Attended a local car club outing in which Lou Gigliotti is a fellow member. Ended up in a LS7 conversation sparked by Brent Bauer's statement that you could get 400 cfm flow from the LS7 heads, but it actually hurt performance.

In asking Lou what they did to the LS7 heads he confirmed the same exact thing. Except for adding different intake valves because the factory uses lash caps which Lou had seen some come off, they leave the intake section alone. They however extensively rework the exhaust side by adding larger valves and porting as in Lou's words: "Chevy put in a restrictor"

Once that is done, they do a few little things to the car but by adding headers and playing with various camshafts he is able to get as much as 620 rwhp. Evidently he feels the intake may also be a restriction on the engine as he is getting a prototype intake to test but feels there is more power to be had in "stock" porting.

Makes me a bit jealous to say the least.

Lou and I have not always seen I to I on everything in the past but he had his wife and son at the outing. Nice family, wife's sweet, kids sharp…..Hope he does well in the 24hours of Daytona where he'll be putting a set of those heads to the test in a Corvette.

 

Denny,

Lou's pretty much got the hot setup right now for the LS7, it's a very well put together package. The sick thing is there is probably even MORE left in them! Time will tell. I've said that Mike Chapman is a smart guy and people "fixing" those LS7 castings don't seem to be able to do anything other than win flow bench races. Looks like whoever is doing Lou's heads gets that, and obviously power follows.

Bret

 

That's extremely interesting. Thanks for the information.

Rich

 

So they aren't using lash caps on titanium intake valves and they come off with a hydraulic cam? Are they using valves with hardened tip inserts? I can't understand how a lash cap would create a problem without massive valve float.

 

No the hard tips come off of the valves and all hell breaks loose.

Bret

 

Lou said they had seen them come after someone missed a shift.

 

that is what rev limiters are for... i guess that he shifted to the wrong gear.. like 3rd to 2nd at 7000rpm?

 

Dunno.. but if you turn on the TV the 24 hours of Daytona is under way and you can watch him. My bet is there is a lot of 3rd to 2nd @ 7000rpm going on.

Literally some of the best drivers in the world with some of the best equipment in the world. Man, would I ever look good sitting in one of those cars. Can see it all now......"HI MOM and I'LL BE GOING TO DISNEY LAND".

 

Yea, I think most people miss out on the fact that cylinder head flow can be alot like carburetor flow ratings. Your engine may only need so much. If the port can flow enough air to meet the engine's demands without causing a restriction, then increasing flow beyond that will not produce any gains. For a long time, most people never reached that point since most of the available heads were still a restriction. Now that 370 cfm heads are widely available, people still think that a higher head flow numbers = more power, so they must be ported.

 

If he's running a Corvette in the Rolex 24, he's not running LS7 heads on it. The GT class is limited to stock LS6 castings with no porting. They're also limited to the stock LS6 intake & throttle body. Not trying to be a smarta$$, but I've built these engines for two different teams during the last two seasons.

They can also run an LS2(more cubes), but it must come from the Grand Am designated builder as a "sealed engine", and must use an inlet restrictor.

 

Learn something everyday. When I talked to Lou he told me he had the choice of two cars to drive. One was a Mustang that he said didn't handle very well or a Corvette. My assumption was chevy would be running a LS7 which is a production car. No wonder Porche does so well then.

If you've built the engines and they use mostly stock parts, what is it you do to them?? Cams?? Is there a lift or duration limit?

 

I completely agree!!

I got to thinking about it and why wouldn't 360-370 cfm be enough for my goals?(600 rwhp/700 fwhp) I have seen more than 1 408-427 w/ afr 225's w/ 550 rwhp and that is with 320 cfm. I would think that the extra 40 cfm can certainly make 50 more rwhp

 

You can use an aftermarket rotating assembly, but all components must be of similar weight to stock. Ti valves & retainers, aftermarket rockers & springs, and dry sump oiling are allowed. We spend a lot of time on the flow bench sorting castings and tweeking the valve job. Aftermarket cam is allowed, but must have LS6 stock specs.

There are some pics of a completed engine in this photo album...
http://new.photos.yahoo.com/masnart3...60762344161365
Just in case you wondered, the photos of the LS1 shortblock in the album are not a Rolex engine.

 

Good info. Thanks for sharing!

 

When you flow different production heads, what kind of variance do you see? This used to be an old Super Stock trick of taking production components and only using those with the best spec's. Evidently doing this is still alive and well.