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Discussion Starter #1 (Edited)
Ok, here's a new head porting project thread to follow.

Artie (aka AGPD45) is a Steve's Nova Site member and a mechanical engineering student in Rolla, Mo.
He has a 383 in a 1st gen Camaro he recently acquired. It runs "ok" but he knows it could be better so he want's to make some improvements. We are going to try for over 500 hp with a hydraulic roller cam and these heads. He has a Scat cast crank and I beam rods with TRW forged pistons. His current cam is a Comp XE284H. He doesn't have any 1/4 mile times for a baseline.
After some discussion and negotiations I agreed to help him out. He sent me the heads to assess. The heads show it was running very rich with a thick layer of carbon in the ports and on the valves.
Here's Pix of one of the heads after a night in the parts washer:
 

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Discussion Starter #2
On disassembly, I discovered the keepers had hammered the groove edge into a burr. If you look at the picture you might be able to see the edge is mushroomed, if that's the word.
I had to file the burr off every valve to get the valves down the guides without tearing up the guides. This is a potential problem that could lead to dropping valves. I'll have to investigate why this happened.
 

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Discussion Starter #3
Here's the port template used for Kev's ported S/R head. His heads flowed 247 cfm when finished, I think. Notice the Sportmans move the pushrod pinch and the port roof is taller.
I'm going to do a baseline on the flow bench and then get to work making chips. We'll see what we get when I'm done.
 

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keepers

On disassembly, I discovered the keepers had hammered the groove edge into a burr. If you look at the picture you might be able to see the edge is mushroomed, if that's the word.
I had to file the burr off every valve to get the valves down the guides without tearing up the guides. This is a potential problem that could lead to dropping valves. I'll have to investigate why this happened.
Does that mean that the keepers weren't installed properly? And also, could this have affected the previous performance of the motor?
 

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I had to file the burr off every valve to get the valves down the guides without tearing up the guides. This is a potential problem that could lead to dropping valves. I'll have to investigate why this happened.
Paul: What causes this to happen? I have a set of L98 heads (used) with LT4 hot cam springs / retainers, and I had the same problem. Seems like the keeper corners created raised edges on the valve stem. Stems will not come out of the guide until the edges are filed down.
 

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Does that mean that the keepers weren't installed properly? And also, could this have affected the previous performance of the motor?
Assuming none of the parts were mismatched, I'd guess valve float could cause the damage to the valves. How many miles were on the motor? How high would you rev it?

That guide boss in the intake ports is huge. It will be enlightening to see how much flow is improved by reshaping it.
 

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Discussion Starter #7 (Edited)
Today, I hauled the pass side head to Kinetics Racing engines and did the baseline testing. Even though I cleaned it, it still stinks like shellac. I had to put it in the bed of the truck it was so bad. Must have been running stale gas or something.

I don't have a definitive answer on the keeper groove damage yet but I will check it out further. One speculation is the XE "Extreme" cams are harder on the valvetrain due to quicker opening and closure rates. The intake valves are steel and the exhaust are stainless. The keepers and retainers are black oxide steel. I'm thinking the retainer and keepers just don't fit the generic valves very well, but I don't have a final judgement yet.

Anyway, here's some pixs of testing. Graphs of data in next post.
 

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Discussion Starter #8
Intake "Before" graph

Here's the Intake Graph with the Stock S/R (similar flow as a "camel hump") for reference. One thing I noticed was the kink at .525" lift. If you only took data at .100" increments as magazines often do, this anomaly would not show up. The other surprise is Kev's ported S/R's flow better (247 cfm) than these stock Sportsmans (236 cfm).
That won't be the case when I get done with these. I know they won't be as good as Dave's AFR's but there will be an marked improvement.
 

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Discussion Starter #9
exhaust "before graph

Here's the exhaust graph.
 

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Whoot whoot, my S/R's are pretty good! If I could just find a forged 406 rotating assembly and a roller cam we'd really be in business.

Kev

I think finding a forged 406 rotating assembly is not the problem. It's paying for it. Besides your just spinning the tires now. More power won't help with that. Just work on your chassis, traction and reducing weight and you'll be in the 12's. Whatever you do, don't hurt those heads! ~Paul W.
 

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A young guy on the Chevelle site put this combo together in 2004.

