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Are there any potential performance issues linked to blocking off egr passages on the intake?? I know the legalities, just want to know if it can damage anything. All other emission equipment has either been removed or plugged. Can I fabricate my own plate to go above the gasket with the old valve housing? Thank you for any replies.:)
yes you can, and of course it is illegal to modify emmisions equipment on a car!!! I assume you are doing this for off road use only, right?????
as long as your in a state with no emmisions laws beyond a certine year, here in Ny it's 1996 or newer, and catalitic converter present 1975 up, other than that nothing else. easiest way to remove it is get a intake that does not have an EGR port. personally, I wouldn't go through the hassle, for the small amount of HP you will gain, it won't be worth the hassle.
I'll say yes. The only things that are original in this s10 is the VIN and the interior. We live by the seat of our pants here in Tennessee. Thanks Dave;)
Sorry Matt,
Was replying to Dave while you were posting.
A little bit goes a long way for the dime. Just want to make sure there would not be the potential for engine damage. I am not that familer with specific head design, although I have heard of "egr heads"??? This is a GM crate from '93. All I know is 64cc and center valve cover bolts:confused: Any hints on determining if these heads are "egr"? Do I even need to know with this mod?
Matt, any horsepower gains that are that cheap are worth doing..... Most horsepower gains cost big $$$$, I don't ever turn down the cheap or free gains!!!! If you can do 10 little things that gain you 2 horsepower each and cost you little or nothing, you just made the same horsepower increase you would get from a $250.00 intake manifold purchase.....
Dave is right on the money here. For instance, eliminating the EGR and PCV might allow you to run another 20-40 psi cranking pressure without detonating on pump gas. Don't hold me to these numbers, I'm just trying to make a point. If you can make 160 psi on pump gas with the crud on the motor without detonation, taking it off might allow you to run 200 psi for instance without detonating.Quote:
Originally Posted by Dave Severson
Grandpa always said the PCV was the only decent thing the engineers ever did ( regarding emissions ) so don't disconnect the PCV. On the other hand, the EGR is shit. All it does is reduce performance ( yes, to reduce the carbon monoxide ) You don't even need to remove it. Just remove the vacuum line.
With all due respect to you and your grandfather, if I were building a max effort motor, it would not have EGR or PCV on it if I didn't have to pass any sort of emissions test in my area.Quote:
Originally Posted by firebird77clone
Woah woah woah. I have a pcv valve on the motor I built for my car and a breather on the other valve cover. Removing the PCV gives more horsepower? How come I was never told this?!
Quick: tell me what I need to make more horses. I have an edelbrock 600cfm with the pcv line running to it and the valve covers have the rubber grommets on the edelbrock valve covers. Would I have to plug the hole on the carburator as well? I don't want to have to get rid of my edelbrock valve covers unless I absolutely have to. I still have my old 283 '66 Valve covers that don't have holes punched in them from the factory.
But tell me. If I did remove the pcv.. would I get better or worse gas milage?
Installed the plate today and ended up with a rough idle. The plate is above the gasket and is sealed up good. Seems to be a rat-a-tat-tat at the plate.
Do I need to readjust the idle mixture? Up the idle RPM? Rough at 650 and smooths out at @800.
To correct myself in the initial post, I do have the PCV at the valve cover to the front of carb. I did'nt know that was an emissions piece.
14 degrees BTDC initial advance with timed vac.advance. The full time vac. and the rear vac. port of the carb are plugged off. Edelbrock 1406. Super unleaded 93.
o. kthx :)
Here are the specs:Quote:
Originally Posted by DennyW
Engine Part Number: 12355345
Displacement: 350 Cubic Inches (5.7L)
Horsepower: 300 @ 5000 RPM
Torque: 369 Ft. Lbs. @ 3500 RPM
Maximum Recommended RPM: 5500 RPM
Compression Ratio: 9.1:1
Block: P/N 10105123 Cast Iron with straight four-bolt bearing caps, late model 1-piece rear main seal design.
Bore and Stroke: 4.00” x 3.48”
Crankshaft: P/N 14088527 Nodular cast iron, 1-piece rear main seal design.
Piston Material: P/N 12361371 Cast Aluminum
Connecting Rods: P/N 10108688, 1053 Forged Steel
Cylinder Heads: P/N 10159592 Bare Head, Cast Iron 64cc Chambers [Old P/N 12356026]
Valvetrain: Overhead Valve with Pushrod
Camshaft: Hydraulic Flat Tappet Design
Intake Valve Dia.: P/N 10093027 1.94”
Exhaust Valve Dia.: P/N 14088641 1.50”
Advertised Lift (Int/Ext): .435/460
Rocker Arm / Ratio: P/N 10089648 / 1.50 Ratio
Valve Lash: Zero
Engine Idle Speed: 650 RPM
Spark Plugs: R44TS
Spark Plug Gap: .035
Oil Pressure (Normal): 40 PSI @ 2000 RPM
GM aluminum 4bbl intake
Edelbrock 1406 (600CFM) electric choke
Headman swap/conversion headers
Flowmasters (40 series)
No cats.
THM 350.
Denny,
I used 1/8 plate steel and used the old housing. I dont know if the gaskets have the heat provisions. I do have a 1 inch spacer plate under the carb.
