Cascade Crew

redlava · Posted: Mon Apr 02, 2007 6:53 pm Post subject: Engine Build Questions

I plan on going with a new engine set up this summer and I have some basic questions. The car is for mainly street with a trip once in a while to the strip. Right now I have a 2000 rpm stall in my car. I do not really want to change the stall at this point. The cam I am looking at is a voodoo with an rpm range of 1800-6200. Is this rpm range to high? Should I step it down to this range of 1400-5800? I should I get the cam with the slightly higher lift on the exhaust side because it would help the head flow better on the weaker flowing exhaust side correct?

My second question is about the heads. I plan on going with the 200cc iron eagle platinum heads with the 64cc chambers. Would the 200cc intake runners be good for a 350 that could possibly be a 383 some day? I understand that you can’t have more that a 10 to 1 comp. ratio on iron heads. Right now my heads are chevy casting 462624 with a 76cc chamber I can run 87 octane just fine. Should I be able to just bolt on these 64cc chambered heads if I am willing to run 92 octane. Would I be able to just reuse the stock head bolts or should I get some after market ones?

With this combo should I go with a bigger carb like a rebuilt non-cc quadra-jet or should I stay with my 600cfm edelbrock carb?

Sorry for the long post and thanks for the help.

chevymad · Posted: Mon Apr 02, 2007 8:18 pm Post subject:

200cc heads should work. Both Paul and Rodney are running 200s. Can you post the exact cam info? Or at least the part #s?

redlava · Posted: Mon Apr 02, 2007 8:24 pm Post subject:

These are both hydraulic flat tappet cams part numbers were pulled off of jegs web site

638-60102LK

Advertised Duration : 262°/268°
Duration @ .050 IN/EX : 219°/227°
Gross Valve lift IN/EX .468''/.489''
LSA and ICL 112/108
RPM Range: 1400-5800

638-60103LK

Advertised Duration : 268° /276°
Duration @ .050 IN/EX : 227° /233°
Gross Valve lift IN/EX .489''/.504''
LSA and ICL 110/106
RPM Range: 1800-6200

chevymad · Posted: Mon Apr 02, 2007 8:33 pm Post subject:

Do they give a recommended stall. I'm thinking the first cam is going to be your best bet. The 2nd is a nice cam but probably wont work with your auto. The tighter LSA will make it idle rougher as well. Head bolts are fine with the iron heads. I'd say the 600 is going to be on the small side. The edlebrock's are nice for being easy and running well, but you're leaving some hp on the table using one. The q-jet can be a nice performer but most don't know how to set one up right.. especially with a cam. This leaves you with holley or demon.

Are you running a 700r4? I had a devil of a time setting up the correct tv linkage on my holley. The holley brackets do NOT work correctly. Ended up having to buy a $120 kit from bowtie overdrives to get things working. Also you'd need to rig up a lockup setup as well.

Schultzy89GTA · Posted: Mon Apr 02, 2007 9:03 pm Post subject:

60102LK
SBC Voodoo Hydraulic Flat Tappet Camshaft and Lifters
Hydraulic; Mid–level performance street cam with excellent drivability. Exceptional replacement for "muscle car type cams" with automatic transmissions. Works well with stock type exhaust manifolds and dual plane intake with mild 4 bbl carb. This is an Awesome 4X4 and performance marine cam where "Dry" exhaust is used. Improved valve springs and roller rockers recommended."

