I Read the FAQ section about the reasons why GM went back to the traditional cooling style Block-Heads. Has anybody Changed the LS1 to reverse cooling? If so what were the results etc.

Also, those casting plugs on the LS1 heads (ends) on the exhaust side look inviting. The Smokey Yunick method of the Y head scavenge may be an option as well.

Looking for your thoughts...


Art

 

I remember an article in GM High-Tech Performance magazine soon after the LS1 came out. I wont repeat the numbers that I remember from the article in case my memory is wrong... Hope this help you find what you're looking for, if no-one comes up with an answer for you, I may go through my back-issues.

 

they are traditionally cooled

 

I think you missed the point of Art's question.

He stated that LS1's are traditional cooled, vs the reverse cooling of the previous engine design (the LT1). His question was: Has anybody converted an LS1 to reverse cooling, and if so, what did it do (power, cooling, whatever)?


If I remember right, reverse cooling was worth some power (not sure how much), but the headaches associated with it were too large (at least for the bean counters at GM responsible for paying for such headaches under warranty). Which would imply that there is power available in the LS1 by going to reverse cooling assuming you can keep the air purged out of the system (and any of the other potential problems).

Sadly, I don't remember where I read the statement about reverse cooling being worth power, or any kind of quantification of how much (2hp or 20hp). So, sadly, I can't answer Art's question at all.

'JustDreamin'

 

I beleive it was an overlooked patent, not a warranty claim.

 

Are you saying someone else already had a patent on it, and that is why they stopped using it after the LT1?

 

the reason they went back to traditional is it was a bitch to bleed the cooling systems on those lt1s from what i understand

 

I actaully blew the head gaskets on my old 94 LT1 Camaro because I did not bleed it enough and it overheated in Laguna Beach, CA. I ended up spending my two week Christmas break changing the head gaskets on the that car

 

Thanks for the info.

The air pocket issue is quite a big concern. I'll try to look into the exact coolant passage shape in the heads, and find out where the peaks are to trap air,(would make things worse) if there are any at all.

One problem with the small block Chevy, and now I believe the LS*, is that with both heads flowing into a single port, then into a hose back to the rad, each head does not flow at the same time. This was something Smokey Yunick investigated. What happens is that as the coolant heats up and begins to flow, one side(head) will heat up faster ie. hotter, with more pressure. This greater pressure makes only the hotter side flow because of the greater pressure. Then, as the hotter side flows, it cools down enough, aqs the non flowing side heats up. There is then a transition of flow. In the end what happens is an alternating flow, resulting in an inefficient system, and hotter heads, and less compression.

What "Smokey" did was drill holes into the ends of the heads edging towards the exhuast side ( hottest ) . Tapped and installed piped fittings with hoses and a Y juction to a main rad return hose. This allowed the heads to flow more effiently(from the front of head) and to flow simultaneously, resulting in more stable head temps.

It would seem that the LS1 heads are ready made for this mod, with the casting plugs in the exact optimum area.

"Smokey Yunick" for those that don't know was yester years David Vizard in the racing/performance genre. He has many patents including the extended tip spark plugs we all enjoy. When I read something of his, I take it as gospel. Though some new technology and metalurgy has changed from his days. He tried to get GM to use a reverse flow setup for many years.

Your thoughts are appreciated...

Art

 

Evan's Cooling Systems holds the patent on reverse cooling. They have been in a dispute with GM for years over royalty payments they feel they are owed.

 

I never have any problems bleeding my coolant system on my car. It can become a mess (coolant spraying all over the place when the air stops coming out) but purchasing a nifty little bleeder valve that I can attach a rubber hose to makes it all the easier.

Matt

 

Here is some info on that if anyone is interested.

http://www.evanscooling.com/evansvsgm/nytimes.htm

 

Here's something for you to ponder. From the 1998 Pontiac Firebird sales brochure:

 

So, regardless of whether GM aquired trade secrets legally or not (which seems like it will be disputed for a couple more years), the original question still remains unanswered.

Does anybody have any information on whether the LSx series engines would benefit from reverse cooling? Anybody do any experimentation / research on this? Anything? I'm certainly interested in the outcome.

'JustDreamin'

 

Joe Prince (surprised nobody has brought that up yet) did produce a reverse flow electric waterpump, slightly before the Meziere street waterpump came out. I am not sure how many units were built, but I saw pictures and dyno charts. Seems the gains on the dyno weren't too far off from the Mez units tho, at nearly twice the price ($800-$850 was his price target, IIRC).

Search for JPR EWP here, that's bound to dig up something.

Oh, and don't mention JPR in any new posts. His business failed miserably in a huge crapstorm.

 

Check this months Hi-tech and performance. One of the nitrous cars is reverse cooled

 

Very interesting article....thanks for posting.

 

There is some power and reliability in reverse cooling. Any one even notice LTx cars had more base CR then LSx car?

I have never had a problem or issue bleeding a LT system

 

so then since there is some sort of power gain how is this possible with our motors? do we use those plugs in the back of the head or what? i'm interested in all that could possible involved in this swap

 

ok guys so you are saying that the LSx is traditional flow from block to heads?? I have been told prefusely that it is reverse heads to block please let me know .