As some of you may know I am building a hybrid, LS1 in a thirdgen camaro, but I need some input from the motor builders so I know what to watch out for. As it stands I have a LS1/T-56 with 11k on it being shipped. I will be running LT headers built for this conversion, AS 5.3L Stage 2.5 heads with comp "R" lifters, Texas Speed 7.35 push rods, .030 shims, 977 springs with a F13 cam (230/232 .591 .595 114 LSA). I will be installing ARP head studs for insurance because of the problems I have hear about the bolts being to long and botteming out early. Are there other areas I should watch out for? Am I pushing the stock bottem end to far? (I dont think I am) I have spoke to a few people and was told that "You should build the bottem end too because I spun a bearing after installing a hot cam". I really think his spun bearing was a fluke because I didn't see any mention of this being a problem with these engines. I have heard the connecting rod bolts tend to streach on some of them.
Please put in your 2 cents and give me some ideas of what else needs done with out going to a forged bottem end. If I had the funds I would have went that way.

 

If you already have the engine out of the car, take the extra 30 minutes to install ARP rod bolts.

 

Summit has ARP rod bolts but what ones do I want ARP-134-6006 or ARP-234-6301?
I am also going to order the head stud kit ARP-234-4110 are they the one I want?

 

6301! Only $12 more.

 

If you install rod bolts without having the rod resized, plan on spinning a rod bearing. If someone tells you it's possible and he has done it. He is one lucky fellow or he never did it. The tolerance on the roundness of the production rods is .0005". I guarantee you the production tolerance on bolts isn't any better and when you add in the stackups it adds up to a spun bearing. ARP bolts are great and a good machine shop can hold .0002" on the big end roundness. Failure to resize rods when installing rod bolts is one of the most overlooked mistakes that backyard rebuilders make. That's a little advice from 30+ years of professional engine rebuilding and machining.

 

QuietTahoe,
Thank you for that much needed info. That is the main reason I visit this board! This board has alot of people that have been in the game for years and can point out alot of over looked things. I guess for the time being I will just run the stock bottem end and if things look good I will leave it alone. If I have problems I will pull the engine and start building a forged bottem end.

 

If the LS1 you're getting is an '01 or later, the rod bolts don't really need replacing. GM upgraded the design for the '01 line.

You may want to upgrade the oil pump to one of the many available ported LS6 pieces available via the sponsors. And a timing set while you're in there...I'm happy enough with my JWIS chain and stock gears, too many worries w/ the double-row chains and requisite oil pump spacers.

If your block has tapped holes for the LS6 timing chain tensioner, it's a good thing to have. They're located between the cam and crank gears, on the block.

 

I learn something new everyday, thanks for the info.

I must be one of the lucky ones, because I did replace my rod bolts when I was switching out my K-member and have had no problems. I never thought of a rod becoming out of round, just by replacing the bolt. Oh well, looks like I learned something new for next time around.

 

The rod bolts don't distort the big end of the rod. That results from the stopping and starting of the rod/piston assembly at TDC and BDC. The rod cap locates to the rod on the shank of the rod bolt. The act of removing the bolt and reinstalling bolts and torquing the cap frequently causes misalignment. This very frequently leads to a spun rod bearing unless the rods are resized. The factory spec of .0005 max out of round is only 1/6 the diameter of a hair (.003). You can't intermix rod caps with rods or main caps from one position to another or one block to another. Changing main caps frequently requires align boring followed by align honing.

Also, don't look at a cast crank as a weakness. Nodular cast iron cranks have much more vibration resistance than forged cranks due to their amorphous grain structure. The strength of a forged crank comes from its aligned grain structure, but that is also its greatest weakness. All forged cranks will ring like a bell when you tap them with a wrench (unless they have a crack). Cast cranks make a dull thud. The ringing of a forged crank is caused because forged cranks have a resonant frequency just like a piece of fine crystal (remember the Memorex commercials-maybe you aren't old enough--maybe I'm getting old!!). Just as fine crystal will shatter or crack when the resonant frequency is hit, so too will a forged crank crack when operated long enough at its resonant frequency. This is a characteristic of a forged crank and cannot be eliminated by balancing or any other machine operation. Because of their amorphous grain structure cast cranks have no resonant frequency---a very important feature! I'm not saying that cast cranks are better than forged, they each have their strengths and weaknesses, but cast cranks aren't as bad as people think.

As a matter of fact, I have never broken a cast crank in over 30 years of racing and I have broken over 20 forged cranks. (Of course I have carefully chosen when and where to use cast cranks--like dirt track racing where you can't hook the tires up well, but you need excellent vibration resistance.) Use a forged crank if you are going to do high RPM clutch drops regularly with a car that really hooks up. I know that Chevrolet's warranty on cranks backs up what I have stated here with respect to crank cracking; (i.e. on a percentage basis, forged cranks crack more frequently than cast). I have tested twin turbo'd big blocks with cast cranks running 15# of boost through dual water to air intercoolers making 900HP and 1000lb-ft of torque pulling water skiers at over 90mph in the Catalina island water ski races and we never had a crank failure. It's all in how you put the package together and determining what you need. A forged crank won't get you one hp. Unless you are stroking your engine or going to be really abusing the entire driveline, don't waste your money on a forged crank.

 

Wow I learned about 6 things today!!! I better stop be for the old head . j/k Thanks for all the info man. I guess alot of people spend money on parts they don't really need when building performance street motors.