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540 BBC Street Heads

Posted: Mon Feb 16, 2009 11:36 am
by 35window
Good Morning everyone,

I have Posted here a few times before with some ignorant questions (I mostly lurk), and I do realize this is primarily a Race Forum, however there is so much knowledge here I thought I'd ask a few questions (if you will indulge me):

I am building a Street Rod, and had started with a 454 Gen VI-that quickly became a 496 when I purchased a complete 4.25" Rotating kit from Eagle (4340, 6.385 Rods w/L19)-

My goal has been a nice running quicker Car that is streetable, not a big handful that I will hate to drive, and I realize that a 540 is plenty big for the street. I am looking for something around 600 h.p. as I know at even that level it's too much for the street (although I know that most people will say there is never too much).

I'm afraid that I am losing control here, as I just purchased a new 502 GM Block (p/n 10237292)-now I am looking at a 540, and I have already purchased a set of Edelbrock Oval port Heads for the 496 (p/n 6045-290 cc)-they will fit the 502 Block. I know that people always say to buy a Dart Block, but this is only for the steet, and I believe this Block is enough (I think :lol: ).

So, here is the question-I have always been told that if you want good street manners to have Oval port Heads (for velocity). This Car will see a majority of it's life below 5000 rpm (it IS a street car)-so, would it be better (and maybe cheaper?) to send out my Edelbrock Heads for porting or buy new Heads? If the consensus is for new Heads (keeping in mind my goals) which ones are best (there doesn't seem to be many big cc Oval Port Heads available)? And, if porting seems to be the best bang for the buck (it appears to be needed), who to send them to and approximate cost? What Cam would be best for my combo?

Thank you in advance for your comments, it is very much appreciated! :D

3000# Car
29.5" tall tire
4L80E or built 700R
3.55 9" (Four Bar)

Posted: Mon Feb 16, 2009 1:30 pm
by 63 Nitrous Ratt Vette
It looks like you have your toe in the water.....so to speak. Truthfully what you are looking to build belongs in a tow truck, not a street car. A 5000 rpm street car with a 540 would be a miserable ride, lots of tq and then it would fall on its face. Get rid of those heads, get some AFR 315's or simliar head and go to work. Those little Edelbrock ovals belong on a 454, not a 540.

A 540 wants to breath and rpm a bit. You want the thing to have some legs, otherwise power comes on all at once and goes away just as fast.

Posted: Mon Feb 16, 2009 2:27 pm
by 3V Performance
I would have to disagree. I think with 600hp goal the Edy oval port will handle this with not breaking a sweet and all below 6000rpm on a 540.

Yes more port work or bigger heads will heald bigger numbers but not needed for this kind of build IMO.

Finish what you have with nice hyd roller in 245-250ish range and have fun.

Posted: Mon Feb 16, 2009 7:10 pm
by jdavis
I agree with 3v. Should be able to accomplish 600hp with a 540 like falling off a log.

63 Nitrous Ratt Vette; I dont believe he meant saying below 5000rpm I think he meant MOST of the time he will be below there.

I would be tempted to put a single plane on it and a goodly sized carb to feed it when it gets wound up though, probably go for a carb from troy at tmp carbs who posts here. I have talked to a few guys about his work, he really can make rather large carbs work real well on the street etc. Some may disagree with the single plane crying about low end torque, but believe me with 540 inches you got it covered and then some you gotta try real damn hard to take tq away from that size motor built for lower rpm use.

I would also use a 3" exhaust setup, 2.5 is for weak suck small blocks.

Posted: Mon Feb 16, 2009 7:11 pm
by jason snyder
I agree with you both ! 63vette i know what you mean by instant torque,then nothing ! basically he will murder the tires before he even gets out of his own way !!!

and 3v , i agree his edelbrocks are perfect for his 600hp goals ...

So with that said dont you think he could cam it up a bit and run it .

