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Stroked Z28
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Discussion Starter #1
I picked up my 383 short block today. This is a 3600 lb STREET car shooting for 385 or so HP. This car will occasionally see 6500 RPM's when nobody is looking... Can I please get some feedback on my top end (nothing purchased yet):

Dart Iron Eagle Platinum Heads (64 cc / 215 intake runner - 10.3:1 or so CR)
Victor Jr Intake
Holley 750 CFM
Roller rockers (1.6 ratio)
1 7/8 headers into 3" collector into 2.5 exhaust

These things will NOT change:
cam LSA 112*, 218* intake / 226 exhaust at 0.050" (278*/284 advertised)461/.468" lift --- the cam looks wimpy, but it has a steep ramp that helps...
3.73:1 gears behind my TKO 600

Thanks!
 

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Save a horse, Ride a Cowboy.
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Big Mouse said:
I picked up my 383 short block today. This is a 3600 lb STREET car shooting for 385 or so HP. This car will occasionally see 6500 RPM's when nobody is looking... Can I please get some feedback on my top end (nothing purchased yet):

Dart Iron Eagle Platinum Heads (64 cc / 215 intake runner - 10.3:1 or so CR)
Victor Jr Intake
Holley 750 CFM
Roller rockers (1.6 ratio)
1 7/8 headers into 3" collector into 2.5 exhaust

These things will NOT change:
cam LSA 112*, 218* intake / 226 exhaust at 0.050" (278*/284 advertised)461/.468" lift --- the cam looks wimpy, but it has a steep ramp that helps...
3.73:1 gears behind my TKO 600

Thanks!
:welcome:
You say street/fun car not race car.

I recommend you get a copy of "Hot Rod (magazine) Engines" issue Fall 2006, a special issue on the newstands NOW until end of February. A special HotRod do-it-yourself-series magazine.

On page 20 is a story "500 hp For Cheap". A Joe Sherman built pump gas 383 with single plane intake, RHS IRON heads. This might be more radical than you want though.
******************************
If you want something more street livable, I suggest your taking some of the money and maybe up the cam....... use EngineQuest Vortec iron heads that flow 230/160 @ .500 lift, Edelbrock dual plane Air Gap intake, and step up the cam to about a 230* single pattern cam on a 108 LSA with as much lift as you can find, even 1.6 rocker arms, and get into the .550 lift area. Here's an

example=

Popular Hot Rodding magazine did a Steve Dulcich buildup called "Budget Sledgehammer" on an iron head, dual plane intake, 350 Vortec that did 447 hp for $ 3500. It appears RIGHT NOW on the stands as an attachment to their current issue in plastic wrap.

This identical set up with the same cam on a 383 will make gut-busting 400 lbft torque at 2500 rpm with peak of 480, and with hp in the high 480+ range, run power brakes, and put a smile on your face that won't wipe off for months. :thumbup: That is what I would do. :D :cool:
 

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http://teamrfc.gospelcom.net
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The heads are too big. In order to have a motor that performs well, the parts need to be matched to the same powerband. Since you have choosen that cam, it would be best to match the rest of the parts to where that cam will make its best power. As a comparason, the comp xe262h is 218 224 @.050 .462 .469 lift 110 lsa is almost identical to yours and has a recommended powerband of 1300-5600 RPM. In order to get a head to match this range well, you will probably want an intake runner around 170-180cc. From here there are a couple of heads I would consider. The platinum dart heads are nice, but they are expensive, and I think you would get similar performance out of a set of Vortec heads. The reason for this is the lift of your cam. With 1.6 rockers, your cam will have .491 .498 lift. At and below .500 lift, the Vortec heads perform very well, to the point that they probably outflow the darts below ~.400 lift. The main drawback to the Vortecs is that they are a thinner casting than the darts. If they are severly heated up, they will crack easier. On the other hand, I had a set of them on a 355 that was overheated regularly; they were sonic tested and showed no cracks. Also, the victor Jr intake is designed for a much higher RPM range also (3500-8000). I would use the performer RPM (1500-6500). I had that intake on my motor and it ran very well. As far as headers go, I think 1 7/8" is a little big. I had 1 5/8" and liked them a lot. Below are a couple of prices and a dyno of a motor similar to yours.

