NEED HELP WITH KNOCK UNDER BOOST

[86DarganGN]

I would contact iskey and ask what the recommended spring pressure is for that cam. Stock tb springs are just ok for the small stock cam. That cam may need a little more pressure to keep the valves from floating.

Here is my opinion :

I am sure he sold the cam to other TB customers and it would be interesting to hear his (Isky's) theory and real world results with so much overlap in a turbo application?

If "I" wanted a lopey cam . . Sure . . I would use it. Not saying the cam is the source of the KR but think about the air making it to the O2 sensor under low load . . . countered by the neg impact on mass flow at boost from BP and reversal.

Hope you find the issue(s) as it can be very frustrating.

Thanks so much for your expert advice, I will transfer it to Rod at Liskey.

 

[86DarganGN]

Since you haven't had a chance to rev it out at full boost (24+) you still don't know if the springs are strong enough. That will be determined.

Springs and/or chip have been my uneducated guess for some time now after eliminating so many related vacuum possibilities. What spring would you recommend?

 

[Jerryl]

That cam doesn't have a lot of overlap. It's -16 degrees at .050". Same as other small cams of similar lift. Theoretical lift may cause an interference problem on the stock ex guides of not machined


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Ok. I read +16 @0.050

Intake Close -8 BTDC @0.050
Is that not the same as 8 ATDC?

Exh close -8 ATDC @0.050

 

[Jerryl]

Thanks so much for your expert advice, I will transfer it to Rod at Liskey.

No no no . . . I am not. It was an opinion.
The expert is Bison, seriously.

 

[Mr.Spool]

Did you try a few gallons of race gas or lower the boost slightly to see if the knock went away?

 

[86DarganGN]

Did you try a few gallons of race gas or lower the boost slightly to see if the knock went away?

I tried a can Lucaus Octane Booster in fresh 93, engine loved the extra octane but I still had the same amount of knock at WOT. Plus it turned the spark plugs a red color and made them hard to read!

 

[86DarganGN]

Rings failed to seat??
OLD shop trik on fork lift engines: Hold it at 2K, shoot a "snort" of Bon Ami cleaning powder into the intake, using a ketchup squirt bottle. Bout 2 snorts, making the engine pull down, and the rings were as good as they were going to get.
Dyno break in...15 mins @ 10% load. Check for leaks, noises, etc, and it's hammer time. As "broken in" as it's going to get.

Boost req'd to "seat" the rings? Suppose this same engine is n/a. Then what?

Will a simple compression test verify if the rings sealed?

 

[Mr.Spool]

I tried a can Lucaus Octane Booster in fresh 93,

Im Talking about real race gas,unleaded or leaded is your choice but a little bottle of Lucas isn't going to do the job.

 

[V6sleeper]

Sounds more and more like a fuel issue, how much timing is in Reds 93 chip? is it 20 years old when 93 was actually 93?
Also I would try different injectors then the 42's, they aren't the greatest... flow matched 60's

 

[86DarganGN]

Sounds more and more like a fuel issue, how much timing is in Reds 93 chip? is it 20 years old when 93 was actually 93?
Also I would try different injectors then the 42's, they aren't the greatest... flow matched 60's

I purchased the chip, injectors and "bunch" of other bolt on parts from the late Jay Frick in 2012. I do not know any of the specifics about the chip design other than it is a 93 octane Red Armstrong Chip (F3599H), I called Red twice and did not get any useful information.....or customer service. I was taking Jay's advice with the intentions of having his assistance, if needed, his shop was sorta local or within a day travel distance.

 

[bison]

Ok. I read +16 @0.050

Intake Close -8 BTDC @0.050
Is that not the same as 8 ATDC?

Exh close -8 ATDC @0.050

Chances are that is a misprint. That would be over 30 degrees more overlap than typical with small lobes like that. Cam cards are generated based off of input numbers out of a catalog typically and don't represent the actual lobe 100%. I'll punch these in and what comes up.


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[bison]

Just looked at it again. Ex closing precedes in opening. Ex close @.050" is 8 btdc. In opening @ .050" is 8 atdc. Looks like -16 degrees at .050"


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[Jerryl]

Just looked at it again. Ex closing precedes in opening. Ex close @.050" is 8 btdc. In opening @ .050" is 8 atdc. Looks like -16 degrees at .050"


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I looked at it again myself . . And you Sir, are correct.
"I" on the other hand, stand corrected.

 

[86DarganGN]

I want thank everyone for their help and valuable opinions concerning my knock under boost problem. With several small constant tuning adjustments the knock has been reduced. Before the WOT adjustment was (4.28) the knock with 8-10 lbs of boost was 5.2 at 789mv. The WOT currently adjusted to 4.52, I am only seeing 1.9 -2.3 degrees of knock with 16-17 lbs of boost when the transmission shifts from 2nd -3rd gear, then it goes away until the transmission shifts to 4th gear (1st time under boost). In 4th gear 16 lbs of boost, I had a constant 3.0 degrees of knock at 761mv, recall mph values 095/078 (not sure I understand the mph values). All four test runs were from a rolling start for about a ¼ mile +/-. The TPS with the throttle plate in the idle position was .46 (key on position) and .48 (idling), the engine exhaust smells really rich (burns your eyes rich). The IAC is 20 and MAF 05. The MAF Translator is adjusted to #5 10% lean at idle but that adjustment did not seem to make a difference. The MAF Translator is adjusted to #4 WOT 8% rich?? Not sure about that adjustment, I think it helped reduce the knock at WOT but not 100% sure. My last adjustment set the TPS with the throttle plate in the idle position to .44 (key on position) and .46 (idling), WOT 4.50 but I have not tested that adjustment. I plan to test with Sunoco 260GT 100 octane gasoline and install a RJC power plate.