BBC steel head comparison

[scottcleaver]

A little midnight contemplating. Rebuilding a 1990 454SS truck engine. *I will not be rebuilding it to its original 230hp version. I hope to build a 450-500 version. Given that the truck will need to be street friendly, adequate brake vacuum, run on crappy 87 octane gas and really just be a calm cruiser, I have compared two sets of factory heads as well as aluminum heads. For this comparison I want to stick to the factory steel head options due to price. A set of 049 heads versus the vortec L29 heads. I will get the correct piston for whichever head i choose as I don't want to be over 9.0 to 1 compression. I know there will be a ton of additional variables like cam, intake, headers, gearing, converter and others but I really want to just talk about the heads. Which head would you go with if it was made available to you?
Thanks
Scott

[scottcleaver]

A couple compression theories. the 049 head at 113cc and the Vortec L29 head at 100cc.

[bobmc]

modern chamber design and flat top piston for me, are you going to have some kind of computer control for this build?

[mag2555]

The 049 heads should serve you well and if you run a Cam of even just .500" lift with what they flow should have you making 450 hp.
Your Cam pick in regards to the overlap and center line could add or subtract 20 to 30 hp from that 450 hp number!

[Schurkey]

I want to stick to the factory steel head... ...A set of 049 heads versus the vortec L29 heads.

1. A steelhead is a fish.
2. I took L29 Vortec heads OFF, so that I could install older, Mk IV oval-port heads. They weren't 049s, but they were similar.

[77cruiser]

I want to stick to the factory steel head... ...A set of 049 heads versus the vortec L29 heads.

1. A steelhead is a fish.

Cast iron heads.

[mag2555]

A Steelhead is a west coast version of a Atlantic Salmon, no?
It also seems that the L29 heads heads are down a minimum of 20 cfm between 400" lift and 550" as compared to the 49 casting.
Just that alone will make for a minimum 5 hp per cylinder difference for a total minimum loss of 40 hp!

[PackardV8]

FWIW, scottcleaver, when a customer asks for:

1. 500 hp from a 454
2. don't want to be over 9.0 to 1 compression.
3. run on crappy 87 octane gas
4. street friendly, adequate brake vacuum, . . . and really just be a calm cruiser,
5. stick to the factory steel head options due to price.

My answer is, "Call David Vizard. He knows how to do those better than we do and better than the GM engineers; with the same goals as you have, they could only get 230 horsepower." And that's actually a sincere compliment to DV; when he does this type build, it seems easy to reconcile all those conflicting requirements and still make the horsepower.

BTW, what's the budget for this build?

[strokersix]

Packard, I must take exception to your comment.

"He knows how to do those ... better than the GM engineers"

I mean no disrespect. GM engineers have a different set of constraints to work within.

I am an engineer, retired from a major AG equipment OEM so I do have some perspective.

[PackardV8]

Packard, I must take exception to your comment.

"He knows how to do those ... better than the GM engineers"

I mean no disrespect. GM engineers have a different set of constraints to work within.

I am an engineer, retired from a major AG equipment OEM so I do have some perspective.

Agree; my point exactly, but since it's a given humor/irony doesn't communicate well when broken into bits and bytes, I should have long ago learned not to go there. Someone will always read it literally.

Agreeing with you again on the same topic but different, many of the Ram/Cummins guys up here installed "Bully Dog tuners" and bragged about how much improved economy and power they got. My answer is, "Then you're saying you bought an engine designed and tuned by incompetents. They could that easily have given you all that power and mileage, but either didn't know how or chose not to. Of course, there could be a downside with durability, warranty or emissions Bully Dog isn't telling you about."

Derive Systems was apprehended by the Environmental Protection Agency for selling tuners under their SCT and Bully Dog subsidiaries that were in violation of the Clean Air Act. 330,000 units are claimed to be in violation. In addition to paying the $300,000 penalty, the company must spend an estimated $6.25 million to bring their products up to snuff.

[pdq67]

I thought the old -049 head varied from like 113 to above 118 cc's chamber volume so you had to cc them to know for sure.

As for a small chambered head, hunt up a pair of old -206, "bathtub", shaped closed chamber heads because they should be down around 96.7 to 98 cc's chamber volume and are true large oval intake port. (I have a pair in my garage)..