Denny, with all due respect to you, when you're on the gas, off the gas, on the gas as in Gymkana, trials, road racing, etc, etc, everytime you're off the gas, you are sucking burned exhaust gases from the crankcase right into the intake manifold to dilute the fresh charge that comes available when you are on the gas again.Quote:
Originally Posted by DennyW
I repeat, for a max effort motor where it does not have to meet any emissions standards, I will vent the motor at the valve covers and run the hoses down to the back of the motor to atmosphere and run without EGR.
So, with the vac. gauge, adjust the mixtures until max vac.? I dont have anything other than the stock pointer on engine for timing. It goes to about 14 degrees. I usually run the highest timing just before detonation.Quote:
Originally Posted by DennyW
I have tried in the past to set timing with vac. gauge, but could not eliminate detonation at max vacuum.
Yep, I have had problems in the past with heat at idle. Had to get larger rad and more cfm fan. Maybe the full time advance will help that.
Thanks Denny
This is not a race vehicle by any means. Just trying to free up a little power, and clean up the engine bay. Pluged egr valves just aint pretty. I would like to keep the PCV to help keep the valve covers clean. I tried without once and just one trip down the road I was cleaning oil off the breathers and oil fill hole. Anyhow, Denny I got your point about setting idle mix with a gauge. The procedure is where I need help. Do I adjust the screws to achieve max vacuum? Do I check the vacuum at the manifold or the carb? Do this before or after setting the timing?:confused:
Techinspector,
I have no doubt in your experience and knowledge. Just a fun little s10 strickly for the street. Thanks for your suggestion.:)
What you can do, (I run practically the same setup you have, 355 sbc and an edelbrock 1406) is go to your local parts house and ask for a simple vacuum gauge, nothing fancy nothing too expensive. Should come with a rubber line that fits the small vacuum lines on the very front of the carb.
Get the engine warm and set your timing to what you need it to be (I run 12* BTDC)
The right vacuum port is the one you want to hook it up to since its going to be constant vacuum. The left vacuum port is for your vacuum advance used on the distributor.
Now with the car running and the guage hooked up to the carb, take a flat head screw driver and turn one of the idle screws in front all the way down to where it closes or when the RPM's drop at a noticeable rate, then back the screw out until the vacuum goes all the way up then starts to go down, dial that vacuum in to the max.
Do the same for the other adjusting screw.
And be sure to have a Tach hooked up to the distributor and set your idle to what your motor or camshaft manufacturer tells you to set it to. I have mine set within 650 and 700 rpms since mine is a 268/268, stock lift cam. Nice and choppy. :)
Now take that hoss out for a drive and see how she responds from a dead start! She should act great now!
Edit: Just combine what I said with Denny, he's got more know-how than I do! I've only got 3 years experience with this whole hotrod/carburator thing :P
Soon after blocking off the egr a rattle/knock noise developed. From the top it sounds like its comming from right under the intake close to the distributor shaft. From underneath it sounds like its radiating all the way down to the oil pan.:eek:
This noise is only heard when at idle, in drive or park. Has gotten progressively worse the last couple of days.
The engine doesnt get as warm as it should either, only about 145 cruising,160 running hard, but that may be a separate issue.
So I went hunting for the problem today. Removed the intake to check for obstructions, nothin'. Checked the dizzy gear, nothin'.
Since I am not that familier with how the intake and heads work together I got a question that may sound dumb, but here goes.
Am I seeing a single exhaust port on the intake side of each head?????
These smaller ports have a build up of what I would think would be carbon????
How do these work with the intake?? Could someone explain this? Do I have a problem with this buildup of carbon? Could that be causing the noise?
Mortec.com notes that these heads are 1987-up 64cc chamber 72'center bolt angle cast iron.
5.7LT GM crate-1993.
Blocking off an EGR valve won't cause an engine knock. Two unrelated issues. Maybe pull the plug wires one at a time, see if the knock quits on a certain cylinder. Depending on what type of knock it is, could be anything from detonation to a loose wrist pin or a broken piston. EGR is Exhaust Gas Recriculation and is designed to pump some of the exhaust gasses back through the engine to finish burning the gasses not burned the first time through the combustion process. IMO non of the smogger heads belong on a performance type engine. Lots of good heads on the market that don't have the emissions garbage built into them......
What is it specifically that classifies a particular head as emissions compliant or "smog" heads?Quote:
Originally Posted by Dave Severson
Might as well figure that any cylinder head made for passenger cars and trucks after 1974 is a smogger head. If you want good heads for performance forget the stock stuff and get the aftermarket aluminum or cast iron heads. The last few years the factories have finally put some performance back into their engines, the small V-8's are fairly good the way they're made. Now add a blower and upgrade the electronics and it's easy to get in the 400+ horsepower range with nothing but bolt ons and plug ins....
Picked up a set of Mr. Gasket ultra-seal intake gaskets today. I noticed that the gaskets are solid where the smaller center ports are located. Only have the bolts holes there. Will these work?:confused:
The packaging states for 1987-1995 Gen I SBC.
Application heads:
14101083...1987-up...350..........Gen.I, also used on crate motors, 285 or 300 hp, 64cc chambers, 72' center manifold bolt angles. (Mortec.com)