TOP END REFINISHING

[Schrade]

Anyone know if there's a spec thickness for heat sink paste?

Or if it's only for heat capacity, of the compound?

[mike100]

Originally Posted by Schrade

Anyone know if there's a spec thickness for heat sink paste?

Or if it's only for heat capacity, of the compound?

There may be a spec, but most people apply it with a razor blade or sharp spatula edge etc. At my job, we make various high power inverters and the IGBT transistor and diode packages get the thermal paste applied through a silk screen to the copper heatsink. Use a razor blade edge- the extra just squeezes out of the edges anyhow.

[Franke]

Mikes right but just for sake of a spec - info from the FSM indicates .25 grams in 4 places. (page 6e3-c4-9)

[Z06scentair]

Originally Posted by Schrade

Thanks Mike...

Only had 1 syringe of CPU heatsink pasts; gotta' hit the 'Shack...

Great glad you posted that I was wondering about that white paste....guess I need to go get some as well.

[mike100]

The secondary ports get dirty because they don't run all the time.

[mike100]

I will get the source of the thermal compound I used. It comes in jars that could do dozens of devices. Been running it for a couple years with no problems.

Pretty much the same stuff they give you for GM HEI ignition modules for the distributors. I learned a good lesson once- don't use the paste and the car will run for about 2 hours before failure.

[Dynomite]

Before you tighten down the Plenum (with Plenum tipped up in front) and ALL vacuum lines, and DIS module connections in place....check your vacuum systems.

With all vacuum lines connected, turn key on and listen for vacuum pump to shut off. If it does not shut off, start at the closest vacuum line to the vacuum pump disconnecting the line and holding your finger over the end. If the pump shuts off the leak is on other side of that. Go to next fitting and do the same until you are past the leak wherein the vacuum pump will NOT shut off. You have now located the leak.

Also check your HVAC and Cruize Control Vacuum System (check ALL connections). Also check your EVAP Purge system connections (charcoal canister which is under drivers side headlight on your 90'). That single small vacuum port under front of plenum facing rearward (90' only) is for the Evap Purge System. The second larger vacuum port on drivers side lower front of plenum is the main vacuum line for the Charcoal Canister. The second Vacuum port right next to that Charcoal Canister port is your PCV Vacuum port.

With the key on, ground the pink wire in the green connector (third from drivers side) on ECM. Use a small finishing nail stuck in alongside the wire connector with an alligator clip pigtail attached to the end for grounding. This will activate the Secondaries which you can watch with the plenum tipped up in front before you bolt it down. This after you are sure you have NO vacuum leaks in the Secondary System.

I promised GC I would not mention any modifications .....but you should eliminate TB coolant so you do not have to mess with coolant every time you remove the Plenum......DO NOT TELL GC I suggested this

Vacuum Systems 90' and 91' (Secondary and Cruize/HVAC)

[efnfast]

Originally Posted by Schrade

Anyone know if there's a spec thickness for heat sink paste?

Or if it's only for heat capacity, of the compound?

Schrade, where is this heat sink paste going to be applied? TIA - Steve

[XfireZ51]

Schrade,

Just do about 4 dabs on the IM, then smear it over the mounting area. Just make sure it covers the entire area so there are no hotspots.

[efnfast]

Dom, this is the thing bolted to the bottom of the plenum? I'm soon to change my plenum, this sounds important.