I mention this because the L-29 heads intake ports even though large oval are only about 130 cc's or maybe a skosh bigger vs the regular old large oval heads up around 155 to 160 cc intake ports. Might wanna cc everything to know for sure...

Another head worth considering is the old, "smogger", that have the exhaust valve quench, "square cut", even with the intake valve. These generally run around 113 cc's and way un-shroud the exhaust valves! Also true large oval heads. Way open chamber quench heads..

pdq67

[Carnut1]

https://www.google.com/url?sa=t&rct=j&q ... c3kLSdH6SY

I would like to see this project get together with a worked up set of ported peanut heads. Thanks, Charlie

[pdq67]

Charlie,

Mark does a great -236 head, but I don't by any stretch think the intake ports are down around 195 to 200 cc's like stock PP heads vs the L-29's at say 130 to maybe 135 cc's or so IF I have this right, please check me here. Almost all stock large ovals are generally like 155 to may be 160 cc intake port sized..

I might still have OR had a mag article where they compared the new L-29, 454, P/U engines heads to the old 454 PP P/U engines heads and there was no comparison due to the 100 cc heart-shaped, fast-burn chambers of the L-29 head vs the something like 113 cc's or so standard chambered large oval head.

And I am NOT taking anything away from Mark because earlier John L. did a couple of tests (in two different mag articles), years ago using a 496 and later a 502 both starting out as lo-po, reworked PP headed, P/U engines turned Hi-PO with more cam and better reworked heads. One article is in the mag that has, "Chezoom", on the cover! CR stayed the same all through the tests. I want to say like 9.2 or 3 to 1 CR?? I want to say his 1st cam was a CC 252HE(??) for P/U or tow-truck engine use..

I bought my, "swap meet", -206's that should be down around 96.7 to 98 cc chamber size to play with using a stock mid '70's P/U 454 along with just .020" thick steel shim head gaskets to try to up their TERRIBLE about 7.9 to 8 to 1 CR so that a decent cam could be used to up Hp and T. I think if I remember right, I could get up to like 9.2 or 3 to 1 CR??? Therefore a cam like a CC 268HE, (218 @ .050), could be used vs a stock cam at like 198/198 @ .050 or so?? Sorry, I forget??

I never got any farther along than wishing on this project..

pdq67

[travis]

Charlie,

Mark does a great -236 head, but I don't by any stretch think the intake ports are down around 195 to 200 cc's like stock PP heads vs the L-29's at say 130 to maybe 135 cc's or so IF I have this right, please check me here. Almost all stock large ovals are generally like 155 to may be 160 cc intake port sized..

I might still have OR had a mag article where they compared the new L-29, 454, P/U engines heads to the old 454 PP P/U engines heads and there was no comparison due to the 100 cc heart-shaped, fast-burn chambers of the L-29 head vs the something like 113 cc's or so standard chambered large oval head.

And I am NOT taking anything away from Mark because earlier John L. did a couple of tests (in two different mag articles), years ago using a 496 and later a 502 both starting out as lo-po, reworked PP headed, P/U engines turned Hi-PO with more cam and better reworked heads. One article is in the mag that has, "Chezoom", on the cover! CR stayed the same all through the tests. I want to say like 9.2 or 3 to 1 CR?? I want to say his 1st cam was a CC 252HE(??) for P/U or tow-truck engine use..

I bought my, "swap meet", -206's that should be down around 96.7 to 98 cc chamber size to play with using a stock mid '70's P/U 454 along with just .020" thick steel shim head gaskets to try to up their TERRIBLE about 7.9 to 8 to 1 CR so that a decent cam could be used to up Hp and T. I think if I remember right, I could get up to like 9.2 or 3 to 1 CR??? Therefore a cam like a CC 268HE, (218 @ .050), could be used vs a stock cam at like 198/198 @ .050 or so?? Sorry, I forget??

I never got any farther along than wishing on this project..

pdq67

I think you need to replace a bunch of your 1’s with 2’s. 130, 155, and 160cc is stock sbf and smogger sbc territory.

Don’t L29’s have a non adjustable valve train too?

[strokersix]

Packard, I do now see the humor/irony in your comment. Sorry I took it literally.