Peanut vs Oval port, velocity, etc.

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1980RS
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Re: Peanut vs Oval port, velocity, etc.

Post by 1980RS »

Welcome, here are 2 different set of peanut port heads I have used in the past few year.
Casting 236's 2.06 intake valves, 1.72 exhaust, mild ported
Best time, 11.70's@112mph, in 2019

Casting 360's 2.19 intake valves, 1.88 exhaust valves lot more porting.
Best time 11.16@119mph this past May

Both sets of heads were run on the same flat top piston .030 454 engine, with small tube headers and a variety of intakes and carburetors.

I did run one set of 215 closed chamber heads with the big valves in them with pocket porting, they were no better than the 236 pp heads.
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Re: Peanut vs Oval port, velocity, etc.

Post by i82much »

I guess I figured the peanut port would actually be ahead of the Edelbrocks at 3200 rpm, especially with such a small cam. But not even close.

Another thing i find odd is that I think the zz502 has the same heads as those Edelbrock heads in the article I linked. And the zz502 is rated at 502 HP, I’ve seen some internet discussions suggesting they dyno a little better, maybe 515 or 520 HP.

So a 496 with peanut ports (from the article) and a fairly similar cam makes as the zz502 makes just as much power as the 502. But the 502 has a bigger bore and Edelbrock heads!

The same 496 makes 60-80 horsepower more than the zz502 when you put the Edelbrock heads on it? I know there is always noisy data and you can’t directly compare, but still, that seems like a big difference!
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Re: Peanut vs Oval port, velocity, etc.

Post by Dragginwagon406 »

i82much wrote: Fri Nov 26, 2021 9:36 pm I guess I figured the peanut port would actually be ahead of the Edelbrocks at 3200 rpm, especially with such a small cam. But not even close.

Another thing i find odd is that I think the zz502 has the same heads as those Edelbrock heads in the article I linked. And the zz502 is rated at 502 HP, I’ve seen some internet discussions suggesting they dyno a little better, maybe 515 or 520 HP.

So a 496 with peanut ports (from the article) and a fairly similar cam makes as the zz502 makes just as much power as the 502. But the 502 has a bigger bore and Edelbrock heads!

The same 496 makes 60-80 horsepower more than the zz502 when you put the Edelbrock heads on it? I know there is always noisy data and you can’t directly compare, but still, that seems like a big difference!
I’m not familiar with either build, nor testing configurations, but assuming the values are corrected to the same standard, the build or testing details must be hiding that much difference.

Here’s a good PP thread.

https://www.chevelles.com/threads/454-p ... ds.391179/
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Re: Peanut vs Oval port, velocity, etc.

Post by i82much »

so here’s another wrinkle i don’t get. i looked at 3 GM crate engines - HT502, 502 HO, and ZZ502.

HT502 makes sense to me - little baby cam and peanut port heads, 406 hp.

zz502 kinda makes sense - modest cam and modest “roval” port heads, 502 hp.

502 HO makes no sense to me - big old rectangular port heads but a smaller cam than the zz502, 461 hp?
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Re: Peanut vs Oval port, velocity, etc.

Post by Alaskaracer »

Different builds on the same platform. Cam different, heads different. Can't compare them to your build either, different bore and stroke than your setup. Honestly, I think you're starting to stray away from your original ideas....Also, cylinder head technology has changed considerably even over the last few years....the peanut port heads are junk if you want my opinion. They had a purpose and that was served more than two decades ago....just like the 781 and 049 heads....they may work, but are old.....very old....I won't run stock heads on anything unless it's just a stock rebuild or a rules restricted class and there isn't an option. There are plenty of aftermarket heads out there that will walk all over the top of any of those out of the box, and some for a similar price to those if you had them ported and updated.

Here's my final piece of advice, same as I mentioned before. Call a few different QUALITY head porters and talk to them. Be VERY honest about your build and intentions. See what they have to say. One I can recommend is Chad Speier. He's VERY good, and will give you great advice. He won't try to sell you something unless you ask to buy from him.


I think something else you're missing on those builds is you're only looking at hp. Not torque, not rpm at which hp peaks, etc. Those tell a very different story between the combos...Cam selection will also be critical....Don't think in terms of a "small cam", because you may be leaving power on the table. People misunderstand cams more than a lot of other things. I've tried to use the most lift I can get within reason, and match the duration and lobe separation and centerline to the rpm range I want. Something else to consider is compression. There is power in compression and when not excessive, can make significant differences. One thing I forgot to mention as well is combustion chamber size and shape, with shape being the big one. Chamber shape can have a significant effect on engine power output. Newer chambers are fast burn, require much less timing than older designs, and improve overall combustion.
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Re: Peanut vs Oval port, velocity, etc.

Post by prairiehotrodder »

i agree with colorado racer. I'd also like to add something to consider from i financial standpoint. Bringing old iron heads back to life is exspensive. Especially if you use all new parts and done correctly you will be 3/4 of the way to some brand new aluminum heads. I've done it. Also there is the concept of buyers remorse. This happens when you spend good money on cheap junk. It never happens when you spend even more good money on high quality parts that are what you really wanted in the first place.

The PP heads can go fast as some racers on this forum have proved. Just like a 305 chevy can go fast if you really want to. But a 350 will be even better.

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Re: Peanut vs Oval port, velocity, etc.

Post by i82much »

I appreciate all the responses. I'm just feeling around for information to get a sense of my options. I've considered everything from just upgrading to a hyd roller in my current 396, trying my hand at a basic rebuild on a core 454 from craigslist, having a professionally-built 496, to even an aftermarket block and building a 540.