Posted: Tue Feb 17, 2009 8:42 am
by 35window
Thank you all very much for your replies! I had already purchased an Air Gap for the 496, so I guess I'll have to sell it- :(

So, if I should get an Intake, which would be the best-Dart? Victor? Dominator Carb? I'll bet to most this seems like a mismash of Parts.

jr, I had already decided on the 3" Exhaust, thank you for validating that. After I posted yesterday I went Googling (is that really a word?) and found a 540 build with a Brodix 294cc Head-maybe this is close to what I could expect?http://www.chevyhiperformance.com/tech/ ... index.html

As for Cam, I will go with what you suggested 3V-Comp shows a XR300HR Grind (.248-.254-with .560-.580 lift-114 lsa)bad choice? I am at 45-5000' elevation-

Again, thank you to all-I appreciate your responses and knowledge-

Posted: Tue Feb 17, 2009 8:55 am
by Horndog
Those Edelbrock oval port heads will fill the bill nicely in stock form or if you have them ported. If you go the later route, be sure to get them into the hands of an experienced porter. Good idea to have the intake ported (port matched) along with the heads. I do agree with jdavis that it going with a single plane intake would help kill some low-end grunt. If you decide on a single plane, a Edelbrock Victor Jr (for a 4150 carb) would be a great choice. Since this is a pump gas engine, a true compression of 10.5 to 10.75 will be sweet.

For a cam, I'd opt towards a hydraulic roller with .050 numbers in the 250-260 range.

You're going to have plenty of torque on hand so it may pay to use shorty headers to help kill some of that low-end grunt. I'm not a big fan of them but they do have some uses in certain cases.

Regarding the trans, use the 4L80E over the 700R4. The 4L80E is really a 400 turbo with overdrive. It has a much better gear spread and is a much more durable unit compared to the 700R4.

Another option over the 4L80E trans is a 200-4R. These are non-computer controlled transmissions and can be built to withstand 1500 plus HP. It also has a much better gear spread Vs the 700R4.
Art Carr is the man on the 200-4R: www.cpttransmissions.com

Posted: Tue Feb 17, 2009 9:11 am
by cboggs
I think you've chosen a great head for a street rod build, .. Edelbrock makes
some very nice stuff, .. and that head is perfect.

Porting, I don't think you need to, .. you'll reach your power goals
with no problem, .. so why waist the cash, .. use it to get gas for cruzin'

As for the "oval" port thing, .. I gotta say this as it's a pet peeve, ..
Oval ports are more of an application specific thing, . and has really
become a fad blown WAY out of proportion.

Good velocity profiles are VERY important, .. and large corner radious
in a port can help that, .. but just because it's an oval port doesn't mean it's right.

But, in your case it IS right, .. just felt like going off on a little "rant" this morning.

Thank you for coming, please exit to the left, ..

Curtis

Posted: Tue Feb 17, 2009 10:10 am
by 67RS502
If you want good street manners stay mild with the cam, and let the heads and intake
make the power. If I was doing a 540 I’d go with a bigger rect. head just because it would
leave you room for more power down the line, but your oval ports will make 600hp with ease.
Just consider wanting 700 or 800hp later down the road.

Posted: Tue Feb 17, 2009 8:01 pm
by jdavis
67RS502 very true. With some mid sized afr rectangles 700-750hp should not be a problem with a decent sized solid roller and still be streetable enough. I just have this hunch he wants more of a cruiser that he can depend on than a bruiser :lol:.

The oval port thing being the king on the street is a bit of a suggestion that got way out of whack imo. You have to look more at the volume of air the port is capable of moving and its cross section to determine its velocity on paper. The problem there is that in real life the air is not flowing evenly through the port and there are dead places or low velocity places. If there are dead places like say the corners of some rectangle ports they cant hurt you and adding material there in all likelyhood will not gain you anything unless it was storing fuel droplets and throwing the tuneup off at random or causing oddities in the direction of airflow. Anyway the point is dont get yourself too hung up on classical hotrod wisdom. I agree entirely with what Curtis has told you, you're good to go here.

For the cam I would defer to one of the very good camshaft guys we have as members here. Either talk to CamKing or to UDHarold. Either of them will nail it down pretty good. I really like what I have seen of Harolds work lately he has some lobes that have very gentle ramps and still make plenty of power, makes for a nice quite valvetrain. Camking may be ideally suited for this build though he likes alot of rocker arm which you need unless you want to spend alot of cash on lifters for the gen 6 block.

One place I would spend money is to have the intake manifold worked over if you do get something like a vic jr etc. That generally is a simple painless 25-30hp and not very costly. Consult your porter on what they like to work with and what works for them to keep porting labor costs to a minimum, curtis is good (dont know if he does intakes though?), so is dennis at afd, and so is mr meaux (maxracesoftware).

The aboslute worst thing you can do when it comes to a large motor like this if you're not experienced with them is to underestimate in any way what it takes to get the job done. Even with a low lets say 6000rpm limit the requirements are far greater than a common 454. If you miss one thing eh you might still be ok but miss two or three and you got a boat anchor.

