Blown head gasket?

BigEd · 12-08-2002, 08:43 PM

Crap!!.
I think I blew a head gasket. I went to check the oil and it had the dreaded foamy look to it. I'm running 10 pounds of boost and was a little lazy about getting rid of my 3000-4000 pinging I usually get in the winter time. Car is running fine. I'll do a compression check tommorrow. This will be a good excuse to port the heads while I have them off.
Eddie

Coupe50h · 12-08-2002, 09:16 PM

yea my friends 347 blew one and we really didnt notice until e.t. slowed, then we knew something was wrong, and checked the dreaded milky oil, yea while its apart take a die grinder to the heads and start cutting.

302man · 12-09-2002, 04:53 PM

Port the heads and find out why it happened and fix it ! If this has been happening for sometime, when its cold, and you only blew a gasket, you are lucky. There are cheap ways around pinging if you need help.

BigEd · 12-12-2002, 06:10 PM

Yea, I'm trying to decide on porting my heads, or getting power heads or going all the way with some 165 AFR's. On a budget you know. I've got the Speedbrain and I did knock the timing back to get rid of the ping but it must have been too late.
Thanks for the input.
Eddie

BigEd · 12-12-2002, 09:02 PM

302man,
I did end up backing off the timing but it was too late I guess.
I think the colder more dense air leaned me ought because the injectors are already maxxed out under boost in hot or cold weather. My fuel pressure already goes over 100psi under boost. I just need bigger injectors. For now I have lowered the timing to 26degrees in that region of pinging(detonation?)

Man I just noticed your times. That is fast!

sn95gt19 · 12-12-2002, 09:23 PM

sounds to me like you were running really lean, if your injectors were at 100% hopefully its just your head gasket, if it is your dam* lucky. good luck

302man · 12-13-2002, 11:13 AM

Big ed, I would most definetly look into injectors. 26 degrees is on the high side of pump gas for timing. Are you running any kind of boost retard ?

BigEd · 12-13-2002, 04:44 PM

302Man,
Here is my Spark curve for 100% load WOT.

Advance 26 26 26 26 29 30 27 25
RPM 2500 3000 3500 4000 4500 5000 5500 6000

In the Speedbrain.
this is total advance including the 10 Degrees static.
I taper back down over 5000 because boost is building so I am retarding timing when boost is building.

Is this way too much for supercharging?

What would you go with for timing in the range I have listed?
My boost starts at a couple of PSI at 3000 RPM and builds in a slow curve rising rapidly in the last 1500 RPM.
THanks,
Eddie

302man · 12-13-2002, 08:55 PM

From what I can tell, the timing taper is wrong. Start out at 30 degrees and pull it back to about 20 for pump gas and about 24/26 for race gas. You can get away with more timing at a low boost level. There is no heat and less boost, so you can use more timing to help torque things up. You always want to pull back timing as things go higher in boost and rpm. Add more gas at a higher rpm too. If you were to look at a wide band, you want to see a slight dip at max rpm. The extra gas cools the charge so its useable boost. I am surprised you are using a speed brain. I have never seen anyone have much luck with them. This help ?

BigEd · 12-13-2002, 10:01 PM

Yes it helps, I listen to people with a proven combo. I'll keep that 20 degree number in mind. Although I do have an intercooler so I consider that too.
I love the Speedbrain though, I like the amount of control I have.
thanks man,
Eddie

302man · 12-14-2002, 01:11 PM

Ed, remeber you had pinging problems, that 26 degrees is probably it, even intercooled. Thats why I said go to 20 degrees. Its safe and then you can work your way back up when you know its good in all types of weather.

12-08-2002, 08:43 PM	#1
BigEd Registered Member Join Date: Mar 1999 Location: Lexington, SC Posts: 56	Blown head gasket? Crap!!. I think I blew a head gasket. I went to check the oil and it had the dreaded foamy look to it. I'm running 10 pounds of boost and was a little lazy about getting rid of my 3000-4000 pinging I usually get in the winter time. Car is running fine. I'll do a compression check tommorrow. This will be a good excuse to port the heads while I have them off. Eddie __________________ Black 94 GT 5 speed. 10# Procharger, E cam, 2 chamber Flows, 3.73 gears, MAC offroad H pipe, MSD 6AL, SpeedBrain 12.94 @ 104MPH

12-08-2002, 09:16 PM	#2
Coupe50h Registered Member Join Date: Aug 2002 Location: SanAntonio, Tx Posts: 957	yea my friends 347 blew one and we really didnt notice until e.t. slowed, then we knew something was wrong, and checked the dreaded milky oil, yea while its apart take a die grinder to the heads and start cutting. __________________ X-Texas highway patrol ssp 1990 coupe - exploder Gt-40 iron heads, Explorer intake, 19 lber's. E-cam. crane 1.7 rollers. 190fp. 75mm maf. 65mm tb, tubular subframe connectors, mac cai, Asp crank pulley, T-5, king cobra clutch, flowtech 1-5/8 unequals, mac X-pipe Frpp driveshaft, lakewood Lca's. race weight 3,160 12.69 @ 107.35, 1.71 60' 26x8.5 drag's 3.90 gear 13.20 @ 106.91 - 235/60/15 firestones 2.3 60' 3.27 gear

