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1G 4G64 block/4G63 head

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Anthony Boni

5+ Year Contributor
213
23
May 13, 2018
Wrightstown, New_Jersey
Alright guys I need help!!

I have a G4CS block with a 4G63 head. I’m using a 4g64 timing belt, stock 4g63 cam gears, and OEM 4g63 timing components. Currently I have the intake and exhaust cams retarded half a tooth as I’ve seen on other write ups. Car idles and drives fine. I set my base timing to 5° BTDC. I’m running into an issue for when I get into boost. I get knock at only 13 pounds/4K RPM. A lot of knock. Like 5 degrees retarded. I was told by a very reputable source that using stock cam gears retarded is NOT correct. So I went ahead and ordered some AEM True time adjustable gears. My first question; could cam timing being a few degrees off be what is causing my knock?

Follow up question: I also have an FP1 intake and an fp2 exhaust cam. What I’m trying to figure out is, do I line up the adjustable cam gears like normal, retard 3.5* on both the intake and exhaust because of the extra 6mm deck height, then time the cams according to their cam cards from that new baseline?

I could REALLY use some input on this because I’m seriously getting drained. This car was terrible when I first bought it. I’ve done too much to be stumped now. Thanks..
 
If that 4g64 block has a stock bottom end then that the reason its knocking, it has too much compression to be used in a turbo application, 8-9 lbs is all that you can safely run with that, unless you install turbo pistons in it. A few degrees here or there on your cams is not causing that, you can try running some race fuel or E85 to confirm that its compression limited.
 
If that 4g64 block has a stock bottom end then that the reason its knocking, it has too much compression to be used in a turbo application, 8-9 lbs is all that you can safely run with that, unless you install turbo pistons in it. A few degrees here or there on your cams is not causing that, you can try running some race fuel or E85 to confirm that its compression limited.
It’s not stock, it’s a built motor. I was running 21 pounds all day no problem until I fixed my base timing. It was like 1-2°ATDC. Now it’s right on 5 degrees BTDC and knocks a lot. I was going to pick up some c16 right now to see if that makes it go away.
 
Now you have +3 timing degrees on all the timing map
So that can cause more pressure at cylinders AND result on More heat AND prone to knock
Try rest 3 degrees on slidders AND check how it goes


I guess I’ll update this thread.

My #1 injector was flowing 16% less than the other three. I didn’t think it was my injectors because they were new from FIC. I sent them in to get check and I got an email back saying they would replace the injector and clean/flow test for free due to the faulty injector.

So it was leaning out, we threw fuel at it, still knocking due to lean fuel mixture on #1 cylinder. Wideband took an average of all 4 cylinders so I was reading rich, yet still detonating.

It had nothing to do with timing, both mechanical and ignition.
 
Since then, I’ve built a 2.3 stroker.

Thanks for the tips guys, but I was way off base with my assumption that it had to do with the mechanical timing.
 

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