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67 327 with dart heads

  
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67 327 with dart heads

 
JOE327 JOE327
New User | Posts: 1 | Joined: 12/12
Posted: 12/09/12
01:01 AM

When I was younger and less wise I built a 327 for a project vehicle.  Bored .060" flat top pistons , factory forged crank cut .010"/.010" balanced.  I used a 280 magnum comp cam and Harland sharp roller rockers.  Performer RPM intake manifold with a 650 edelbrock carb.  Here is my issue.  I bought 200cc dart iron eagle angle plug heads.  I am running a TH350 with a 2500 stall but only have 3.08 gears.  It is terrible under 3500 rpm.  Other than getting different heads what can I do?  This is a street/strip vehicle.  I have a tci streetfighter 700r4 I am installing soon as well.  Thanks for any input.  

redneckjoe69 redneckjoe69
Addict | Posts: 2337 | Joined: 03/10
Posted: 12/09/12
05:19 AM

id wait and see how the 700r4 acts.    

  more rear gear or less cam will restore bottom-end power.

   welcome to CHP!  

68scott385 68scott385
Guru | Posts: 1990 | Joined: 10/09
Posted: 12/10/12
03:30 PM

+1 Joe

The 700s 3.06 first gear will help alot. Make damn sure you get the throttle valve cable adjusted right. If it's wrong, the trans will be junk in 5 miles or less. Bowtie Overdrives has an article explaining the hows and whys of it.  
68scott385 68scott385 68scott385

68scott385 68scott385
Guru | Posts: 1990 | Joined: 10/09
Posted: 12/10/12
03:31 PM

http://www.bowtieoverdrives.com/index.shtml  
68scott385 68scott385 68scott385

76Skylark 76Skylark
Guru | Posts: 853 | Joined: 12/11
Posted: 12/10/12
05:34 PM

The 200cc head is really just too big for a 327 street engine so put some gear in it and get the R's up and the engine will run like it is built to do.you have to get the air moving through the head to make use of them,If you are going to wait on the 700r4 put a 3.90 gear in it and Rev it up,  the 700 with the 3.08  will bog till 80mph in O/D. because of the O/D you can run even more Gear but the 3.06 first of the 700 will make first gear almost useless with more than a 4.10, that is why I like the 200r4. I used a 355 gear with the 200r4 but that was because that old Buick didn't want to turn past 5800 in O/D but you'd be holdin your breath and Smilin'.  

Dave632 Dave632
Addict | Posts: 2222 | Joined: 07/08
Posted: 12/10/12
05:45 PM

This is something all of us have done or probably will do if you race long enough.
We always tend to think bigger is better. I have put too big a carb, heads, cam on my engines before and all it does is hurt performance not help it. I remember Warren Johnson saying he has done that too so we are not alone.
A milder cam might help especially if you are street driving it. Smaller heads would also be a plus. I remember one small block 350 I had with a tunnel ram. It would be pretty dead until it hit 3500, then it was like a nitrous shot. I ran that just on the track so it was not a big deal there. I started out with a mild converter which would only stall at about 2500 so it was dead at the start even with 4.56 gears and a th350 3 speed.  
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pepsi1 pepsi1
Guru | Posts: 1718 | Joined: 09/11
Posted: 12/10/12
09:32 PM

A 2500 stall convertor and 3:70-3:90 rear gears maybe more gear. Depending on how tall your tires are. That will give you a much better punch and get you into the cam a little earlier. When you get that all set-up go a step colder in the heat range of the plug. Cool

Bob  

skyeking skyeking
Addict | Posts: 2738 | Joined: 08/09
Posted: 12/13/12
05:12 PM

Hi there,
With Small standard tyres I would go for the 3.7 Rear gear..  
skyeking

BuzzLOL BuzzLOL
Enthusiast | Posts: 380 | Joined: 12/10
Posted: 01/01/13
11:16 PM

.. Domed pistons would help the low RPM power some... that 230/230 duration at .050" lift cam really needs about 11:1 - 12:1 compression ratio to work right... in the 1960's, GM put 11:1 stock with smaller 222/222 & 224/224 cams... would also make your 200cc heads work much better...

.. Torque converters are usually rated for a 'small block' (350") or 'big block' (450") engine... if your converter is rated for a 350" engine and 2500 stall, it's prolly only getting up to 2000-2300 RPMs somewheres with a big cammed, low compression 327 engine... a better fit would be a 3500 rated converter which you could prolly get to stall up around 3,000 RPMs or better... especially with more compression ratio...

.. That 230/230 cam wants to really make about 450-475 HP, so those 200cc heads could actually work pretty well on your 339" engine with more compression ratio and the proper stall converter...

.. In this dyno chart, red is torque curves, blue is HP curves, all engines have 1960's stock heads, top lines are 11:1 350" 224/224 cam, middle lines are 11:1 327" 222/222 cam, bottom lines are 9:1 350" same 224/224 cam:

Chevy Small Block Hydraulic Testing Dyno Comparison  

pepsi1 pepsi1
Guru | Posts: 1718 | Joined: 09/11
Posted: 01/02/13
12:12 AM

Dave's got you covered on this one. Less duration is really needed to day. Why read a little of what I wrote below. Lift isn't to much of a problem until you run into valvetrain clearance problems.

  The Cam Makers today are using what they call under the curve. In short it means they are able to find more area under the base circle so in turn you need less duration to do the job as a Cam with 10* more duration.
  The lifters follow the cam better, we can even run less lift in some builts and get the same results. Don't forget the Cam is spinning twice the speed of the Crankshaft. So its doing a lot of work. Well thats my 2 cents.

  I believe by the end of this decade, the words hydraulic or mechanical flat tappet will be pasa. They won't be in a gear heads vocabulary. I am an older gear head I am pushing the use of Roller Cams. YES they are MORE EXPENSIVE but in the long run will be well worth the sacrafice. Roller Cams do things so much better. GM has been using Hydraulic Roller Cams since the early 1980s. Mechanical roller cams have been around since the late 1950s. Grin  Cool

  Just a little FYI. Crane Cams has been quoted as having 80,000 cams in stock.

Bob  

BuzzLOL BuzzLOL
Enthusiast | Posts: 380 | Joined: 12/10
Posted: 01/02/13
12:45 AM

.. Pepsi meant to say the cam runs at half the RPMs of the crankshaft...

.. Not sure what Crane has since the bankruptcy... or where their cams are made...

.. End of this decade is only 7 years, don't expect things to change too much by then for us... maybe manufacturers mostly electric vehicles by then... or maybe not since they're still not really practical... and hydraulic fracking is bringing down the cost of crude oil/gasoline produced here in the midwest USA...  

tuffnuff tuffnuff
Moderator | Posts: 7827 | Joined: 12/09
Posted: 01/02/13
11:21 AM

+1 Buzz.,. cams run at 1/2 crank speed.

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

Pontiacman2 Pontiacman2
Moderator | Posts: 8956 | Joined: 09/08
Posted: 01/02/13
11:41 AM

+2  
Pontiacman2
Pontiacman2

Professional Hi-performance engine builder