Greetings everyone. I have a 2000 C5 with 160,000 miles on it, so I was looking to freshen up the motor. I'm looking to compete in Solo 'A' Stock this year, so I'm limited in the replacement parts I can use. The rules state that I can only use current factory replacement parts. When I looked up the part numbers for the GM Goodwrench LS1 crate motors, the website says that they are no longer available from GM. When I look at the LS1 Performance Parts assembly, 17801267, it says this part is no longer available and only longblock part number 89017352 is available. When I go to that page, it's also discontinued. Also tried part number 89017548, but it was also replaced by 89017352.

Does anyone know what the official GM Goodwrench replacement engine is for the LS1? It has to be the factory recommended replacement crate engine to be legal to compete.

 

LS3 crate.

since when does the SCCA follow reality of supply ?

 

http://store.chevroletperformance.co...ue&category=LS

 

160,000...that's it?

I've got a modified engine with 214K on the clock. Top end is fresh (@190K), but the rotating assembly is original. 412 to the tires...

The weakest link in the stock motor is the valve springs.

 

If it hasn't been taken to a road course or drag raced a lot and otherwise taken good care of, you'll be fine on the stock 160k motor for autocross. You don't normally spend a lot of time near redline during an autocross in a Vette anyway.

edit: As stated before the valve springs are the "weakest" link, but that's usually only a problem for track events.

 

Yeah, I've already ordered some replacement valve springs and related stuff. I can hear a little valve float once the motor gets above 5000 rpm or so.

I wasn't planning on replacing the engine so much as I was wanting to see if there were any newer parts on it that might give me a few extra horses. For example, I understand that after 2000, all LS1's switched to the LS6 manifold. I assume that's the main reason the latest LS1 crate motor is rated at 350/365 while my motor's rated at 345/350. While 5 peak hp isn't much, 15 ft/lbs of torque is huge - it's enough to make the car feel like it's being driven by a jockey instead of my 250 lb behind.

I've also got a steep learning curve ahead of me on the suspension upgrades. I was a pretty serious drag racer for about 10 years, so I know about engines, rotating weight, and such, but not so much about suspension setup.

 

As far as modifications go, the LS1 responds remarkably well to a small cam. I switched out the 853 heads for 243 heads off an LS2 (solid exhaust valves instead of hollow sodium filled), added the LS6 intake and put in a small 222/226 0.600 115LSA. Along with long tube headers, bigger injectors, push rods, LS7 lifters & trays.... the power, throttle response and sound are amazing.

I also replaced a bunch of gaskets, the damper (mine had the wobble), both of the tensioners, fluids, belts... since the motor was apart. In hindsight, I should have had the 243 heads worked over before I put them on, but the bills were climbing higher than expected.

 

Stone, not sure what level you are planning to Autocross at, but some things you are talking about are getting into the illegal areas. No update/backdate in stock. Honestly if you are new to Autocross, get the car reliable and learn to drive it. Spend more $ on driving schools and seat time than modifications. The stock class prep is pretty well known for suspension. If you want to freshen up your motor, do it to YOUR motor but be careful but what the mechanics/machinist are doing. Things that seem little to them often times isn't legal. In 20 years of national level auto crossing I have only rebuilt 1 motor and it was because it broke a ring. (not on course or related to autocrossing)

Go to the Autocross /roadrace section for more input also.

Glen aka MeHurricane

 

You might check to see if your car has the Pup Cats. They were required for all Corvettes (2000) sold in Calif and the other state that mandated the CARB specs. Way back then, as i recall we had a GM eng tell us at the local Corvette Club meeting that the 2000 cam was bigger that 97-99 and could add 5 more hp but they adv the hp for the Pup Cat cars (345) as the standard.

 

Glen,

That's why I'm asking. I'm not averse to gray areas, but I don't want to stray into the black. What is the rule for a replacement engine? From what I read on the SCCA website, a replacement engine has to be the factory recommended part for that year of car, in this case the GM Goodwrench engine, and specifically NOT a GM Performance Parts only engine, unless that is the general replacement recommended by the factory. Is that correct, or did I read that wrong?

I HAVE to replace the valve springs, I can hear valve float, and the balancer is wobbling so I'm going to replace that. I'm not going to upgrade the injectors, but I am going to buy a set of flow matched stockers to keep the computer from adding fuel or pulling timing at full throttle. Most of this stuff is the kind of thing you do in drag racing when you're racing in a stock class. I'm not so much interested in making big gains in hp as I am in minimizing the losses. The LS6 intake would be an exception in this area, since it is presumably the main reason for the torque increase in the goodwrench LS1 motor. If I ordered a replacement intake from the factory for a 2000 LS1, would GM send me the earlier LS1 intake or the improved LS6 intake as the stock replacement? If the latter, doesn't that make it legal for competition?

As far as your recommendations on seat time and suspension, I hear you. I'm taking a beginners' class at Dallas Raceway next weekend. I'm going to run the car in daily driver trim for the first half of the season at least, until my budget will allow me to upgrade to DOT race tires and something like the Penske double adjustable shocks. I don't expect to be competitive above a regional level this year, and probably not even that; however, it's not as much fun if you're not trying as hard as you can.