Hey guys,

I was playin around with my dyno software. And this is my new plan. I get some stable numbers, and a gigantic increase all the way around if I do this. However, I'm not sure of the stock Intake/Exhaust valve's size. THi is what I am going to do:

Replace my performer RPM Dual Plane (NEW IN BOX) intake manifold with a:
Edlebrock Tourqer II Single Plane intake manifold.

Take my stock heads to a speed shop and have them ported, and polished with this:

Intake Valve: 2.800IN
Exhaust Valve: 1.730IN

Like I said, the software is showing stable numbers, witha  peak range of:
570HP and 493 LB FT of tourqe at 6500RPM, that intake goes up to 6500RPM, and shows a growth of 4,000 - 6,500 RPM of HP/TRQ. With an operating range of 2,500 - 6,500RPM

I'm justin sayin, I looked it over, and you knwo I got some tiem left before the car is done, and I'm workin so hard on it, and spending all my time on it, why not give it some more power? The tranny was beefed up to handle 800HP I believe, I'll have to ask the builder... it could have only been liek 500HP... I don;t remember there was some confusion... I paid like $630 so I think the rating was high. the driveshatf, u-joints, and rear end are all stock. However I was once told that system could handle like 1,000HP, and 1,500LB ft of torque. IDK, its old... but jsut as heavy as a damn tree.

 

So I guess my final questions are:

What does everyone think?
And what are the stock intake/exhaust valve sized for stock 350 Heads in 1977?

Thanks guys,
-Louis

new77guy38677.1352546296

  Your stock heads are 1.94/1.50 valves. Bump it up to 2.02/1.60 would give you  nice increase in power, but 2.80? That's for big blocks! Remember, you'll be driving this beast on the street. And who's buying the gas? You should have plenty of power as you are now. Learn to drive IT first. The combo you are running now is more than enough to have loads of fun with. Big horsepower bragging rights are cool, no doubt, but if its not streetable you will be kicking yourself  and hating the car.

        Also, if the heads are ported too large, you defeat your purpose as well. We have all been following your build up as you have been good enough to ask questions here. Maybe just go to the 2.02's, but for now I think I would follow your builders advice. You can always change things later. The adage "Knowledge is Power"  isn't true. "Applied Knowledge is Power" is where its at !!!

                                                              Reid  '72 T-top

Well Reid,

Thanks for the info. I called some local machine shops and asked them about a valve job for 2.02/1.6 like you siad. And a port and polish job. Aparently for cast iron every shop here wants to charge me $550 for all this. Well, for $489 off summit I can get nice Edlebrock ALUMINUM heads with 2.02/1.600 ... so why would I spend $550 on my extremly heavy cast iron heads?

On that note, I asked 2 guys (as being machinists and all) on the intake. They said that the numbers I was producing witht aht torquer 2 was pretty awsome on the medium - high range. One guy said he but a single lan manifold on his 350  that was in a truck, and it was really sluggish ont he low end. Then another guy (an older gentleman) says he does it all the time, and has no problem. He suggested that if I was really worried about it, go witht he AIRGAP intake. So, what does everyone think?

Here is the engine sim dyno with 2.02/1.600 and a single plane manifold W/ a 600CFM flow, and a Comp Cams 268H camshaft



Here is the motor now:
1.94/1.500 cast iron, dual plane manifold, 600CFM flow, comp cams 268H camshaft


This is with the 2.02/1.600 heads and a dual plane manifold, with 600CFM flow and a comp cams 268H camshaft



I guess what I'm really worried about is having an engien that I paid almost 7K for is only going to produce a peak of
345HP/329lb ft at 5500RPM after the 20% in drivetrain loss. I'm trying new ways to really get this 350CI up there. I don;t wnat to ahve to put the engine in, and then like 3 months later take it out to put new heads on.  Not to mention those aluminum heads would take off quite a bit of weight as opposed to cast iron.

-Lou

new77guy38677.4843865741

  Louis- You are right about the weight savings  of the Edelbrock heads. v The Edelbrock is a great part. The Air Gap manifold may give you hood clearance problems though.....Is the price on the heads at Summit for the pair or each? 

