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Chevy 383 Vortec Engine - Noisy Lifters

 
deemann
V-6 Camaros rule!
Posts: 61
Joined: 02/09
Posted: 10/30/13 01:39 PM

Chevy 383 stroker  motor, with GM iron VORTEC heads.   The block is a 350 with 1-piece seal, that receives this machining:  Bored and honed- Deck gasket surface- Grind for rod clearance with stroker crank.  The VORTEC iron heads, feature 175cc intake ports - heart shaped 64cc chambers, for greater strength and performance.                                    
The engine comes with a NEW 5qt. oil pan and balancer installed, along with a NEW (Satin or Polished finish) dual plane intake manifold.  The engine will be painted the color of your choice, and comes with valve covers of choice (Chrome plated steel - Black/red letters - Gray/blue letters- Polished aluminum).

The crankshaft is by "EAGLE" products, with 5.7" long I-beam rods and  SpeedPro  pistons with moly rings, giving pump gas friendly (10to1) compression ratio.   A Comp Cams hydraulic camshaft, spec's (231` duration at .050" with .480" lift) with matching valve springs, providing TREMENDOUS acceleration, with a power range of 2000-5700 rpm's.

HE ALSO INSTALLED AN ACCEL HEI DISTRIBUTOR, PLUGS AND WIRES ALONG WITH AN EDELBROCK AVS THUNDER 800 CFM CARB.

THIS ENGINE WAS BUILT BY HERB GLASSMAN.  I DID ALLOW HIM TO SLIGHTLY PORT AND CLEAN UP THE HEADS.  IN A 1976 CAMARO WITH A TURBO 350 AND 3.73 GEARS, THE LIFTERS ARE EXTREMELY NOISY WHEN YOU GIVE IT A HARD ACCELERATION.  I HAVE USED BOTH 92 OCTANE NON-E GAS AND 93 OCTANE 10% ETHANOL GAS.  THE TIMING AND TUNING WERE DONE USING A CHASIS DYNO.  THE ENGINE BUILDER SAYS THIS NOISE IS NOT THE LIFTERS, BUT PRE-DETONATION.  EVEN BACKING OFF THE TIMING SEVERAL DEGREES - WE STILL GET THE NOISE.  THE DYNO SHOP THINKS IT MAY POSSIBLY BE THAT THE PUSH RODS ARE A LITTLE TOO SHORT, BUT CERTAINLY A PROFESSIONAL ENGINE BUILDER THAT HAS BUILT HUNDREDS OF THESE EXACT ENGINES WOULD HAVE GOTTEN THE GEOMETRY RIGHT?    

NOW SINCE IT WAS ON A CHASIS DYNO, HERE ARE THE RESULTS:

278 HP AT 5,400
307 TQ AT 5,400
THEY BELIEVE WITH THIS CAR AND PARTICULAR TRANSMISSION, A REGULAR ENGINE DYNO WOULD HAVE PUT IT AT 340HP AND 375TQ.  THE BUILDER ADVERTISES IT 455HP AND 450TQ.

ANY SUGGESTIONS ON THE NOISY LIFTERS OR WHAT THAT COULD BE????  

Post Reply
skyeking
I mow my lawn and find Chevys
Posts: 2738
Joined: 08/09
Posted: 10/30/13 03:59 PM

Hi there,
Process of elimination..Bear with me.
What is the total timing? For that cam I would
want 12/34* for a start.
If the push rods are too short I would think
that it would show up at idle and then the
hydraulic lifters would  and can compensate
over 40/1000" and then quieten down the noise.
 What is the static compression?.
 Dyno HP figures are sometimes a salesman's ideal!!!
   You do NOT need an 800cfm for that combo.!
 A 700 DP Holley will do enough up to 6600..
 That cam will have gone to lunch by then no matter
 what else you throw at it.
 I would be pleased to get 410 bhp @ 6200rpm.
 The Torque is a potential of 425 according to the
 exhaust system within the 1st 36" from the exhaust VALVE!!.
  You have a very good combo in general.
  You will persevere until it is right otherwise you would
  not be here..
  All the very best..Skyeking.  
skyeking

Post Reply
deemann
V-6 Camaros rule!
Posts: 61
Joined: 02/09
Posted: 10/30/13 07:27 PM

Hi Syeking:

The static compression is 10.0:1

I'm not sure of the total timing, but I'll find out.  


