420a stock head bolts???

[matt98eclipse]

Hey guys how much boost can the stock head bolts on the 420a handle???

 

[4glaser63t]

My friend did a 420a turbo setup on his car and was running about 6-7psi but after a few mouths the car started to run really bad not sure what happen.But hopefully this gives you some what of a idea.

 

[matt98eclipse]

Well my buddys car that im rebuilding right now was running 15 on the stock one but he wants to run around 20.

 

[1slow97]

Stock bolts won't last long on 20 psi. I would say stay at 15psi max , till he get's some arp head bolts.

 

[matt98eclipse]

Yea we have to motor almost all the way out right now! In my other post i posted theres pics of the bottem end. He had low compression in one cylinder for some reason!!

Im definatly gonne be installing arp head studs! Whats a good final torque for the arp's on the 420a's
Is it necessary to do the 3 stage step's.

 

[crab1092]

I torqued my arp head studs to 25, then 50, then 70 ft-lbs as the final torque. It seems to be working as i havent had any head gasket problems(knock on wood).

 

[cs82685]

^I torqued mine to 30 then 60 then 90 to finish it off as recommended to me by 2gnt

 

[matt98eclipse]

K thanxs for the help guys! Ill torque them down to 90 and use oil for the lube instead of moly.

 

[awddynamite]

i wouldnt push it pass 80ftlbs on the 420a but i put mine down to a respectable 100ftlbs, i would say 90 is a good number.