[Richkidd87]

Why is it bad to put new aftermarket heads on your car right out the box?

[USAFS197]

It's likely because there's always some room for improvement if you clean the heads up. Think of them as a canvas instead of just slapping them on, as cast. Unless if it's a completely aftermarket head that was created out of a single piece that was CNC into the head.

[Blk16SS]

Originally Posted by Richkidd87

Why is it bad to put new aftermarket heads on your car right out the box?

Who said it was bad? That's false info..

[oldman]

http://www.onallcylinders.com/2016/11/02/edelbrockThe stock unported heads have yielded some great results here:
http://www.superchevy.com/how-to/eng...-gen-6-camaro/

That is a 140 WHP gain with: stroker, cam, MSD and 103 TB.


-unveils-first-set-chevy-gen-v-lt-cylinder-heads/

I have not seen if they are released, clearly the Victor is a clean slate design.

[PRAY]

I think he may have meant actually taking them straight from the shipping box and dropping them on the car. You should at least blow them out with air and inspect them closely for any left over metal chips and what not.

[Richkidd87]

Originally Posted by PRAY

I think he may have meant actually taking them straight from the shipping box and dropping them on the car. You should at least blow them out with air and inspect them closely for any left over metal chips and what not.

Thank you my friend

[Richkidd87]

Originally Posted by Blk16SS

Who said it was bad? That's false info..

Saw a few YouTube videos

[USAFS197]

That article was confusing about the stroker. First they're talking about a 427, and then suddenly it switches to a 416. If they managed that much power out of a 416, then that's awesome. Also, I don't think they mentioned what kind of fuel they used. Either that or I completely missed it.

[Blk16SS]

You have to take into consideration the stock head is what I would refer too as "big & lazy". The intake runners are ( old man and pray can correct me) somewhere around 298cc's. Yet it flows just a few over 300 c.f. stock. They make power stock but that's not a good coefficient. Power for the most part comes from air speed (velocity). So the most air flowing through the smallest hole typically makes more HP and wins races. An example would be a TFS 235. This particular head flows close to 350 cfm, has a 2.08" intake valve, yet does it with a 235cc port. A better coefficient and more condusive to making power. So my theory on these heads are you're better off with a race valve job as opposed to having them hogged all out, killing your low end power. That's why I can understand they're showing to make excellent power with strokers. Our stock 6.2L are not taxing these heads at all. Its a great head. Just lazy. That's why I strongly believe the new Victor Jr's will be a game changer. In thinking around 360 cfm from a 285cc port..

[oldman]

love the new victor, but if I were to run it, id have to change headers...
412 CID with just a multi angle on the head. Stoker prices are reasonable and with the better rods and lighter piston (assumed) I would feel better pushing this up and over 6900 RPM.



http://www.superchevy.com/how-to/eng...ne-warp-speed/

This keeps me up at night... when you are old:
https://weaponx-c7.myshopify.com/pro...eads-stage-1-3




[

[PRAY]

Originally Posted by oldman

love the new victor, but if I were to run it, id have to change headers...
412 CID with just a multi angle on the head. Stoker prices are reasonable and with the better rods and lighter piston (assumed) I would feel better pushing this up and over 6900 RPM.



http://www.superchevy.com/how-to/eng...ne-warp-speed/

This keeps me up at night... when you are old:
https://weaponx-c7.myshopify.com/pro...eads-stage-1-3




[

That picture is their LS3 port brother. Not taking anything away from Weapon X. I like Ben alot and they do great work. But, my heads are already flowing better than that on my little bench with a 4" bore. I tried to get to the 28" bench with a 4.070" bore on Friday but my guys was gone. Hope to do it this week. I usually see at least a 20cfm gain at 28" on my heads over my bench.

The stock runner measured right at 300cc, my ported runner is 313cc but the velocity is way up. I didn't add any cross section. Just some taper by the IM opening. All the material was removed from the short turn and internal obstructions. I am shooting for a straight bolt on that is worth 20rw. If I get that I will market them. If not then they will be a one off for my car. They will be priced better than headers or a MSD.