"Brian’s Stroker "Street" Small Block

350 +.040" 4 bolt block 3.75” Stroke crank= 385ci
-SRP Forged Pistons #138094 with Plasma Moly file fit rings
-9.8:1 CR
-350 block .004" deck
-Clevite 77 bearings
-Fel-Pro Gaskets
-Eagle Cask Crank 3.75" Stroke External balance
-Crower Sportsman 6” cap screw Rods ARP main studs
-Milodon louvered Windage tray
-GM Stock oil pan and pickup
-Melling Standard oil pump
-Cloyes true Roller timing set
-World Products Sportsman II 200cc intake port heads 72cc combustion chambers fitted with Race Flo 2.02/1.60 back-cut valves bowl blend
-Performer RPM intake manifold
-Holley 750 with Proform Main Body
73 front jets, with a 5.5" powervalve.
83 rear jets, no rear powervalve.
-4 hole spacer 1/2” tall
-Holley carb Heat Shield
-Crower Cams #00321 (Ground on a 108LSA) Solid Flat tappet 242/248 Dur .050” .482/.504" valve lift Crane double Valve Springs #99893-16
-Rocker Arms- Crower Stainless Steel 1.5
-Comp One Piece .080” wall 5/16” Pushrods
-MSD Ready-to-run Pro Billet Blaster II chrome coil
-Headers- 1-5/8” primary 3” collector, 33” average primary tube length
Merge style collector
-3” head pipe/H style crossover Dynomax Oval UltraFlo mufflers, 3” dumps.
-Carter 172gph mechanical pump plumbed to 3/8" fuel line.
-Mobil 1 5W-30 oil, Ford F-type transmission fluid Coastal 75w-90 Gear oil
-Autolite AR-13 spark plugs
-TH-350 by STR, ATI 10” Treemaster Converter, 4.10 gears Cheetah shifter
-Summit Steel OEM style damper
-Koni Street Adjustable front shocks set full soft
-Moog 6314 springs
16.44” …………………….free height
.601”………………………..wire dia.
289 lbs/in………………..rate
1744………………………..total load"

First serious run netted a 11.60 ET with a 1.61 60ft in a 3260lb 67’ Camaro"

At the end of the 2006 season and with lots of suspension tuning and a Pro Systems Carb, he ran 11.15 @ 117 mph with this combo.
 

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Discussion Starter #12 (Edited)
Here's all the stock iron head intake flow data I have so far. These are actual tested numbers not magazine or vendor numbers.
The Vortec does best out of all of them at lifts under .460" which coincidently is the max lift on stock Vortec's.
Notice the 182's do much better at mid lift than the S/R's. Kev procured his S/R's from Ebay and they may have been factory rejects being resold (Bill Mitchell sells the rejects). I don't know that for a fact but the casting was real rough. Much rougher than ones I've bought direct. Certainly the flow is less than they advertise.

Next up is to make some measurements and then start grinding. Stay tuned!
 

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Paul, I beat a set of stainless 2.08 valves up in a set of AFR 210 that looked very similar. Because that motor was never reved very high, I couldn't believe it was valve float. My machinist tore the heads apart and concluded it was valve bounce after looking at the seats and valve faces. I would guess it's still something associated with too light of a spring for the ramp and valve weight. In my case, the springs were pretty soft on the seat pressure. But because we had decent open pressure for a hydraulic cam, I thought everything was well. Just something to consider in your investigation.
 

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I can see this thread is destined for the "best of tech" section. Paul thanks for your time and documentation on this project.

By the way... that sure does look like my HP calculator in one of those pics;)

Tg

(This is my second one. The first one got stolen by a meth head who didn't know how to work it and threw it away but sold my laptop for a whopping $20. They don't make the HP48 anymore and the Ebay prices are climbing. That meth head could have gotten $200 for the calculator! ~ Paul W.)
 

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I think finding a forged 406 rotating assembly is not the problem. It's paying for it. Besides your just spinning the tires now. More power won't help with that. Just work on your chassis, traction and reducing weight and you'll be in the 12's. Whatever you do, don't hurt those heads! ~Paul W.
I've got aluminum body mounts, SSM lift bars and hopefully some DR's coming. I'm thinking fiberglass bumpers are next b/c there's a ton of weight in the 4th gen's bumpers.

Kev
 

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I've got aluminum body mounts, SSM lift bars and hopefully some DR's coming. I'm thinking fiberglass bumpers are next b/c there's a ton of weight in the 4th gen's bumpers.

Kev
Keep most of the rear bumper weight. I think the benefit of having the weight there behind the rear tires will out-weigh the ET gains from the weight reduction. You need to get that front end "loose". Trick springs and drag shocks should be on order!

This is just my $.02!
 

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heads

Wow, this thread is really turning out well... i'm pumped already to see some results... In the mean time, learning a little about head tuning is well worth the wait. Thanks for all the insight, Paul.

Artie
 

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Discussion Starter #18
We've got to get you ready for the PRP showdown. Now that DriveWFO isn't going to have the Badass AFR's he's going to be toast!
 

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I bet those Canfields will do just fine;) I'm gonna still need a bigger hammer and better chassis to run with Dave and Tom this year.

Kev
 

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Please keep us posted on the valve lock issue. I've never seen anyone give a definitive answer on why this sometimes happens.
 
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