2.02 over the stock size. But to get the full benefit you would need to massage the combustion camber to unshroud the valve.

 

[UR50SLO]

Re: Are 2.05's for highly modded motors?

I'd agree with Jeremy....

I just put my wife's engine together with 2.02'/1.6s and I did ALOT of work in the comustion chamber to allow it to get into the bore. You'd need a larger bore to run the 2.05's. If you don't relieve the chamber with 2.02's you'd hurt the flow over using a smaller valve.
That's just my experience.
~Scott

 

[TYTILIDIE]

Re: Are 2.05's for highly modded motors?

Cool Ill keep this in mind.

 

[Windedv6]

Re: Are 2.05's for highly modded motors?

I had my heads done by Flow Tech, a very reputable company for highend heads and they recommended staying with 2.00 valves. It must be ok as I am pushing a lot through them and they seem to work fine. They also had me stay with 1.5 rockers. I run 10s in a 4,000 lb Typhoon with 72GTQ turbo.

John

 

[critical]

Re: Are 2.05's for highly modded motors?

You might try 1.6:1 rockers on the exhaust side for your stock engine.
I dont know how much itll change the volumetric efficiency, if any, but will def reduce exhaust back pressure.
I may do this w/a set of 7113 vortecs ive got, since the chip is stock anyhow.

 

[It's just a six]

Re: Are 2.05's for highly modded motors?

Also, a little more to add, if you do put in 205's in & do not open up below the valve seat /bowl area, there will be no advantage in doing this, you would need to port/open things up more to get it to flow better.

If the chamber walls are too close to the valves you will actually hurt airflow.(You'd be better of w/stock valves if they are shrouded too much w/the 205's)
If you need more advice contact Dave @ West Coast cylinder heads,James Thomas has his heads there.You can send your heads there also if you'd like.
818 705-5454