camzaro28

I dropped my heads off at a local shop, very reputable in the area. Anyway going through everything with him and telling him my overall goals, whats done to the car, etc. He recommended I get a bigger valves, so I agreed.
Anyway I went back to a couple of my buddies, and they said to stick with the stock vlaves with a 3 angle valve job, that way I wont have to spin it to the moon to get good results.
So at the moment I am torn on what to do, and would like some more input. Here is the basic rundown of what I am shooting for.

I have full bolt ons, minus 58TB ( soon to come ), 3.23 gears ( hoping to stay with them ), 3200 2.0 stall. I am sticking with the stock bottem end for the time being and only want to spin it 6200 MAX, and would like to only go to 6k RPM if it was my choice.
I would like it to pull hard through the entire rpm range, not just peak real high. So staying under 6k RPM, what are my best bets?

BUBBA

To begin with: Know your shop. I.e, just don't accept that it is reputable in the area. Check it out. And then, and only then can you put any stake in what they recommend. Having said that, you don't absolutley need larger valves and the most important part of the heads is deep pocket work, unshouding of valves, 3-angle job-----and with out going with RRs and a cam to match the heads, you are restricting your performance.

The cam will determine your RPMs and curve of power.

Again, you better be sure about the headshop. Think about it---if they recommend larger valves (and they are really reputable) why wouldn't you rely on their judgment over your buddies?

One thing that is an absolute must when it comes to working on these engines is knowing the reputation of the mechanics and shop in general. Without that you are pi$$ing up a rope. JMHO

BUBBA

BTW, with an A-4 and the desire to keep your torqiness, I'd opt for a 227 cam and 3.73 gears. The 227 is a 6 grand cam and with your convertor and some lower gears you can hire out as a tow truck.

camzaro28

[QUOTE=BUBBA;4431613]

Again, you better be sure about the headshop. Think about it---if they recommend larger valves (and they are really reputable) why wouldn't you rely on their judgment over your buddies?

QUOTE]

Well, I agree with both of them, that is why I am torn on my decision. Yes the valves will give me more power, but if what my friends are telling me is true, is that it is going to move my RPM peak quite a bit higher, so not do it.
Basically, is it worth the xtra 250 for bigger valves? And then, will it move my powerband up higher? If so, how much?

Haha, thanks Bubba. Well I guess I should say that they are well known throughout the buick grand national group. They do alot of race motors, so I think that is why he is recommending me to go full bore with the heads.
I am going to put a cam in ( was going to get the flow numbers then give them to cam company and go with there suggestion ) and already bought the crane 1.6 SA rockers.

Buttercup

Moving to larger valves can hurt flow if the porter doesn't know how to properly unshroud them. If the porter recommends larger valves you can only assume he knows how to work the seats, bowls, and chambers to accommodate them. If he doesn't, he shouldn't be porting your heads anyway.

Don't listen to your buddies if their reasoning for avoiding the larger valves is "have to spin it to the moon to get good results".

camzaro28

Buttercup, them werent his exact words. I just said that to emphasize what he was saying.

Well here is something else I put into consideration that I didnt say earlier. I dont want a huge cam, trying to streetable, but achieve some good results. Does that have anything to do with the what I do to the heads, or with what cam I choose?
And here is the shop I am having the work done at http://www.championracingheads.com/

Buttercup

I don't know how reputable that shop is but I'm assuming you've done your homework.

That said, get the heads ported and flowed. Once you know the flow data from the heads you can choose the appropriate cam.

There's a lot more to head porting than just valve sizes. Valve size doesn't dictate all THAT much. You can only go so much bigger before the cylinder bores start shrouding them excessively. There is something to be gained with larger valves if done appropriately but it's not a prime focus IMO.

If the porter knows your intentions, displacement, etc. he will attain the appropriate flow rate and flow velocity while hopefully keep the flow path efficient and do all of this throughout the lift range.

The magic is in the heads and you usually get what you pay for. If the heads are done right you can make more power and be more streetable, all with "less cam".

Unless your buddies know a lot about cylinder head flow dynamics I wouldn't listen to them over your porter.... they would be your porter if that was the case

camzaro28

Hey thanks alot Buttercup, I will take all that into consideration.

The magic is in the heads and you usually get what you pay for. If the heads are done right you can make more power and be more streetable, all with "less cam".
Well I think we are on the same page.

I just dont want heads that flow real good up top, and have to throw a mid 230 cam in there to get good results.
I am wanting to stay in the 220 range ( so the 227 cam Bubba brought up earlier, is sounding good )

speed_demon24

The 227 is a crane cam, its a 210/224. And I would shop around for head places and find a shop that can match a head/cam package for you. I sent my heads to Lloyd Elliot and couldn't be happier with the customer service. He sells heads/cam packages and I'm sure he can set you up with a cam that works in the stock rpm range. There's a reason why 9/10 people online send their heads out to a reputable place to get ported over some local place.

camzaro28

There isnt much difference in this place and LE if you ask me.
Put this into perspective. 9 out of 10 guys on this forum send them to LE, well 9/10 guys from GN forums send them to this place. I am just lucky enough to have them within 2 miles of my house. Well, I guess the truth will be told ( good or bad ) once I have all the bugs sorted out.

mdacton

IMO there is no need for a bigger valve esp, on a stock bottom end....there is more you can do to the vales or get better ones that flow beeter, undercutn polished etc....the bigger valves can hurt you

camzaro28

This is pretty much what my friend was telling me. Not worth the xtra $250.
Thanks Mdacton Been reading some of your replies as of late, and you seem to know your stuff!

mdacton

acctually I don't.....I just read alot of stuff on here
not as smart as I my seem over the net. I will be the first to addmit that

the way I see it, the stock valve in stock form will only hurt flow but so much....using that bigger valve you have to consider most of that air has to travel around that valve at the lower lifts witch it is at for a longer duration of time....so in a mild app a big valve would hurt. And also the bore of the cyl. plays a part....a stock cyl. 4.00 plus the bigger valve will hurt you.

Spend that $250 on the best valve train parts, this is where I have made my mistakes...going with cheap..junk

Buttercup

It's always a trade-off. The larger valves provide for a larger curtain area and that provides higher flow at those important lower lifts. If you go too large than the valve may not be as much obstruction but the surrounding material may be. You can't take the simple view of just the valve, or just the seat, or just the CC, it all works together. Even with a stock 4" bore you should be able to gain a few percent more flow with larger valves IF the CC, seats, and throat are optimized for it. The valve seat geometry, valve seat height (including differences between intake and exhaust), and so on have a large impact.

At higher lift the flow characteristics are completely different than at low lift. The major port and throat contours start becoming a more significant contributor and flow starts to bias across the valve.

It's all about compromises and everything working together in harmony. A good porter knows what works best with his ports.

Keep in mind that there is a big difference between a Buick 3.8 head and an LT1 head. A pro 3.8 porter does not necessarily make a pro LT1 porter.

I'm no professional either and I doubt I even sound smart on the 'net but these are my thoughts.

mdacton

Buttercup.....he just wants to know if he puts bigger vales in will the power gain be worth $250....simple IMO, no

yeah you could get a gain if you were going to do all the stuff you did and work the head a little more, but on a stock or close to slock bottom.....what are we talking...less than what 5 h.p.? money would better be spent elsewhere, again this is just an opinion and I am no expert on this whatsoever