Sorry for the bit of rambling, I think its applicable though.

Posted: Wed Feb 18, 2009 10:20 am
by 35window
Wow!

I was hoping for a few replies and got the motherlode! Thanks to all. I know it would not be too hard to get 700 h.p. out of a 540, but really, I think it's all just tire smoke above 500 h.p. on the street anyway, so why bother?

As for a good porter (for the Intake), jr, sorry for my ignorance, but who is curtis, dennis at afd, and mr meaux (maxracesoftware)? How do I get in contact with them? I have read about DrJ's in the EMC Magazine, but really don't know who is the best for this type of work.

As for the Oval vs. Rectangle Head debate, I learned something, however I could understand the reasoning behind the Oval theory-guess it's debunked. Thanks for the education!

I have watched the Cam King and UDHarold, and I agree, from what I have seen here (and other sites)they are both very good. I will contact them.

"The aboslute worst thing you can do when it comes to a large motor like this if you're not experienced with them is to underestimate in any way what it takes to get the job done. Even with a low lets say 6000rpm limit the requirements are far greater than a common 454. If you miss one thing eh you might still be ok but miss two or three and you got a boat anchor. "

That is my biggest worry-if I had needed to buy the AFR's and whatever else I will gladly do it, I don't want a "Boat Anchor", and I realize my combination of parts isn't optimum. However, I have heard of guys who had to have 800 h.p. on the street, and then realized what the beast really was and then took steps to detune it-I'm just trying to be realistic (and trying to keep my Driver's License :D ).

Posted: Wed Feb 18, 2009 12:30 pm
by jdavis
Curtis is cboggs who replied earlier, and does some fine work http://www.raceflowdevelopment.com/.
Dennis is on here as airflowdevelopement I believe .
Larry Meaux is on here as maxracesoftware http://www.maxracesoftware.com/.

All extremely reputable porters and members here. For Dr J, I just have trouble with the whole knife edging of runners I have seen it go the wrong way a couple of times with locals trying it thinking that a sharp edge would improve flow, and watching .3 add onto thier track times. If it works for him I am glad, that has not been my experience.

As another note, your carb will likely need a bit of special attention when it comes to selection there. If it were me I would just have one built from scratch. I have been thoroughly unimpressed with the quality I have seen of late on shelf carbs. Also a 750 or 850 holley is really nowhere near getting it done for your airflow requirements. It is possible to have some fairly large size carbs made in the 4150 style rather than going to a dominator.

Posted: Wed Feb 18, 2009 12:51 pm
by 35window
jdavis,

Thanks so much, I want ot support this Forum so I will contact one of these gentlemen. Curtis was very forthcoming, and I appreciate that very much.

I have no qualms in having a Carb built specifically for this application, and that was the plan-sounds like TMP might be the ticket.

I really do appreciate everyone's insight, this is not something I do every day (just building a Street Rod from scratch has been an eye opener), so again, thanks to all! :hello2: :notworthy:

Posted: Wed Feb 18, 2009 1:16 pm
by cfm
Is the 496 still alive ? This will should get to 600hp with the Eddy heads and good HR cam, no? I understand the attraction to the 540, but since it hasn't been built yet I figured I'd ask about the 496.

Posted: Wed Feb 18, 2009 1:22 pm
by airflowdevelop
I personally wouldn't "try" and make power below 5k rpm... with the large displacement... and tight induction system you will end up with a gas powered diesel... Have watched many people build dishearting tug boats...getting caught up in the street car needs all the power it can make at low RPM... Magazines have punished intelligent people with all this low lift flow / small ports / 2000 RPM TQ bs!

So If I disect your post... I think what you are really saying is:

1. I want a driver... Plenty of power for cruising and part throttle passing.
2. Please give it some manners... I don't want to feel like Jason Line when sitting at a stop light.
3. When I hit the loud button... I want it to go like a greased pig on plexiglass... Keep the power coming until 6500...

If this isn't what you are thinking... disregaurd the rest of my post.

Your recipe..
1. You CAN make the edie ovals work for your combo...they will need a fair amount of work to get enough CSA.
2. Your porter AND your camshaft guy must get along...and explain to them what you REALLY want. If both guys are doing there job...they will deliver it.
3. As someone else pointed out... your intake manifold is VERY important.. especially since no one tends to pay attention to Oval port intakes. Spend some money here.

Thanks
Dennis