Another head gasket

[Blacktop]

Well I have gone through another head gasket. I am getting sick of taking the engine apart. This time I took the hole engine out of the car. My question I have is what would cause this to happen?

In the picture you can see the little passage way that the coolant made to the lifter valley area. I torqued the lower intake to specs was running 10 degrees timing between 1 and 1.5 on the BTM ,42lbs of fuel pressure. Is this caused by detonation? If so what am I doing wrong? Any help greatly appreciated

[Chuck]

What was your set up like the first time you blew a head gasket? If it was the same timing set up that you have now I would say that your BTM is junk.

Did you get the heads resurfaced to make sure they were perfectly flat after the first one blew?

What kind of fuel do you use?

[MikeyMustang]

have you ever had your car on a wide band o2?.....you could be leaning it out.....

there are a few things that can cause detonation wich is probally your trouble

1 octain with higher compresion AND a blower your effective compression will increase

2 heat air temp

3 timing....10 deg should be good

4 if the deck surface or head surface is not true

things that can help

1 octain..NOT octain boost...RACE GAS!...UNLEADED so not to hurt your o2 sensors....i use 100 octain mixed with 94 50/50..insurance!

2 colder range plugs

3 cooler air intake

4 check btm....possibly pull timing with a chip on top

5.make shure you have enough injector AND fuel pump..i sugest a gss340 intank...thats all i use for 460 rwhp over 500 at the crank

6 bypass valve

advanced way to detect detonation (sometimes can not be heard)

http://www.autospeed.com/cms/article...estions&A=0348


good luck


Mike

[Blacktop]

Thanks for the info. How much boost are you seeing to make 460HP? How can I get the air intake temp down with a novi2000 setup? They don't make an intercooler kit for a 93 5.0. Is there a special kind of race fuel I should look out for? I do remember reading that there are many types of race fuel.

[MikeyMustang]

i see 10-11 with a Novi 1000 with a f150 pully and a 2.75 on the blower....your way ahead of the game with the Novi 2000!........big thing is i would get rid of the 190 pump and get a Walbro GSS340..... and possibly you won't need the TREX


as far as race fuel any race fuel that is unleaded and above 100..but its expensive! like 5 bucks a gallon but it beats changing headgaskets

as far as air temps thats tuff ...vortec used to make a inline cooler box for a fox.....but the main idea is try not too boost it badly on a hot day unless you have race gas or pull timing.....detonation is tuff..lots of variables...like bad gas and a hot day=BLOW HEAD GASKETS!

MOST IMPORTANT.......go get dyno tuned with a wideband o2! and to be safe make your af ratio about 12:1 or 11.5:1...some say 12.5....but i like to be safe

good luck

Mike

[Blacktop]

I forgot to update my profile. I don't have the t-rex anymore and I did install a gss340 255lph high pressure intank pump. Now that I have more information on what causes detonation I think that mine was caused by it being too hot out and not pulling enough timing. I think that I got a little greedy on a fewe hot 90 degree days. What's the compression ratio of your motor? Do you run a FMU? What do you set your FP at? Sorry for all the questions. I'm just trying to get the whole picture of other peoples setups so I can learn from them. What is your setup anyway? Now I have to find out where they sell race fuel in CT.

[Chuck]

My comp ratio is 9.5:1

I have 42# injectors with the pressure set at 45 psi with 0 vaccuum.

I run 24 total with 94 octane not mixed but with the spout out. I see 10 psi of boost. I do use race gas at the track though just for added insurance.

Running with the spout connector out might help you because in the mid range you can get timing spikes over 40*, it is sometimes referred to as tip in detonation.

I have been experamenting with it and my car runs better with the timing locked at one setting anyway, so I leave it there all the time now. I used to only do it at the track.

I have seen no ill side affects of running without the spout connector as of yet.

[regattacoupe]

torco 110 race fuel is 02 safe and kicks butt!

[regattacoupe]

before you re install your heads clean both mating surfaces with a die grinder if you have the resources.

[MikeyMustang]

I wouldnt use a grinder to clean it i would use MILD SCOTCH BRIGHT PAD soaked with brake cleaner and then wipe all mating surfaces with break cleaner till the rag comes back clean..and check for trueness with a streight edge diagnally on the head with a feeler gageset at .004 i think(consult your manual)

Chuck is correct the EEC can add as much as 40deg total without you knowing!...but i never tried the pull the spout trick some swear by it


my comp ratio is about 9.5:1 also and i am not shure what my fuel pressure is without the vaccume hooked up but i see about 40 psi at a idle ...i am running 38# injectors...but they are getting at there limits


hope this helps

Mike

[Blacktop]

I found this write up on timing in the corral. You have to weed through the garbage but over all its good reading. It seems a lot of people run with the spout out.

http://www.corral.net/forums/showthr...ghlight=timing

Does anyone now exactly what else is affected when you run spout out?

Also how do you guys see your timing marks. Its almost impossible with the novi2000 and a 10 rib belt. I have to cover my car with black plastic to make it dark enough for the timing light to reach the marks. I just can't get the light close enough.

[5150 LX]

Originally posted by Blacktop
Also how do you guys see your timing marks. Its almost impossible with the novi2000 and a 10 rib belt. I have to cover my car with black plastic to make it dark enough for the timing light to reach the marks. I just can't get the light close enough.

Not sure if this will help but, the timing marks on my old stock balancer were a pain to see. I took some white spray paint, shot a light coat over the marks and let it sit up for ~10 minutes. I then cleaned the excess off with laquer thinner. End result left paint only in the indentations and made it a heck of alot easier to read the marks.

[regattacoupe]

i use a special pad designed to clean aluminum......it's pretty slick....and very mild.