BigKID

iTrader: (5)

I finally got my home ported heads, cam, injectors and new radiator in sunday. Everything went good except for dropping the oil pump pickup tube bolt in the pan and not getting the pickup tube straight in the first time. Turned it over a few times and had two bad injector orings. After that it was time to fire her up. Cranked first try and actually ran pretty good even without having the new IFRs in for the 42#ers.
Now for the problem.... the truck runs fine in neutral. I hear no abnormal noise asside from the loud spring/valve noise. When I took her for a drive, I am getting instantanious knock retard up to 8* when I give it some gas. I can easily roll into the throttle and not get any but if I do it abruptly, it will instantly jump up to 8* and stay untill I completely let off the gas. It also sounds like something was hitting under the bottom of the truck but I put it on the rack yesterday and cant see anywhere the exhaust was touching or rubbing. I had false knock before so I did replace the knock sensors while I was in there with ones out of the donor motor I got the heads from.
Here is what I put in...
- Home ported 5.3 heads milled .040"
- Comp 918 blue strip springs
- FMS 214/216 .535/.545 113+4 cam
- RollMaster Single roller timing set
- FMS 7.350 pushrods
- 42# 8.1 Marine injectors

For tunning I just used my stock file with IFR scaled to new injectors and all my deletes (egr, O2s, etc). The l-trims are staying between -0.8 and -4.2. I only hit it wot once yesterday and I was only seeing 12* total timing with 8* kr. I have a full tank of 93 oct Cheveron gas in the truck as well.

Do you guys think this could be a bad case of false knock or is there something else I need to look into??

BenKey

iTrader: (1)

The only way I know of to rule out false knock is to run some high octane fuel to see if it stays or not.

goshawk23

i really can't help ya but i hope you get it straightened out without any damages.

greentahoe

iTrader: (2)

What does your compression come out to?? I agree with the high octane test.

BigKID

iTrader: (5)

I calculated my compression out to be about 10.25:1.
The only place around here to get 104 is at the track and I already have a full tank of 93. I guess I could find that thread with the formula to add methanol or ethanol (cant remember which) as an octane booster. I am also thinking of takeing my stock timing table and taking about 4* out of it to see if that remedies anything.

Black Blown 02

When I first did my exhaust system, It would hit when I got into it real quick. The engine torquing on its mounts made a pipe hit the trans crossmember. It set off the knock sensors.

I had to get under the truck and have my dad power brake a little to see where it was hitting.

BenKey

iTrader: (1)

Sounds like the higher CR has caused your KR. Were your timing tables still on the old setup?

Black Blown 02

Xylene is what alot of people use. If you have an almost full tank(~20 gal) and add 3 gallons of xylene it will bring you to around 96 octane.

BADMOFO

Will that burn out your 02sensors and Catalytic Converters? (if you still have them on)

BigKID

iTrader: (5)

Before the h/c I was running a 01 timing table w/ 4* added across the board. The first tune I put on after the h/c was with my stock virgin 00 timeing table. Then I added a stock 01 table (much smoother curves with a few degress less timing) with no change. By watching Atap, I am getting down into the single digits on timeing at part throttle while accelerating with no reduction in KR. I will try to get some logs up tonight for yall to see.