KiwiKid

Hi all LS engine fan's, I'm a recent [4 years] convert to LS engines and like many of you I have had to learn the hard way.

I dived in the deep end and purchased a crate engine LS7, as the proposed controlled spec engine for a prototype car road racing car we developed for a new category of 4 door tin-top racing here in New Zealand, known as V8Supertourers, which is modeled on a highly controlled version of the Australian V8 Supercar Series car, in order to save on both build and running cost's but have similar levels of performance.

Under my tenure we built 22 V8ST car's, including the prototype V8Supertourer, all with LS7 stock standard crate engines that we purchased through Chuck at Pace Performance Ohio. At last count we had purchased close to 30 complete LS7 engine's, and at least 15 long [Service] engine's.

Our problems with the engines started at the very first race meeting were we had 16 V8ST race cars on the grid [8 with Holden VE2 Body panels, and 8 with Ford Falcon FG Body panels] the problems started with the close drafting nature of such a controlled category we each competitor has the same potential lap time, and with track temperatures around 40ēC a number of cars engines ran hot on both the water and the oil, something we had not experienced at all with the single prototype car that had always run on it own.

I could and probably should right a book on the drama's, engine blow ups etc, and the instant experts who suddenly appeared with how to fix it solutions many of which were adopted and in some cases showed small gains.

I became more and more convinced that the principle problem was that any engine rev's higher than 6,000 rpm that the scavenge g'rotor was incapable of returning the same volume of oil that was being delivered by the pressure side of the standard so called OE dry-sump pump, and as such the volume of oil in the sump was so excessive that the crank and rod's acted like a giant egg-better and beat the oil into a highly aerated super hot froth, which was a recipe for disaster.

In desperation we mandated a maximum RPM of 6,250 and limped along for the first year with out any further blown engines, until I was able to gain sufficient competitor "buy-in" to have Bill Dailey from Dailey Engineering design and build us a 3 stage, integrated Pump and billet pan to fit, without any modification's just in front of the left hand engine mount.

This was an immediate success and bought both the oil and water temperatures into near perfect operating temperatures.

Once we were on top of the temperature and oiling issues, we were able to focus on the occasional catastrophic [rod through the side of the block] engine failures that were were still experiencing. By analyzing the onboard data we finally determined that RED-MIST downshifts possible even with our sequential 6 speed Quaife gearboxes, were responsible for causing a momentary over-rev under braking compression, which literally pulled the wrist pin out of the piston gudgeon boss's.

We were about to bite the bullet and mandate a change to Mahle's off the shelf forged piston, when we discovered quite by chance the GM had secretly introduced a modified hypeautectic piston, that you had to buy along with a slightly modified Ti rod to suit the strengthened piston's. We also discovered again by chance that GM were fitting the new rod and piston, as standard to their so called Service engine [long engine in our terminology] which made a lot more sense to purchase because all the wear parts were new at a reasonable, at least to us cost of US$10,500 less core cost, if you had one which we didn't.

This Service engine solution, though only a bandage in my opinion meant that those competitor's that had not lost an engine, didn't feel forced to tear down their engine in order to fit a forged piston even though we were convince there would be no performance advantage.

Along the way we discovered the reason for almost all the ti-rod's big end galling when the side's touch each other, this lead us to allow controlled Blue printing to deal with the unbelievable bad tolerance GM allow in the build of their engines, which is bordering on Corporate negligence at least in my opinion. We found little-end wrist pin clearances down to 0.0003 and up to 0.001.5 !. As the little-end 'steers' the rod its no wonder the big end's side's get into contact at some point in time given the complex secondary harmonic's that exist in all engines to a lessor or greater extent.

We all so found size for size piston and bore's plus badly tapered bores, such a shame with such a great engine, but nothing that a full on blueprint cant fix.

All this said I have become a huge fan of the LS engine and am currently building a normally aspirated 800BHP, 8,500 RPM 3.625" short stroke screamer, with a 4.185" bore, using a GEN4 Truck block and MID wet sleeves from Steve at RED in California. As the build goes along I am happy to share it with all the LS engine fan's on this site, so I will start a new thread on the build in the next few week's.

Thanks for reading my introduction to the LS1 forum.

Mark.