       Remember...Speed costs....How fast do you want to go? Another thought....How are your brakes?

                                                   Reid '72 T-top

Hey Reid,

I don't really wnat to go go fast persay. I would never speed, or pull nothin crazy on the street. If I were to get caught, my parents would for sure give me a severe whippin, and prob sell my car over a speeding ticket. And if I were to (god forbid) but wreck the Vette, my life would end, I would be missing a part of me again. I'm just a firm believer in you get what you pay for. And 7K for a peake of 345/329 at 5500 is kinda  rip off at 7K. And with the weight of the engine, well... some aluminum heads would do niclely. As for the brakes: they are new upgraded 2 piston o-ring calipers. The rotors have a lot of meat on em, and I'm going with ceramic brake pads. stopping power is decent, but not a crazy 6 piston wilwood setup. Would that single plane tourqer 2 manifold slug me down at a standard cruising 1,500RPM? What about the low low end, liek 500RPM, and 900RPM what about a 1,000RPM?

And the heads are sold individually.

Thanks Reid,
-Louis

new77guy38677.515787037

A couple of things.  The valves you first suggested won't fit in a small block head.  The later numbers work well.

Next, if you have not driven a 345 Hp car, you will be surpised how really fast and strong that is.  IT'S VERY IMPRESSIVE on the street.

My car is now up to 206 hp and 254 ft lbs at the wheels. Accounting for my transmission and gear ratio, it's a guess of about 270 at the flywheel.  (my tranny alone uses 42 HP, about the worst out there in those terms) When I took my Dad for a ride his impression was, "I wonder what kind of G's that was?"

Don't get me wrong, in terms of HP, more is almost always better.  But don't go so far as to lose the bottom end, or driveability on the street.  500 + HP on the street is fun for a short time, but can be annoying or difficult to drive on a semi regular basis, or on a cruise.  Also keep in mind the fuel you will need to use with different combinations.  Of course if that's the goal, go for it.

Cylinder head make a HUGE difference in the way the car will perform. So a good set of heads can really make you happy.  And the alum heads allow for lower octane fuel.  This could mean 92 octane pump gas instead of special racing fuel in some cases.  Something to consider.

As has been said before  "How fast do you want to go?  How much do you want to spend?"

  Right you are Ken! Louis, the 1.94 heads will do you just fine. I'm trying to figure out how you've spent 7G's on a rebuild though. For that price you could have bought TWO  ZZ4's with the same hp rating. Look, get you freaking motor in the car and get on the road and enjoy! When I was your age I only dreamed of having a Corvette. Now I have nightmares over it! (j/k)

         You will definitely have the kick in the pants feel with your present combo which is very streetable and should be very reliable as well.

                                            Reid  '72 T-top

Hey Reid, and Ken,

 

Thanks for your help and all. Its going to end up costing me more money upgrading the engine now, than I have. I'm just going to go ahead and load in the current engine now. And then, upgrade it later. The total cost of what I have now is: $5,029.87. It will porb be around $5,500 when I get everything.

If you want HP and torque stroke the motor to get more, like Ken said those valves won't fit and if you hog out the ports and go with a single plane there goes all the bottom end, If I wore size 20 shoes I would have alot to brag about but it would become a pita after a while, its not the meat but the motion, you can only get so much out of a 350, if you want power and drivability stroke the motor, you want it to breath do some light porting around the bowel area and some port matching, run a middle of the road solid lifter flat tappit cam and kit with roller rocker, unless you are running alot of compression lets say 11-12 to 1 you have no need for alum. heads, cast iron will work fine and make more power for a 9-10 to 1 motor, when you build a motor you want it to live, quaility parts cost money, hopefully alot of that $5700.went for good parts that will allow the motor to perform and stay together.

I have tried a single plan intake manifold on the street and for the speeds you run on the street if you dont want to get caught speeding do not get into the rpm range that you have to get into to make it work. The engine will have a very sluggish bottom end and will not come alive until you get above the cruising range. The two plane manifold will do just what you want your engine to do. The aluminum heads sound great, and your motor looks good. Get it in the car and enjoy it, you might be suprised at the power you already have.