60103LK
SBC Voodoo Hydraulic Flat Tappet Camshaft and Lifters
Hydraulic; The most awesome "268" cam ever produced! Out–powers all others! This High Performance street cam likes 2400 RPM stall, 700 cfm carb, dual plane intake and headers. Makes un–equaled power to 6200 RPM with proper valve springs. If you're looking for a Very Strong cam with great street manners for your "Crate Motor" this is it Factory EFI motors need custom chips/tuning.

redlava · Posted: Mon Apr 02, 2007 9:09 pm Post subject:

I will go with the lower 60102LK. So the stock head bolts will work fine with iron heads? Do you think the compression ratio will be over 10:1 with the 64 cc chambers

Nathan J · Posted: Mon Apr 02, 2007 9:43 pm Post subject:

the heads are kinda big but would work, maybe you should look into some vortech heads little less money and will give some good low end tq and some nice hp still they have a 170cc intake runner, 64cc chambers. the 200cc runner head is good for a built 350 for a 383. with what you want to do you would have to spin some rpm to make use of those 200's. but if you plan to step up later go ahead. also get new arp head bolts. dont go spend all the money on new heads and use old bolts.

Twilightoptics · Posted: Mon Apr 02, 2007 10:10 pm Post subject:

Run some numbers in a dynamic compression ratio calculator.

That's where compression ratio really comes in.

Get a big enough cam and you can run 11:1 or 12:1 with iron heads.

Go with the first cam. It's going to be a much nicer beast to tune and run. In comparission, I'm running 200cc intake heads like Brandon mentioned, and my cam is considerably larger than either of those.

I'm with Nathan. Buy some new bolts. I had a bolt snap off in the head once. Cost me some anger, time, price of a headgasket, and new bolts anyways.

Now as for your 383 upgrade someday.... it depends. Those 200cc heads will be on the large aggressive side for the 350, but might be kinda small for the 383. You could do the vortec's since they are cheaper, you'll need a manifold... and run bigger heads when you do the 383 someday. All depends on what you want to do. Same with the cam. With a 383 trying to put out alot of power, either of those cams will be too small.

No one can know your compression ratio without the following:

-Exact Bore (4" or is it re-ringed? Over bored?)
-Stroke (assuming 350 so 3.4 Cool

-Head CC (64CC)
-Head Gasket Thickness (Compressed thickness in inches)
-Head Gasket Bore (Bore of the cylinder opening of the gasket)
-Piston to Deck Clearance (Deck Height. How far down from the top of the block the piston sits)
-Piston CC (Are they flat, dished, domed? What cc is the dome, or the dish/valve relief)

On my motor:
-Cyl: 8
Bore: 4.032
Stroke: 3.48
CC: 66
Head Gasket: .015
Head Gasket Bore: 4.1
Deck Height: .025
Flat Pisons: 8.65

Quench: .04
CU IN: 355.47
Liters: 5.825
Static Compression: 9.75
Dynamic Compression: 8.108
For example.

http://members.uia.net/pkelley2/DynamicCR.html
Has a compresison ratio calculator, aswell as you can input your cam specs and find out the dynamic compression.

Dynamic Compression:
"Why it matters: A 355 engine with a 9:1 static CR using a 252 cam (110 LSA, 106 ICL) has an intake closing point of 52º ABDC and produces a running CR (DCR) of 7.93. The same 9:1 355 engine with a 292 cam (having an intake closing point of 72º ABDC) has a DCR of 6.87, over a full ratio lower. It appears that most gas engines make the best power with a DCR between 7.5 and 8.5 on 91 or better octane. The larger cam's DCR falls outside this range. It would have markedly less torque at lower RPM primarily due to low cylinder pressures, and a substantial amount of reversion back into the intake track. Higher RPM power would be down also since the engine would not be able to fully utilize the extra A/F mixture provided by the ramming effect of the late intake closing. To bring the 292 cam's DCR up to the 7.5 to 8.5:1 desirable for a street engine, the static CR needs to be raised to around 10:1 to 11.25:1. "

Twilightoptics · Posted: Mon Apr 02, 2007 10:15 pm Post subject:

PS. A quench of .04 is perfectly ideal.

"Note: The quench distance (piston/head clearance) should always be set between .035" and .045" with the lower limit giving the best performance and detonation resistance. "

This is the deck height + gasket thickness.