All in all, I'm am very satisfied with this engine and the $ spent.  I just have to get these noisy lifters fixed.  It's just a shame to hear this noise even over a great sounding engine and exhaust (it has the long tube headers with a 2.5" dual exhaust, exiting just before the back axle, with Flowmaster Super 40s and a "H" pipe connector.  This combo does move a 4,000 car well and if the 340HP/370TQ is a true estimate; I'm satisfied.  The 800 cfm was something he threw in because he was out of the 750 that he normally uses.  The 800 is jetted down quite a bit and out of the 3 adjustments to give it the fuel shot; it's on the leanest one.

I had a 383 stroker with all the best parts that was right on the borderline of being streetable at 460hp/475tq, but ultimately I can can 3 of the above vortec combos for what the 460/475 cost me.

All in all, I just want a good weekend and evening cruiser without having a 3,500 stall converter, but still being able to smoke the tires and have great performance with quick acceleration.  

If there are any other small and inexpensive things I can do on this combo to get a little more power, acceleration and quick response - let me know.  Thanks.  

Post Reply
Dave632
I mow my lawn and find Chevys
Posts: 2253
Joined: 07/08
Posted: 10/30/13 07:53 PM

I have never heard of an engine detonating at idle or unloaded. Is that when the noise is heard?
 Higher stall converters will eat up a lot of HP. Normal is in the 20% range but with say a 5000 stall it will be more like 30% and the more power put to it the more loss there is. Example a 700 hp BB made only 496 on a chassis dyno with a 5000 stall converter. I remember picking up 9 mph in the 1/8th with a converter change alone. The motor was just blowing right thru the other one.
I had the same experience when I put the 68 Camaro on the chassis dyno. I put some extra juice, N20, on the motor and when I hit the throttle it immediately went to the rev limit.  
[[SUPPORT AMERICAN CARS, STOMP A RICE CAR TODAY.]]

Post Reply
skyeking
I mow my lawn and find Chevys
Posts: 2738
Joined: 08/09
Posted: 10/31/13 05:05 PM

Laugh   Hi there,
 Let us talk HP @ the crankshaft.
 I know that an engine with your buildup
 with a 234*/244* + 490/1000" up and down
 will generally give 410 HP at 5800 with a 750DP.
  This I have seen and is not a theory.
 Your "Stally" need only be 3000.
  Detuning an oversize carby seems to be a lost cause
 if you want a real good result.
 Only way is trial and error with other carbs.
 750 quady/Holley/ or 725 Barry Grant which I have used
 and would recommend. [Most Holley bits are interchangeable.]
  Your Cam is too small for 460 hp. Heads would need to be 190s++
 Is your trans strong enough for 400hp strong usage?
   Reliability is what counts and the more power you demand
 moves you away bit by bit from that objective. Shocked
    Finally I suggest that you clean up the carby situation.
  Check the push rod length..If there is no help from the builder
 then do it yourself or get a 2nd opinion..Be polite but firm.
   That's my 2cents worth Bud...Over and out...Noel in Australia.
  There is no guarantee that the Boss actually assembled your
  motor and once the lid is on they all look the same. Cool  
skyeking

Post Reply
Dave632
I mow my lawn and find Chevys
Posts: 2253
Joined: 07/08
Posted: 11/01/13 03:33 PM

Yes Noel, I sure agree with having the proper drive train to support big power.
I tore up every bit of the drive train at one time or another due to big power and not enough drive train strength to handle it. My Camaro made 860hp at the rear wheels with juice and by the time I had assembled that combo I had the experience to put enough strength in the drive train to handle that much power. Unfortunately I could not get that much to the ground in that car or the more powerful Beretta, with 17" slicks, before it.  
[[SUPPORT AMERICAN CARS, STOMP A RICE CAR TODAY.]]

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