Yep, I pulled the heads off the used LS1 I bought to do my v6 to v8 swap, and the lower row of steam holes were plugged on both sides....

Anybody else run into this?

Would it hurt anything to slightly enlarge those holes on the new gaskets to minimize this in the future?

 

Do not change the size of the coolant holes in the gasket. You will alter the coolant flow through the block.

I suspect the previous owner never changed the coolant. Probably used Dex Cool. Dex Cool has caused many problems with cooling system components, corrosion, plugged passages, leakage, etc.

Clean out the coolant jackets as much as possible before putting it back together. Use good coolant and change it every couple of years.


Steve
Race Engine Development

 

What is good coolant? Should we use an alternate to Dex Cool?

 

Steve, what coolant do you suggest?

 

I recommend Evans NPG R which will eliminate any corrosion problems - the only recommended coolant for any of the MID kit installs I do by the way. It is used straight, no water at all must be in the system. Pressure cap is reduced to 7 lbs. or less so there is much less chance of springing a leak or blowing a radiator hose. The type R coolant is good for 10 below zero and will not boil until 400 degrees. The high boiling point guarantees there will be no steam pockets in the heads thus reduced chance of detonation damage. It is expensive but it does not evaporate and does not need to be changed.

Evans also has brand new pumps now for the LS engines. More flow than the stock pumps and more even flow per bank than the stock piece. Evans sells high output inlet style stats in 160 and 180 degree opening. A kit is available to eliminate the inlet style stat and replace it with an outlet stat in a separate housing. This boosts coolant flow substantially over the inlet style stats.

Stock GM pump and stat flows 55 gallons a minute. Evans pump and Evans inlet stat flows 85 gallons a minute. Evans pump and outlet style stat flows in excess of 120 gallons a minute. A good measure is that one gallon of flow per minute will cool about ten horsepower. So 55 gallons a minute is sufficient for 550 horsepower. Since the engine rarely produces this much power for any length of time this amount of flow is more than adequate.

I'm a dealer for Evans as are several of the other sponsors.

Steve Demirjian
Race Engine Development

 

PM me a price on this coolant, enough needed for the LS1 coolant system

My DexCool always gets that sludgy type consistency at the base of the radiator.

 

send me the same info on the coolant and 160 t stat please

 

How does that coolant react with dexcool? (ie- if some is left hiding somewhere). I know "traditional" coolant makes a nasty sediment & sticky mess if you mix the two.

Also, where can I get this new coolant...and a lower pressure cap...

 

The system has to be completely cleaned out of the old coolant and dry before installing the Evans coolant. This includes block, radiator and heater core. Especially important if the system has Dex Cool.

Drain the system, fill with water and a good commercial flush. Flush it out as best you can. Evans tells me that the best way to get most of the remaining water out is to remove the water pump and jack up the back of the car. If you can get the block plugs out that will help. Blow out with compressed air. At this point you should have a clean system with a bit of clean water only left - none of the original coolant

Evans has a special flush to help get any remaining water out. Prep Fluid which costs $16.50 for a gallon (you will need three gallons to get enough into the system to circulate). This will combine with any remaining water. Drain the system as above. Any of the flush left behind will mix with the Evans coolant and do no harm.

It is obviously a lot easier to switch over if you are doing the engine over and have it out of the car. Then you are starting with a clean block, you probably have the radiator out of the car and can clean and dry that so all you have to worry about is the heater core and hoses.

Radiator caps are available from Evans as well. Zero pressure and seven pound caps are $7.95. They have a billet seven pound cap for $29.95

High flow thermostats are $49.95. They just came out with a high flow 160 degree stat. I believe the price is the same but not positive.

NPG R Coolant is $19.50 per gallon in case lots of four. I can have only case lots drop shipped to you.

Evans LS1 LS6 new pumps, no core charge, are $469.95, ceramic coated $594.95. Pumps come with a pulley which is slightly smaller in diameter to speed it up. Belts are $49.95 through Evans.

Note that the prices for stats and caps may be slightly higher. They don't list those prices in the newest price sheet. All the other prices I have quoted are from their newest sheet.

You can order any of these products through me if you reside outside of Ca. I am wholesale only in Ca. I take checks but no credit cards.

You can order direct from Evans as well. www.evanscooling.com or 1-888-990-2665

Steve Demirjian
Race Engine Development