Platinum heads 200cc. I could not find 180's I dont know if they make them in that size. $1,040.
http://www.jegs.com/webapp/wcs/stores/servlet/product_10001_10002_756811_-1_10187

This is a set of the vortec heads upgraded to handle .525 lift. It looks like they are only $340 a set. That is cheaper than I thought. Keep in mind that you will need a vortec intake and self aligning rocker arms.
http://www.sdpc2000.com/catalog/353...olet-Cylinder-Head-w-Valve-Spring-Upgrade.htm

Here is a dyno of a 355 that would be very similar to your 383 if you used the vortec heads.

355
9.4:1 compression
Vortec heads
xe262h with 1.6 rockers
performer RPM air gap intake

422 hp @ 5600 RPM
451 ft lbs @ 4200 RPM

http://www.popularhotrodding.com/enginemasters/articles/hardcore/0511phr_vortec/index1.html

I think can get an idea of the power these heads can make. Also, this was a 355 and you are using a 383. In a heavy car, you need torque, and I think you would probably be around 475-500 ft lbs in a 383.


Adam
 

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EngineQuest Vortec iron heads are aftermarket with thicker decks and significantly better flow than the factory Vortecs.
And seveal hundred dollars cheaper than the heads you are looking at.


edited:

Lots of people on this site "DIS" magazine articles and writers,

but Joe Sherman and Steve Dulcich are top engine builders in the USA and two of the nicest guys you'd ever talk to. I trust them and I'd follow their examples.
 

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http://teamrfc.gospelcom.net
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As Xntrik said It looks like the Engine Quest heads are around $640 a set which is still way cheaper than the Darts. One other thing to think about is the compression 10.3:1 may be a tad high for pump gas with iron heads. Some people say they have done it and had no problems though.

Engine Quest heads
http://www.eqcylinderheads.com/performance.html#chevy1
 

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firestone said:
As Xntrik said It looks like the Engine Quest heads are around $640 a set which is still way cheaper than the Darts. One other thing to think about is the compression 10.3:1 may be a tad high for pump gas with iron heads. Some people say they have done it and had no problems though.

Engine Quest heads
http://www.eqcylinderheads.com/performance.html#chevy1

:welcome: You might note that those heads were significantly milled to acheive that compression with the chosen pistons.

Like firestone, I would lean toward 9.5 if I were doing it. :thumbup: and expect a 2 % power loss. Worth it if I HAD to buy cheapo fuel.

What we always said was......."You can build a 420 hp engine with a fuel problem, or a 400 hp engine that will run on swill."
 

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Another Vote

What Xntrik and Firestone are telling you is gospel. I agree that 215 cc ports on a motor with this mild of a cam is too much. And in particular I think the headers at 1 7/8 would be overkill. And frankly, I think the cam for a street driven 3500 lb car is pretty good, not too little at all. I personally wouldn't change the cam. Maybe just a wee bit, but not much, IMHO. You should get great torque from a good set of Vortecs, or spend a little more and step up to a set of AFR 195s or AFR 180s, even. Not a lot more money than the heads you were looking at, but they allow a tad more compression and would likely flow a bit better (but I haven't checked out the iron heads you're discussing, either, so I confess to being kind of ignorant there). Lastly, the Victor Jr intake is overkill. Particularly for the street sort of motor I'd expect you'd want for a 3500 lb car. The RPM AirGap will support over 450 HP from a 383 without too much trickery. If you're looking for a little more high end, and don't mind giving up some bottom end, then the Victor Jr might be a good choice. It'll surely produce more HP on the top end, but I'm afraid you'd see some real softening on the bottom end.

Pat
 

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Race The Truck
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I agree Vortec heads, see the Super Chevy build from stock to 500HP they go through all the diffrent performance parts on a build so you can see what work and what does not.

Craig
 

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Stroked Z28
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Discussion Starter #10
Ok guys. This is exactly the feedback I was hoping for.

That combo was what my machinist suggested. He had me scared when he told me that without a big carb and the Victor Jr that I would lean-out on the top end :eek:

I believe my Q-Jet (Jet performance reman'd unit) is more than up to the task - especially with that cam. I also don't plan on hanging out above 6500 RPMS too often.

So, it looks like I'll tone down the intake runners, explore some other possible head options, and get an intake that will actually fit under my hood.

Thanks everyone. If I'm missing anyting, please let me know!
 

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Chasing dreams with a ball bat
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Just my $.02

The headers at 1 7/8 would be too big for the powerband of the cam you've picked. Big headers make better power upstairs but really do hurt the low end, unless you are running lots of cubes (406, 427, 434 etc.)