Run a felpro replacement gasket like in most of the mags on a stock deck 350 (in most cases) will yeild .041(gasket)+.025(deck height)=.066

That will yeild a motor that is easily prone to detonation.

izcain · Posted: Mon Apr 02, 2007 10:21 pm Post subject:

good info there paul.

Really you need to access what you want to do with engine. For something that is mainly running on the street dont go for the max HP try to build a well rounded package that produces a nice flat torque curve down low cause thats where you will use it the most in everyday driving. I woulds also recommend running some various engine combos on a desktop dyno simulator..... They can acually be very helpful as a learning tool when it comes to cams and such.

Quasi-Traction · Posted: Mon Apr 02, 2007 11:45 pm Post subject:

*takes notes*

This is all handy information.....I'm bookmarking this! Don't know it as in depth as Paul, Zac or Dewey, but I'm learning more all the time!

Sounds to me like we kind of plan on building similar motors, Redlava!
I'd likely be doing the 170cc Vortec's, and the 60102 Lunati cam, Vortec RPM air gap and a Holley 6010, with the Auto, and I'd opt for a 650 or 700cfm Holley DP with a Manual.

For the bottom end, here's what I"m thinking:
Speedpro Flattop Hyper's, 5.7" rods, a .010 or .012 deck on the block, using a standard 350 crank, and a .03 or .04 overbore.

Mostly I'm just looking Just looking for something I can safely spin to 6000rpm consistantly, using Hydraulic lifters that will net about 300hp at the flywheel.

Twilightoptics · Posted: Tue Apr 03, 2007 12:06 am Post subject:

izcain · Posted: Tue Apr 03, 2007 7:08 am Post subject:

For a more street able engine you should also try to go with a little more LSA since slightly more will give you that flatter power band. A tighter LSA tends to make for a peaky engine. Which is fine with high stall converter and deep gear so that you can get the engine in it's power band quickly. Most people tend to over cam the car and end up with poor results.

redlava · Posted: Tue Apr 03, 2007 10:22 am Post subject:

crane cam 270-113512
Idle Quality: Good
Operating Range: 1600-5400 RPM
Duration Advertised: 262° Intake / 268° Exhaust
Duration @ .050'' Lift: 212° Intake / 218° Exhaust
Valve Lift: .446'' Intake / .459'' Exhaust
Lobe Separation Angle: 114°

comp cams 249-12-242-2
Operating Range: 1600-5800 RPM
Duration Advertised: 268° Intake / 280° Exhaust
Duration @ .050'' Lift: 224° Intake / 230° Exhaust
Valve Lift w/1.5 Rockers: .477'' Intake / .480'' Exhaust
Lobe Separation Angle: 110°

The crane cam would give me a good idle and flatter power band correct? The comp cam would give me a rougher idle, peakier power band and more power over all?

This is a 750 cfm holley vacuum secondary carb 510-O-3310CK would this be better than a edelbrock?

I do not know what type of pistons are in the motor at the moment though I have seen them. They have slight indent in them for the part of the valve to go into. The motor has been bored over but I do not know by how much. I figured if I had two equations i could figure out if it would work or not by solving for CR and the empty space that is unknown in the cyclinder. I just needed to figure out the max possible compression on 87 octane to find the CR.

Quasi-Traction · Posted: Tue Apr 03, 2007 2:02 pm Post subject:

Twilightoptics · Posted: Tue Apr 03, 2007 4:35 pm Post subject:

izcain · Posted: Tue Apr 03, 2007 4:36 pm Post subject:

Are you planning on just having an N/A motor then?

Meaning nitrous in the future? Or boost?

Nitrous likes a little wider LSA as well.

The peaker engine makes things funner I think as long as you have the gearing to compensate for the loss of low speed.

NHRA427 · Posted: Tue Apr 03, 2007 4:43 pm Post subject:

Very nice write up twilghtopics, about the quench. We always deck our higher compression blocks to zero. Not a lot of people deal with quench. They just throw the engine together.

Quasi-Traction · Posted: Tue Apr 03, 2007 8:51 pm Post subject: