Hey guys, I just finished ordering everything I needed to complete my mild 350 street engine buildup. Here is what I have:

355 cubic inch/flat-top pistons
9.1:1 compression .040" quench, DCR 7.6:1 with a IVC of 59 deg.
SCE Pro Seal .015" head gaskets
Isky hydraulic cam 270/270, 221/221 @.050", .465/.465 lift 108LSA 2000-6200rpm range
World Products S/R Torquer 170cc iron heads, 76cc chambers, 2.02/1.60 valves, screw-in studs Flow 221/166 @.500"lift
Comp Magnum Roller Tip 1.52 rocker arms
Comp chromemoly hardened one piece pushrods
Holley 300-36 dual plane intake
600cfm Holley vac. sec carb
Transmission Specialties 2000-2400 stall
3.23 gears
84 z28 camaro (3500lbs?)

What do you guys think. My goal throughout this build is 375hp/400ft lbs at the crank, runs on 89 octane and have a solid 12sec street car on a budget. Do you guys think I am far off from this? I have heard the torquer heads benefit from bowl work especially around the intake valve guide area. What kind of flow/hp would I pick up from this? Any opinions/thoughts welcome. Thanks a lot.

I donno about power, but I do figure that it will be a dandy motor, imho!!

That said, I do think that you need to be up closer to 9.75 to almost 10 to 1 CR with that cam!!

Use 70 cc chamber heads to up her CR. to like 9.75 or so!! 67 cc heads should put you right at 10.05 or so CR.

pdq67

Pdq67, name?? I could have them milled to 72cc which would bring compression to 9.5:1 and DCR to 7.9:1. I am really looking to run this on 89 octane. Is that still reasonable aslong as I keep it cool and watch timing? 93 octane is getting rediculous here lately. Those world heads have thick decks so milling isn't an issue, aslong as it doesn't cost an arm and a leg to have that done. Im on a tight budget. What would be the downside to having the 9.1:1 compression with that cam. Still in the range of DCR according to pat kelleys DCR info. Will it be a little sluggish down low? I was thinking not with the 270 cam and the 170 runners. Id really appreciate everyones opinions on this. Thanks

Keep in mind that PDQ67 is from the days of manly compression and high octane fuel was cheap ;)
I like the buildup, and think it will all be a good match for a strong street performance engine, although I think your hp/tq estimation is a bit high. Your DCR will operate on 89 octane easily, but the old style combustion chambers are not nearly as detonation resistant as the newer heart shaped chambers, nor are they as conductive to making power (especially the 76cc size). If you don't have the heads yet, I would highly suggest a set of dart iron eagle 180's or something similar, and about another .5 compression. I run a 9.4-1 355 with vortec heads and a XE268 cam on 89 octane in a heavy truck with tall gears and a tight convertor, and tow with it a lot, and it has terrible quench (about .080"), yet it operates on 87 octane in a pinch with no detonation. A car generally won't see near the same kind of loads as my truck does, and I get by with a calculated DCR of either 7.78 or 7.88 (one or the other off the top of my head). I seriously doubt I could get the same results with an open chambered 76cc head.
With a 180cc performance head, out of the box, and about 9.5-1 compression plus the rest of your setup, I believe you will reach your goals.

I like the set up. It all looks like it will work well together, and that is the most important part of any build. That is a little milder version of my last 350 set up. I was running a bigger dual pattern Comp XE274 cam and, a Stealth intake but over all similar. Not great top end but a very good street motor with good torque.

Travis, i was looking before at flow numbers just to get a basic idea, those 170cc world castings actually flow just as much as the dart 180's. I bet if I cc'd the runners, they would spec out to more then 170cc. The heads are already ordered and on their way, but if I mill them down 4cc's to 72cc's that would put my compression up to about 9.5:1 and DCR 7.9:1. I am on a tight budget and I got a really good price on a bare set of the world 170cc through Bill Mitchell race engines. I bought all of the parts and will lap, assemble, cleanup, etc myself so i know they are done right.

I just got the august issue of CHP where they did the cylinder head testing. The dart S/S heads which spec'd out to 73cc chambers. The intake runners are advertised at 165cc but spec'd to 178. They flowed 225/185 @.500" I think the world castings are probably about the same. They put down some pretty impressive numbers on a 383 with a XE274H. 431hp/476ft.lbs. The numbers are probably inflated, so even if you knock 20-25hp off, they are still quite impressive for a 165(178)cc 73cc head. Even though mine is a 350, its showing that open chamber heads can make some decent power if matched up correctly.
After all that rambling, should I up compression to 9.5:1 by milling and what kind of difference are we talking about with about a half a point of compression change. Thanks everyone, you guys are great

You will be fine BUT a bit better if you can cheaply cut your heads to give you about 9.5 to 1 CR, imho..

If not, leave it alone.

But please read Travis real close b/c he play's a lot with motors like he mentioned to try to hit that "sweet-spot"! Right Travis?

pdq67

Bill Mitchell didn't send the heads out yet, so I cancelled the order just in time. I was having second thoughts about those world castings so I decided to get something better. Everything else I ordered is already on its way, now I just have to decide on another set of heads. What do you guys think, dart iron eagle 180cc or the S/S 165cc? Does anyone sell those iron eagle S/S that are cut for 2.02/1.60's, all the ones i've seen are 1.94.1.50. I can get the dart heads with the modern heartshaped combustion chamber in 72cc which would give me the 9.5:1 compression. What does everyone think? Will I be a lot better off with a set of heads like those darts and will I be able to reach the 375hp/400ftlbs easy?

There is quite a bit more to heads than just raw flow numbers. Combustion chamber shape plays a big part too, plus a modern style chamber will allow less timing to be needed for max power which further allows more compression on the same octane of fuel. I've got tons of articles written by David Vizard with direct back to back comparisons of gm 76cc heads vs. 64cc heads, with the same sized valves, same compression (by altering piston designs), and nearly identical flow numbers (actually the 76cc gm heads flow a touch better than the old double hump style heads). The 64cc heads absolutely destroy the 76cc heads in torque production, even with similar peak hp numbers.
I've also noticed in a lot of write ups and in the limited experience that I have with the S/R torquers is that without considerable porting, about 350hp is the upper limit for them. A 170cc intake runner volume is good for crisp street response though, along with a very strong midrange. Thats why I recommend a 180cc head with a modern chamber design.
For a 170cc head, I would much rather have a set of vortecs (not with your cam though), or better yet a set of 170cc edelbrock performer rpm heads with a 70cc chamber (the newer version with the modern chamber design). The S/R torquers and the S/S heads are not bad heads, I just think your goals are at a point where a better head design is needed

Have you considered Vortecs? They outflow the World heads and are about the same price. The downside is you will need a Vortec style intake, Vortec stytle rocker arms and Vortec valve covers. But if you have to buy that stuff anyways then it doesn't matter but a few $'s. Best of all, the Vortecs will bump your compression up to near 10:1 (fine with midgrade gas if you use the right cam).

If the Vortec parts are a problem then I would say the Iron Eagle 180 heads would be a good choise, better yet though IMO are the RHS 180cc Iron Lightning heads.

Hey guys, I just finished ordering everything I needed to complete my mild 350 street engine buildup. Here is what I have:

355 cubic inch/flat-top pistons
9.1:1 compression .040" quench, DCR 7.6:1 with a IVC of 59 deg.
SCE Pro Seal .015" head gaskets
Isky hydraulic cam 270/270, 221/221 @.050", .465/.465 lift 108LSA 2000-6200rpm range
World Products S/R Torquer 170cc iron heads, 76cc chambers, 2.02/1.60 valves, screw-in studs Flow 221/166 @.500"lift
Comp Magnum Roller Tip 1.52 rocker arms
Comp chromemoly hardened one piece pushrods
Holley 300-36 dual plane intake
600cfm Holley vac. sec carb
Transmission Specialties 2000-2400 stall
3.23 gears
84 z28 camaro (3500lbs?)

What do you guys think. My goal throughout this build is 375hp/400ft lbs at the crank, runs on 89 octane and have a solid 12sec street car on a budget. Do you guys think I am far off from this? I have heard the torquer heads benefit from bowl work especially around the intake valve guide area. What kind of flow/hp would I pick up from this? Any opinions/thoughts welcome. Thanks a lot.

EA3.2 thinks like this:

RPM···········1500····2000····2500····3000····3500 ····4000····4500····5000····5500····6000
Brake_Tq······265·····290·····309·····318·····322· ····321·····313·····290·····249·····203
Brake_HP······75.8····110·····147·····182·····214· ····245·····268·····276·····261·····231
Exh_Pres······.1······.3······.5······.8······1.1· ····1.5·····1.9·····2.2·····2.5·····2.6
Int_Vacuum····.2······.5······.6······.6······.6·· ····.6······.8······.9······1.0·····1.1
Vol_Eff_%·····66.1····70.3····74.9····78.7····81.7 ····84.1····85.2····84.4····81.1····77.3
Actual_CFM····110·····155·····207·····261·····316· ····372·····424·····467·····493·····513
Fuel_Flow·····40.1····56.8····75.6····95.4····116· ····136·····155·····171·····180·····187
A/F_Mix_Qal···99.5····100.0···100.0···100.0···100.0· ··100.0···100.0···100.0···100.0···100.0
BSFC··········.529····.514····.514····.525····.539 ····.556····.578····.618····.692····.810
BSAC··········6.630···6.454···6.446···6.582···6.76 2···6.969···7.250···7.758···8.675···10.157
Friction_HP···12······20······29······40······54·· ····70······89······114·····144·····181
Mach_#········.142····.190····.237····.285····.332 ····.380····.427····.475····.522····.570
Piston_Spd····870·····1160····1450····1740····2030 ····2320····2610····2900····3190····3480
Piston_Gs·····145·····258·····403·····581·····790· ····1032····1306····1613····1952····2323
Overlap_%VE···-5.4····-4.1····-3.3····-2.8····-2.6····-2.4····-2.2····-2.0····-1.8····-1.6
Int_AvgVel····85······113·····142·····170·····198· ····226·····255·····283·····311·····340
In_InertiaPrs·.0······.2······.6······1.1·····1.5· ····1.8·····1.9·····1.9·····1.8·····1.6
In_ResTunPrs··0.0·····0.0·····.0······.0······.0·· ····.0······0.0·····0.0·····0.0·····0.0
Ex_AvgVel·····114·····151·····189·····227·····265· ····303·····341·····379·····416·····454
ExTun_Prs·····2.6·····2.5·····2.4·····2.4·····2.6· ····2.7·····2.7·····2.5·····2.4·····2.3
Lifter_Pump_UpNone····None····None····None····None ····None····None····None····None····None
Spark_Adv·····21······27······28······29······30·· ····31······32······33······33······34

Well everyone, I ordered a set of bare Dart iron eagles, 180cc with a 72cc chamber (modern design) cut for 2.02/1.60 valves. Compression is now 9.5:1 with a DCR of 7.9:1. Now, what kind of numbers are we talking about? Thanks

RPM···········1500····2000····2500····3000····3500 ····4000····4500····5000····5500····6000
Brake_Tq······265·····289·····311·····321·····324· ····324·····317·····300·····262·····220
Brake_HP······75.6····110·····148·····183·····216· ····247·····272·····286·····274·····251
Exh_Pres······.1······.3······.5······.8······1.1· ····1.5·····1.9·····2.2·····2.5·····2.6
Int_Vacuum····.2······.5······.6······.6······.6·· ····.6······.7······.9······1.0·····1.1
Vol_Eff_%·····66.2····70.4····74.5····78.1····81.0 ····83.3····84.4····84.3····81.2····77.5
Actual_CFM····110·····156·····206·····259·····313· ····368·····420·····466·····494·····514
Fuel_Flow·····40.1····56.9····75.3····94.7····115· ····135·····154·····170·····180·····188
A/F_Mix_Qal···99.4····100.0···100.0···100.0···100.0· ··100.0···100.0···100.0···100.0···100.0
BSFC··········.531····.516····.508····.517····.531 ····.546····.565····.596····.658····.748
BSAC··········6.657···6.474···6.378···6.483···6.65 8···6.850···7.092···7.480···8.248···9.379
Friction_HP···12······19······29······40······53·· ····68······86······109·····137·····169
Mach_#········.147····.196····.245····.294····.343 ····.393····.442····.491····.540····.589
Piston_Spd····870·····1160····1450····1740····2030 ····2320····2610····2900····3190····3480
Piston_Gs·····145·····258·····403·····581·····790· ····1032····1306····1613····1952····2323
Overlap_%VE···-5.6····-4.3····-3.5····-2.9····-2.7····-2.5····-2.2····-2.0····-1.9····-1.7
Int_AvgVel····83······111·····138·····166·····194· ····221·····249·····276·····304·····332
In_InertiaPrs·.0······.1······.6······1.0·····1.3· ····1.6·····1.8·····1.8·····1.7·····1.5
In_ResTunPrs··0.0·····0.0·····.0······.0······.0·· ····.0······0.0·····0.0·····0.0·····0.0
Ex_AvgVel·····114·····151·····189·····227·····265· ····303·····341·····379·····416·····454
ExTun_Prs·····2.6·····2.5·····2.4·····2.4·····2.6· ····2.7·····2.7·····2.5·····2.4·····2.3
Lifter_Pump_UpNone····None····None····None····None ····None····None····None····None····None
Spark_Adv·····20······26······28······29······30·· ····31······32······33······33······34

This will only make 280hp? Something is not adding up. How do these crate engines make 350-375hp with mild parts? From your experience onovakind67, how accurate is that program? This is interesting... Thanks guys, you are great

EA3.2 is quite accurate. I don't assume that you are doing anything that you don't specifty, so if you didn't say it was in the engine, it's stock.
One thing that might add to your power is a properly designed exhaust system. A low windage oiling system would help, as would an electric fan and high efficiency water pump.

I ran it on a different sim http://www.virtualengine2000.com. There will always be differences, dyno to dyno, day to day - its not a exact science. I have ran engines on a true dyno test within a couple hours of each other and you will get differences.

The cell incoming air quality, oil temp, water temp, how long you are at full throttle/full load before pressing the start test button.... Even though the dyno tries to correct for this, it can still differ by up 8-10 (15 hp on high hp engines). Now when you consider running on a different dyno (possibly even different brand) in another part of the country at a different time of year, there will be even more differences. The final 'fudge' factor, is how long since the last dyno calibration. Were they 'friendly' on the calibration.

The most important is to find 'changes'. Did 'x' part help, or hurt. Is there more hp/tq or less. Thats where you want to concentrate.

I ran your latest combo with what I felt was typical of the enviroment of your car.

A 'typical' magazine article or advertisement probably would do the following:

Increase the porting quality (i am sure they spend a little extra time when they know the results will be published), without mufflers, ignition timing to the absolute max, cold air intake like a cell, electric fuel pump (we usually let the dyno supply the fuel so it can measure pressure and flow) and finally a electric water pump (these make mounting the engine to the stand quicker instead of worrying about belts and pulleys).

The difference would be significant. The most important is what your car does at the track, not that it matches xxx article.

http://www.hotrodink.com/Images/data/546/1Camaro763501.jpg

http://www.hotrodink.com/Images/data/546/1Camaro763502.jpg

Well, the company I ordered the set of Dart IE 180's from said they didn't have them anymore, the only thing available was the platinum for another $150.00. I told them for that price I'll just go buy a bare set of aluminum heads first. Anyway, I gave a call to Terry Rosebush Motorsports and they got me a set of Dart IE 200's for a heck of a price. So, they are a little bigger then I originally planned, but I have heard many good things about the Dart heads especially the 200's. The compression ratio is 9.5:1 now due to the 72cc chambers on the darts. Now I just have two more questions.

How are those heads going to be with that short duration cam?

Would I benefit from going to 1.6 rockers? Lift would then be 0.496"

Thanks for everyone's help.

Like I said earlier, you will be fine, imho...

I figure that it will STILL be a dandy STREET motor!!

Set it at 10.25 to 1 CR. and like travis say's I'm old-school, high compressioned and all, and hang on!!

pdq67

If you don't already have the rockers and you already have the cam then yes get the 1.6 rockers.