I forget what mag did the comparo, but 1 5/8 headers were the "best" all around headers on their 355.

I have a 355 that has Iron Eagle 200cc heads that were ported a bit by the builder, 10.5 SCR, a 228/228 @ .050 cam. She idles real nice and lots o power on premo pump gas.

Gotta make sure your quench is set up right to make it work. .040" is about right. That will help you make sure that detonation tendencies are minimized.
 

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techinspector1 said:
Upgraded GM Vortecs with 0.525" lift capacity can be bought for $680 COMPLETE. Doesn't $640 BARE seem a little pricey or is it just me?

GM Vortecs and EngineQuest Vortecs are NOT the same things. EQ are aftermarket rules-legal heads cast for the circle track IMCA cars.

The EQ 180 head flows 225/160 at .500 lift and keeps on gaining right up to .700. They will accept high lifts right out of the box, have screw in studs, etc. They are 4-500 cheaper than most aftermarket alum heads. Compared to AFR 180s = AFRs flow about 250/190 at .500 for much more $$. The EQ Vortecs even flow slightly better at very low lifts. 225+ will support at least 450 hp and maintain good torque down low for street driving.
 

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Big Mouse said:
That combo was what my machinist suggested. He had me scared when he told me that without a big carb and the Victor Jr that I would lean-out on the top end :eek:


know!

If that is exactly what he said.......

then he is .... uh....... mistaken...... :rolleyes: :rolleyes:


Word from somebody that has been around this since Chrysler invented the muscle cars....... "Just because someone can run a boring machine, or builds engines daily, doesn't mean that they know squat about picking combinations or tuning engines." X :cool:
 

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Race it, Don't rice it!
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Good point there



Dart have a 60/40 valve spacing and might shroud the intake with the 2.05 intake. If you use dart, Go with the 2.02 valve.
 

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I got to looking at the flow numbers on these heads, and it defanetly looks like those EQ vortec heads would perform well on a motor with a decient cam, but compared to some of the flow numbers I have seen for the GM vortec heads I dont know if they would perform as well in a low RPM street application where you have a cam with relatively low lift. I realize that there are many ways to effect flow numbers, but if you compare the numbers that CHP got for the GM vortec heads, it looks to me they may perform better in this application. What do you think?

EQ flow numbers:
http://www.eqcylinderheads.com/flow.html

GM Vortec Flow numbers from CHP
http://www.chevyhiperformance.com/techarticles/41598_cylinder_head_flow_bench_database/photo_14.html

This still does not address the cracking issue though. The only reason I bring this up is that I had a set of the GM vortec heads, and I loved them. I have no experience with the EQ heads, I just wondered what any of you thought about the information I found.

Thanks,
Adam
 

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Save a horse, Ride a Cowboy.
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Thanks for those links. saved :thumbup:

The EQs come in various sizes. Bench to bench comparisons are sometimes not 100% valid.

I suggest studying the articles in # 2 above.

If money were no object, :D then I guess we wouldn't be having this thread, huh. :D

Something I discovered years ago, ....... is....... in back to back dyno tests, lesser flowing heads sometimes make more power. :D

Headers, extension pipes, mufflers, accessories.... COMBINATION
 

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Stroked Z28
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Discussion Starter #17 (Edited)
:welcome: There is some really good information there. Thanks for sharing.

I had somebody run Virtual Engine Dyno Pro for me based on:
My Crower Hot Street Beast cam (same profile as first post)
4.030" bore, 3.750" storke, 5.700" rods
1.6 rockers
Dart 64 cc heads w/ 200cc runners
10.3:1 CR
Edelbrock RPM intake
Q-Jet carb
18* initial w/ 36* total

And... drum roll please... on paper this thing produced:
461 ft*lbs @ 3750 RPM & 434 HP @ 5500 RPM
With a 2" spacer (won't clear the hood, but what the heck):
467 ft*lbs @ 3750 & 451 HP @ 5500 RPM

He had the LSA off a little on the cam, but I can drop 50 hp & still hit my target. At this point, I'm more worried about my tire budget than anything else :thumbup:

EDIT: No, he actually had the LSA & lobe center correct. The numbers stand.
 

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Save a horse, Ride a Cowboy.
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I think that I would prefer the most power for the dollar spent.

There is enough difference in the price of the heads to far offset the cam change, etc. But, hey, it is only 44 hp more than your computer simulation, and I do recall, it IS your money to spend.
 
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