Intake manifold design on FE3 mazda motor

[boostedfe3]

OK guys I know this is non DSM related but Iam asking around to see why I keep blowing my head gasket on cylinder #4. I have a mazda miata with a 2.0 mazda fe3 motor. I have 850cc injectors, 2 walbro 255hp pumps in the tank. One pump is feeding one end of the fuel rail and the 2nd pump feeds the opposite end of the rail with the return in the center. My A/F is between 11.2-11.7 so its pretty rich for a street tune. Fuel pressure at idle is 38psi. Turbo is SC61, with spearco intercooler. Im having these headgasket issues with 10-15psi of boost and my timing with 15psi is 15degrees total timing. Im suspecting my intake manifold because it is box type with no velocity stacks and it does not taper down towards #4 like the magnus manifold does for the 4g63. My thoughts are that most of the pressure is going towards #3 and #4 causing a lean condition. I just need to know if that is what you would expect also. The link provided will show pics of the motor with the intake installed. I could definately use any insight you guys can provide. Thanks in advance. http://img.villagephotos.com/p/2003-3/129289/FE3Miata037.jpg

 

[anconover]

theyre are dsm manifolds with no stacks that dont have tapered plenums. Ever have your head checked for flatness or resurfaced? same with the block?

 

[boostedfe3]

yeah i had the head checked last time and had it resurfaced. I havent checked the block yet but when i pull it apart I will check it also. I mean a gasket dont last me 100 miles. thanks fo r the help.

 

[GSX_RCR]

Are you re-using stock headbolts?

 

[Bastard1g]

What kind of headgasket are you using? go on probetalk and talk to "fallguy" he has a low 11 second probe with an fe3 motor that could help you with your issues.

 

[boostedfe3]

I know Fallguy real well. We have worked together on some stuff. I currently use a stock headgasket which I have never really had problems out of before. See I had this motor in a ford probe gt and never ran into this issue with the motor before I switched to the miata and sheetmetal intake. Fallguy and I on the probes used stock intake manifolds. Oh yeah I have ARP head studs torqued to 100ft lbs.

 

[GRNDSM]

This isn’t Advanced 4G63t Tech > Extreme Tech Forum !!!

Thread closed!