[PRAY]

Originally Posted by Blk16SS

You have to take into consideration the stock head is what I would refer too as "big & lazy". The intake runners are ( old man and pray can correct me) somewhere around 298cc's. Yet it flows just a few over 300 c.f. stock. They make power stock but that's not a good coefficient. Power for the most part comes from air speed (velocity). So the most air flowing through the smallest hole typically makes more HP and wins races. An example would be a TFS 235. This particular head flows close to 350 cfm, has a 2.08" intake valve, yet does it with a 235cc port. A better coefficient and more condusive to making power. So my theory on these heads are you're better off with a race valve job as opposed to having them hogged all out, killing your low end power. That's why I can understand they're showing to make excellent power with strokers. Our stock 6.2L are not taxing these heads at all. Its a great head. Just lazy. That's why I strongly believe the new Victor Jr's will be a game changer. In thinking around 360 cfm from a 285cc port..

You made a good point about C/D or coefficient of discharge. Using the heads you described above. Brian Tooley did a good write up about this. I ran the TFS 235 heads on my 02 Z06. 416 with a 247/254 112+2 cam and a FAST 92. The car made 573/530rw. It ran 10.20@136 wiht a best mph of 138. I took Brians advice and designed my own stock 243 runner with 2.04" valves. I got them to flow 240cfm at 235ish cc's. In my Gen 1 CTS-V with a LS3 427, stroke not bore, 243/251 113+4 cam and a FAST 102 I made 570/525rw. So a much heavier drive train with a smaller cam made the same power with 10cfm less flow. It did have 10 cubes but a better C/D. Now I have that same cam in another C5 with my LS3 top end that flows 380@.700 and it makes the same power. So all that extra flow and a much better flowing IM didn't make a difference in power. I think those heads flow 330cfm with the ported LS3 IM attachedon my bench. Head alone on my bench goes 253cfm at .700. I am pretty sure my ported Fast hit just over 290cfm on the LS2 heads. I have perfected my LS2 intake and exhaust ports since those heads. They flow much better down low now and the exhaust is leaps and bounds ahead. I have two motors coming out soon. A 429 in a truck and a stock block A4 LS2 GTO with my ported LS2 heads. We are trying to break 500rw on the stock short in the GTO. The heads I just finished up for that build flowed 300cfm through the ported fast on my bench. My bench is down 30cfm to the 28" bench on my LS2 stuff. So velocity and C/D are very important to over all power.

I will admit that I am crazy temped to throw a LS3 valve into these LT1 heads and see what happens. They are 10g lighter and would provide probably another 10-15cfm down low. They fit on the stock seats as well. Would be a curious test to see what they would do.

The point is to keep the port as small as possible cross section wise with the correct taper and a bunch of velocity, tumble and swirl.

[Richkidd87]

Originally Posted by PRAY

You made a good point about C/D or coefficient of discharge. Using the heads you described above. Brian Tooley did a good write up about this. I ran the TFS 235 heads on my 02 Z06. 416 with a 247/254 112+2 cam and a FAST 92. The car made 573/530rw. It ran 10.20@136 wiht a best mph of 138. I took Brians advice and designed my own stock 243 runner with 2.04" valves. I got them to flow 240cfm at 235ish cc's. In my Gen 1 CTS-V with a LS3 427, stroke not bore, 243/251 113+4 cam and a FAST 102 I made 570/525rw. So a much heavier drive train with a smaller cam made the same power with 10cfm less flow. It did have 10 cubes but a better C/D. Now I have that same cam in another C5 with my LS3 top end that flows 380@.700 and it makes the same power. So all that extra flow and a much better flowing IM didn't make a difference in power. I think those heads flow 330cfm with the ported LS3 IM attachedon my bench. Head alone on my bench goes 253cfm at .700. I am pretty sure my ported Fast hit just over 290cfm on the LS2 heads. I have perfected my LS2 intake and exhaust ports since those heads. They flow much better down low now and the exhaust is leaps and bounds ahead. I have two motors coming out soon. A 429 in a truck and a stock block A4 LS2 GTO with my ported LS2 heads. We are trying to break 500rw on the stock short in the GTO. The heads I just finished up for that build flowed 300cfm through the ported fast on my bench. My bench is down 30cfm to the 28" bench on my LS2 stuff. So velocity and C/D are very important to over all power.

I will admit that I am crazy temped to throw a LS3 valve into these LT1 heads and see what happens. They are 10g lighter and would provide probably another 10-15cfm down low. They fit on the stock seats as well. Would be a curious test to see what they would do.

The point is to keep the port as small as possible cross section wise with the correct taper and a bunch of velocity, tumble and swirl.

What about GMs CNC ported heads?

[PRAY]

Originally Posted by Richkidd87

What about GMs CNC ported heads?

In the past they have not been worth it at all. I will say that their CNC LS9 heads with a little extra work are a good product.