Too much boost :(
Thread Starter
Joined: Nov 2001
Posts: 3,066
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From: Sunny San Diego
Too much boost :( Heads
Finally got the heads installed. Changed the pulley from a 4.10 to a 3.70. Set the tranny to shift @ 6200 instead of 6800.
Went for a test run. Hit 10# of boost @6800.
Check the tune and adjusted it again for 6200.
2nd run, hit 8# of boost @ 6300. Then started to hear a little knock. I am guessing a rod.
Timing was still set @ 17* and no detonation.
I'll post a clip of the noise tomorrow.
Finally got the heads installed. Changed the pulley from a 4.10 to a 3.70. Set the tranny to shift @ 6200 instead of 6800.
Went for a test run. Hit 10# of boost @6800.
Check the tune and adjusted it again for 6200.
2nd run, hit 8# of boost @ 6300. Then started to hear a little knock. I am guessing a rod.
Timing was still set @ 17* and no detonation.
I'll post a clip of the noise tomorrow.
Last edited by Ed Blown Vert; May 7, 2005 at 11:22 AM.
Originally Posted by Ed Blown Vert
Finally got the heads installed. Changed the pulley from a 4.10 to a 3.70. Set the tranny to shift @ 6200 instead of 6800.
Went for a test run. Hit 10# of boost @6800.
Check the tune and adjusted it again for 6200.
2nd run, hit 8# of boost @ 6300. Then started to hear a little knock. I am guessing a rod.
Timing was still set @ 17* and no detonation.
I'll post a clip of the noise tomorrow.
Went for a test run. Hit 10# of boost @6800.
Check the tune and adjusted it again for 6200.
2nd run, hit 8# of boost @ 6300. Then started to hear a little knock. I am guessing a rod.
Timing was still set @ 17* and no detonation.
I'll post a clip of the noise tomorrow.
Were you runing a stock bottom end???? How many miles????
Hope it is not that bad, .
I wouldnt think youd have any problem running 10# on a stock bottom end as long as your tune was good. Where you running a WB at the time? Did you go lean?
Did the heads up your compression? What is it at?
Did the heads up your compression? What is it at?
Thread Starter
Joined: Nov 2001
Posts: 3,066
Likes: 0
From: Sunny San Diego
Heads were 71 cc, so CR should have been around 9.5. Alot better than the 11:1 I was running. I don't think I went lean. I scanned the whole run without any detonation.
Still on the stock bottom-end with 87k miles. I knew I was going to have to get a new forged bottom-end but was hoping to have it last a little while longer.
Knock
Still on the stock bottom-end with 87k miles. I knew I was going to have to get a new forged bottom-end but was hoping to have it last a little while longer.
Knock
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Man ED Im sorry to hear that. I took the long road and went ahead and got my bottom end forged. Taking a little longer than I wanted it to but I guess its worth it. SDPC gave me a great deal. Your looking at about 2200 + shipping using the stock crank.
Thread Starter
Joined: Nov 2001
Posts: 3,066
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From: Sunny San Diego
Does it sound like rod knock? Could it be the valvetrain?
$2200 isn't that bad. I was planning on $6K for an installed forged shortblock. But if I can get away with my crank all the better.
$2200 isn't that bad. I was planning on $6K for an installed forged shortblock. But if I can get away with my crank all the better.
Launching!
Joined: Nov 2002
Posts: 224
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From: Florida
It's higher pitched than what I'm use to, but I've never lost a rod in an aluminum block to judge it by.
I'd check the flexplate before you pull the motor.
If it's in the valvetrain you should notice a miss in the exhaust note.
I'd check the flexplate before you pull the motor.
If it's in the valvetrain you should notice a miss in the exhaust note.
Thread Starter
Joined: Nov 2001
Posts: 3,066
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From: Sunny San Diego
Flexplate? Check it for what??
I pulled the driver-side valve cover, everything seems to look ok. The sounds only seems to come from the front driver-side.
My guess is still the bottom-end.
I pulled the driver-side valve cover, everything seems to look ok. The sounds only seems to come from the front driver-side.
My guess is still the bottom-end.
Launching!
Joined: Nov 2002
Posts: 224
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From: Florida
Stock flexplates tend to crack between the bolts, and sound just like a rod knocking. That's why SFI plates are req'd for NHRA.
It's probably the bottom end, but I like to check the easy things first.
It's probably the bottom end, but I like to check the easy things first.
Thread Starter
Joined: Nov 2001
Posts: 3,066
Likes: 0
From: Sunny San Diego
Originally Posted by TA Dave
Stock flexplates tend to crack between the bolts, and sound just like a rod knocking. That's why SFI plates are req'd for NHRA.
It's probably the bottom end, but I like to check the easy things first.
It's probably the bottom end, but I like to check the easy things first.
Thread Starter
Joined: Nov 2001
Posts: 3,066
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From: Sunny San Diego
Originally Posted by strokedls1
Pull the valve covers and check the springs out. I have seen a bunch of springs break right off for whatever reason.
Thread Starter
Joined: Nov 2001
Posts: 3,066
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From: Sunny San Diego
OMG found the problem. Crank bolt back out and sheared the pins on the MMS pulley. Any idea where I can get another one? Or do you think I can just put bolts in and reuse it?
MMS Pulley
MMS Pulley