ninobrn99

iTrader: (8)

Hmm...how should I start?? Ok..lets start fromt he beginning...I went from a stock ls1 to a cam only in jan of 04 or 05..i can remember anymore.. Got it tuned and everything and the car ran great! Kept the stock pulley, maf and injectors btw. I drove the car from TX to CA and it ran great! Took the car to the track in feb and made 3 passes...Thats when it started going down hill. I could tell right away that the car felt different... it just didnt feel right. Well after getting it scanned I saw my trims were way lean 25+. I didnt find any leaks or anything so after a while I decided to pull the intake...go figure, when did the intake swap, I didnt put the gaskets in yeah i know..stupid! Ok, so I fix it and get the gaskets in, get a mild retune from a friend because at the time I knew nothing about tuning. Ltrims arent as bad, but mpgs are really bad now! Cam at the time was a 228/228 114. I was getting about 12-13mpgs mixed...It wasnt the driving style because it happens when both my wife and I drive it. Well later on I decided to put the stock cam back in and when I went to start her up, i had multiple misfires and a loud knocking sound. after getting the car home and saving, I got a new cam (f13 112) a set of ls2/ls6 heads, and a set of 42# injectors. I also got hptuners. Get the car put back together and it starts right up. Still having the same issues though as far as mpgs, but now a bit more oil is being burnt and coolant is being lost. I checked the head gaskets and they werent leaking..didnt see anything from the radiator or waterpump either. The issues that I cant seem to figure are: my mpgs being so shitty, 11-12mpgs now, burning about a qt. of oil every few hundered miles, losing coolant and from idle to 3500 the car is a dog, but it still managed to put down the numbers in my sig. I mean it has no pull even after the new rearend and 3.90's. Ive also noticed quite a bit of knock, but havent been able to figure out if its false or not. Im currently running the ls6 timing tables to be safe. I had a leakdown test performed friday and here are the results.
Cyl 1 17%
Cyl 2 15%
Cyl 3 22%
Cyl 4 22%
Cyl 5 20%
Cyl 6 27%
Cyl 7 30%
Cyl 8 28%

Before you ask, yes the injectors are tuned correctly. I was certain the I was going to need a new shortblock and I still may, but before I go and shed out the money that I really dont have, I need as much input as I can get from everyone.

ninobrn99

iTrader: (8)

could it be that the block is cracked? Its the only other thing i can think of. Im thinking of just replacing it and see if that was it, but thats one big investment!

ShevrolayZ28

iTrader: (4)

hmmm...no leaks? Are you finding any coolant in the oil pan? Or maybe it's being burned along with the oil. Could it be that oil is leaking past the rocker arm bolts and into the combustion chamber? Did you seal the threads?

Also, if those leakdown numbers were done with the engine warm, I think you've got some issues there. Even cold, they are pretty far apart from each other.

How many miles on this motor?

ninobrn99

iTrader: (8)

motor was warm. it has close to 49k. I havent changed the oil yet..ill be getting that done this week to see. I also have not pulled the valve covers to check. I have my wife taking the car to someone I know so they can look at things. Im thinking i should get the bottom end and see if that fixes the issues. I did not seal the threads to the rocker bolts...never needed to.

ShevrolayZ28

iTrader: (4)

You really should be trying to seal those threads.

https://ls1tech.com/forums/showthrea...ghlight=sealer

I'm surprised at the leakdown results for a low mileage car. Before you buy a short block, was there any attempt at determining if the leakage was out the heads and not past the pistons?

In the meantime you could pull the dipstick and see if the oil has coolant in it.

Disclaimer: I'm no expert, I'm just throwing out a few ideas.

Good luck.

ninobrn99

iTrader: (8)

leakage as in the coolant or the oil? the coolant isnt coming from the head gaskets. ive checked that over and over..well before i left for deployment i did. the coolant is running low over time, so its a small leak and it must be burning up fast because there are never any puddles under the car.

SmokingWS6

iTrader: (1)

If you can't find a leak, sounds like there could be a crack in the block/sleeve. A member of our local car club is going through the same situation, has to add coolant every other week or so, and change oil often. Fuel trims are fine though

svo 42's sound too large for a basic 346 h/c swap.

ninobrn99

iTrader: (8)

Thanks. I already ordered a new shortblock from HPE. However, I dont think the 42's are too much for a 346. They're a good cusion and if I didnt get them, Id have something smaller and then wouldnt have enough for the extra cubes ive got coming

1936FordPU

iTrader: (3)

did you get the air pockets out of the cooling syste?

It may be leaking behind the water pump just not enough to leave a visual on the ground. Instead just running down the front of the motor and gooing up.

ninobrn99

iTrader: (8)

sure did. bleed once i got it running and again a few days later just to be safe.