333 409 heads

[Jim Sullivan]

I have 2 sets of 333 heads. I will be building a 348 down the road. What size valves would be a good choice if I decide to rework the 333 heads? I am only looking for a dependable street engine, with a little more power than stock, for cruise nights.

 

[Don Jacks]

Jim,I think I'd go with 2.06-1.72 valves with a bowl blend to clean up the machining "marks"left from opening up the valves. This should give that engine a nice little shot in the arm ,especially when teamed with a small,modern grind cam,and small tube headers.

 

[1961BelAir427]

I have 2 sets of 333 heads. I will be building a 348 down the road. What size valves would be a good choice if I decide to rework the 333 heads? I am only looking for a dependable street engine, with a little more power than stock, for cruise nights.

Without breaking the bank, I'd look into something like Manley "Race Flo" valves in the stock sizes (2.06" / 1.72" ???? Someone correct me if I'm wrong!) that are made for big block chevys. I think the length is a little longer than the 348/409, but they will fit. That will effect your pushrod length, but you will need to have those measured and order the right length regardless since each build is specific. Also, I think the valves being a touch longer makes spring choice simpler. That line of valves has "necked-down" stem just below the valve face. It is 11/32" diameter in the bowl area VS. the rest of the stem being 3/8". That will give you a mild flow increase along with them being a nice stainless one-piece valve. They are affordable too.

 

[62impala409]

I think my question on valve size will dovetail with Jim's question. Is their a benefit for the bigger 2.19 intake valve in the 817 casting if you are not going to use headers? Just use stock 2 1/2" manifolds. I had my heads rebuilt using the stock size stainless valves and run the full exhaust system with a mild roller cam setup. Leo

 

[Don Jacks]

Ronnie once told me that big block lenth valves in a w engine made getting the valvetrain geommetry a real pain.One can buy w length stainless valves from places like Show Cars for about 160.00 per set of 16.

 

[1961BelAir427]

Ronnie once told me that big block lenth valves in a w engine made getting the valvetrain geommetry a real pain.One can buy w length stainless valves from places like Show Cars for about 160.00 per set of 16.

I'd listen to Ronnie then because he definately knows what he is doing!!! Thanks for the save Don.

 

[Jim Sullivan]

Is it any more difficult to install the 2.19 valves as opposed to the 2.06 valves? It sounds like the 2.06 valves would perform better on a mild build. I have had a set of 2.19 valves sitting on the shelf that I didn't use on my 409. If it takes the same amount of work to install either size the only questions would be if there is enough clearance in the stock 348 bore and would performance be hurt with the larger valve on a mild 348 build?

 

[Don Jacks]

As Ronnie said,I doubt that you'd notice the difference in a street driven engine.No,Idont think it'd be much harder,and it would save you the cost of having to buy new intake valves. As long as you keep the valve lift under about.550 ,and no cam that you'd want to use in the described engine will come close to that,you'll be fine Jim.

 

[Jim Sullivan]

Thanks Don!

 

[Don Jacks]

What are you putting it in,how much compression,basicly what is your build plan,or idea,for the engine Jim?

 

[Ronnie Russell]

The bbc valves are about +.250 to .300 long. I have used them but the geometry sucked. Especially ex. Much easier to get good installed spring height but the geometry always worried me. We went to stud girdles with that set-up and it all stayed together but I would not used bbc valves again.

 

[1961BelAir427]

Thanks for keeping me straight Ronnie!!

 

[CDNpontiac409guy]

I'm going to go measure them right now.
In 333 heads, going to a 2.06" or 2.19" intake size, I like the BBC valve better. When modifying the seat, let the valve seat higher by about .030". Obviously, make sure you have adequate valve pocket in the pistons.
The advantage of this, is you get a very desireable 1.82" to 1.85" spring installed height.

 

[models916]

I think the smaller ports on the 333 work out better on the street with 3:36-4:10 gears than the 690 heads.

 

[61 Bubble]

Nice amount of info coming out here.

 

[Jim Sullivan]

What are you putting it in,how much compression,basicly what is your build plan,or idea,for the engine Jim?

Don, I'll be building the engine for either my '63 Impala or Bel Air. Probably shoot for 9 to 1 compression, cam lift maybe slightly higher than a stock 340 horse 409 if possible and a single 4 barrel cast iron intake. I would like it to look like a stock 340 horse 409 engine. I think the car will be a stock restoration. So I don't want anything too crazy at all.

 

[61 Bubble]

WHY that LOW of compression???

 

[yellow wagon]

PLEASE don't go with only 9:1 compression! At the very least 10:1 if not more. 10:1 will run perfectly fine on pump fuel and give your old gal the good stuff....pump premium, no 87 octane nonsense. You will be rewarded with a snappy, MUCH more fun engine!

 

[CDNpontiac409guy]

Factory 340 horse 409 is 10:1... that' a good place to be. You'll obviously need the correct 340 horse cast iron intake as well.
Cam ?
I understand the desire for a smooth idle. However, the factory 409 cam is pretty lack luster.
A modern short duration, high lift cam will greatly improve torque, and even fuel economy. Keep duration at .050", to no more than maybe 206, and have short seat timing.. no more than 268

 

[Jim Sullivan]

The reason I am using the target of 9 to 1 compression is that I will be using a 348 truck block with two notches in the cylinders. I figured I would not be able to get the compression up very high. If I can get it higher, I will. As far as cam choice, I am still not sure what to use. This build is barley in the planning stages at this time so I really appreciate all of the information every can offer. I look forward to any and all recommendations and advice. This site and all here are the best!!!!!