A 496 with 781's or 049's does seem like the sweet spot for a nice truck engine with some snap without going overboard. I think I've pretty well convinced myself that peanut ports are something I might try if I build an engine myself just to learn something, but not something I'd sink much money into.

I would love to see someone take a zz502 and 502 HO and stick a 250@.050 solid roller, single plane intake, and double pumper on each just to see if those iron rectangular ports on the HO would beat out the aluminum heads on the zz502. Kinda weird that Chevy puts the bigger heads on the HO. My guess is that decision is less about engineering and more about marketing and cost - I would imagine Chevy has to pay Edelbrock a lot more for the zz502 heads than their own iron rectangle port heads for the HO cost them. And the zz502 being a spendier option might sell better with the bling-bling aluminum heads.
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Re: Peanut vs Oval port, velocity, etc.

Post by i82much »

prairiehotrodder wrote: Sat Nov 27, 2021 12:29 pm i agree with colorado racer. I'd also like to add something to consider from i financial standpoint. Bringing old iron heads back to life is exspensive. Especially if you use all new parts and done correctly you will be 3/4 of the way to some brand new aluminum heads. I've done it. Also there is the concept of buyers remorse. This happens when you spend good money on cheap junk. It never happens when you spend even more good money on high quality parts that are what you really wanted in the first place.

The PP heads can go fast as some racers on this forum have proved. Just like a 305 chevy can go fast if you really want to. But a 350 will be even better.

Brian
That kind of reasoning makes sense to me! I like the idea of either building my own cheap 454 - peanut ports, hyd flat, stock crank and rods, cheap pistons - just to try building my own engine. Or get a 489/496 built professionally with good heads. I doubt I would exceed the limits of a cast crank, 5140 rod, hyper rotating assy, but I'd do a 4340 crank and rods and 4032 pistons anyway for the reasons you state. That way, if i want to go fast later, I already have a good short block and even if I stay mild I have peace of mind.
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Re: Peanut vs Oval port, velocity, etc.

Post by Alaskaracer »

For the right price, I'll sell ya mine........
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Mark Goulette
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Re: Peanut vs Oval port, velocity, etc.

Post by i82much »

Coloradoracer wrote: Sat Nov 27, 2021 5:33 pm For the right price, I'll sell ya mine........
sorry, but ... i don’t like blue :mrgreen:
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Re: Peanut vs Oval port, velocity, etc.

Post by Dragginwagon406 »

For me, it makes sense to rework the factory castings. I would feel differently:
  • If I didn’t have a skilled performance machinist nearby
  • if I didn’t have VortecPro videos to work from
  • If I didn’t want to control the component quality used in the build
  • If I didn’t enjoy knowing what makes it tick, and why
  • If I couldn’t do the porting myself
  • If it wasn’t fun showing someone what is possible with factory iron
  • If I didn’t want to save about 1/2 of new
1.87, 11.72 @ 120, 4110 lbs, 2.56 gears, stock stall, 225/70-15 Cooper Cobras
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Re: Peanut vs Oval port, velocity, etc.

Post by i82much »

i am about to pick up some cooper cobras for my 505 CID 65 GTO, i should prolly hit ya up for some ideas on how you ran 11’s on those tires!
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Re: Peanut vs Oval port, velocity, etc.

Post by rfoll »

i82much wrote: Sat Nov 27, 2021 1:37 pm I appreciate all the responses. I'm just feeling around for information to get a sense of my options. I've considered everything from just upgrading to a hyd roller in my current 396, trying my hand at a basic rebuild on a core 454 from craigslist, having a professionally-built 496, to even an aftermarket block and building a 540.

A 496 with 781's or 049's does seem like the sweet spot for a nice truck engine with some snap without going overboard. I think I've pretty well convinced myself that peanut ports are something I might try if I build an engine myself just to learn something, but not something I'd sink much money into.

I would love to see someone take a zz502 and 502 HO and stick a 250@.050 solid roller, single plane intake, and double pumper on each just to see if those iron rectangular ports on the HO would beat out the aluminum heads on the zz502. Kinda weird that Chevy puts the bigger heads on the HO. My guess is that decision is less about engineering and more about marketing and cost - I would imagine Chevy has to pay Edelbrock a lot more for the zz502 heads than their own iron rectangle port heads for the HO cost them. And the zz502 being a spendier option might sell better with the bling-bling aluminum heads. The fact that you have a 396 in the truck already brings up thoughts about something I did recently. I had a decently built 402 in my C20 tha I use for towing the race car, boats, and hauling a big camper. I served its purpose, but I wasn't overly exited about the results. I swapped in a 400 with Vortec heads from another project and never looked back. It removed a huge chunk of Iron from the nose of the truck, immensely improved torque in the critical 2000-3500 rpm range and picked up 2 mpg. I then sold the 402 from the truck and sold my 402 spare for $1000 each. So the question is, Are you really looking for better low end torque?
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1980RS
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Re: Peanut vs Oval port, velocity, etc.

Post by 1980RS »

In all my years of racing nothing has made me happier than when my no compression 461 ran 11 teens this year with a set of "no one wants these" truck heads in 80 degree heat. Just goes to show that what people sometimes call junk can turn out to be a diamond in the rough.
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Re: Peanut vs Oval port, velocity, etc.

Post by mt-engines »

1980RS wrote: Sun Nov 28, 2021 8:01 pm In all my years of racing nothing has made me happier than when my no compression 461 ran 11 teens this year with a set of "no one wants these" truck heads in 80 degree heat. Just goes to show that what people sometimes call junk can turn out to be a diamond in the rough.
The problem, is too many people listen to the people that talk the most but work the least.
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