12-09-2002, 04:53 PM	#3
302man Registered Member Join Date: Jul 1999 Location: INDIANAPOLIS Posts: 404	Port the heads and find out why it happened and fix it ! If this has been happening for sometime, when its cold, and you only blew a gasket, you are lucky. There are cheap ways around pinging if you need help. __________________ old S trim combo 10.13@ 135 New YS combo = 680RWHP (no times)

12-12-2002, 06:10 PM	#4
BigEd Registered Member Join Date: Mar 1999 Location: Lexington, SC Posts: 56	Yea, I'm trying to decide on porting my heads, or getting power heads or going all the way with some 165 AFR's. On a budget you know. I've got the Speedbrain and I did knock the timing back to get rid of the ping but it must have been too late. Thanks for the input. Eddie __________________ Black 94 GT 5 speed. 10# Procharger, E cam, 2 chamber Flows, 3.73 gears, MAC offroad H pipe, MSD 6AL, SpeedBrain 12.94 @ 104MPH

12-12-2002, 09:02 PM	#5
BigEd Registered Member Join Date: Mar 1999 Location: Lexington, SC Posts: 56	302man, I did end up backing off the timing but it was too late I guess. I think the colder more dense air leaned me ought because the injectors are already maxxed out under boost in hot or cold weather. My fuel pressure already goes over 100psi under boost. I just need bigger injectors. For now I have lowered the timing to 26degrees in that region of pinging(detonation?) Man I just noticed your times. That is fast! __________________ Black 94 GT 5 speed. 10# Procharger, E cam, 2 chamber Flows, 3.73 gears, MAC offroad H pipe, MSD 6AL, SpeedBrain 12.94 @ 104MPH

12-12-2002, 09:23 PM	#6
sn95gt19 motors done......woohooo Join Date: Mar 2002 Posts: 799	sounds to me like you were running really lean, if your injectors were at 100% hopefully its just your head gasket, if it is your dam* lucky. good luck __________________ 95gt lazer red (98 cobra clone) Rice Haters Club Member #116

12-13-2002, 11:13 AM	#7
302man Registered Member Join Date: Jul 1999 Location: INDIANAPOLIS Posts: 404	Big ed, I would most definetly look into injectors. 26 degrees is on the high side of pump gas for timing. Are you running any kind of boost retard ? __________________ old S trim combo 10.13@ 135 New YS combo = 680RWHP (no times)

12-13-2002, 04:44 PM	#8
BigEd Registered Member Join Date: Mar 1999 Location: Lexington, SC Posts: 56	302Man, Here is my Spark curve for 100% load WOT. Advance 26 26 26 26 29 30 27 25 RPM 2500 3000 3500 4000 4500 5000 5500 6000 In the Speedbrain. this is total advance including the 10 Degrees static. I taper back down over 5000 because boost is building so I am retarding timing when boost is building. Is this way too much for supercharging? What would you go with for timing in the range I have listed? My boost starts at a couple of PSI at 3000 RPM and builds in a slow curve rising rapidly in the last 1500 RPM. THanks, Eddie __________________ Black 94 GT 5 speed. 10# Procharger, E cam, 2 chamber Flows, 3.73 gears, MAC offroad H pipe, MSD 6AL, SpeedBrain 12.94 @ 104MPH

12-13-2002, 08:55 PM	#9
302man Registered Member Join Date: Jul 1999 Location: INDIANAPOLIS Posts: 404	From what I can tell, the timing taper is wrong. Start out at 30 degrees and pull it back to about 20 for pump gas and about 24/26 for race gas. You can get away with more timing at a low boost level. There is no heat and less boost, so you can use more timing to help torque things up. You always want to pull back timing as things go higher in boost and rpm. Add more gas at a higher rpm too. If you were to look at a wide band, you want to see a slight dip at max rpm. The extra gas cools the charge so its useable boost. I am surprised you are using a speed brain. I have never seen anyone have much luck with them. This help ? __________________ old S trim combo 10.13@ 135 New YS combo = 680RWHP (no times)

12-13-2002, 10:01 PM	#10
BigEd Registered Member Join Date: Mar 1999 Location: Lexington, SC Posts: 56	Yes it helps, I listen to people with a proven combo. I'll keep that 20 degree number in mind. Although I do have an intercooler so I consider that too. I love the Speedbrain though, I like the amount of control I have. thanks man, Eddie __________________ Black 94 GT 5 speed. 10# Procharger, E cam, 2 chamber Flows, 3.73 gears, MAC offroad H pipe, MSD 6AL, SpeedBrain 12.94 @ 104MPH

12-14-2002, 01:11 PM	#11
302man Registered Member Join Date: Jul 1999 Location: INDIANAPOLIS Posts: 404	Ed, remeber you had pinging problems, that 26 degrees is probably it, even intercooled. Thats why I said go to 20 degrees. Its safe and then you can work your way back up when you know its good in all types of weather. __________________ old S trim combo 10.13@ 135 New YS combo = 680RWHP (no times)

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