Friday25 Posted November 13, 2012 Report Share Posted November 13, 2012 So I've recently been contemplating putting a cam in when I get home in Feb., but I am concerned with how strong the stock bottom end is. No existing problems at all, but I'm already at approx. 550hp on the motor with the current setup. I really want to throw a cam in it but I don't want it to be unreliable either. Any info would be great. Thanks. Quote Link to comment Share on other sites More sharing options...
silverado777 Posted November 13, 2012 Report Share Posted November 13, 2012 (edited) How did you come up with your HP #? Stock bottom end should be good to about 600hp but I have seen them break at 400 and have seen them with stand 1000. Truckin just had a TT 5.3l with a stock bottom end pushing 26psi of boost and hit 1300HP. When it failed on the last run the only thing that was wrong was a broken rocker arm. Edited November 13, 2012 by Silverado777 (see edit history) Quote Link to comment Share on other sites More sharing options...
idahoBLKss Posted November 13, 2012 Report Share Posted November 13, 2012 bottom end is plenty strong.if you mess up the bottom end your doing it wrong ... lol . but your tune/tuner has a BIG roll in that . Quote Link to comment Share on other sites More sharing options...
Blown 346 Posted November 13, 2012 Report Share Posted November 13, 2012 (edited) The bottom ends on the LS based motors are strong. My vette made 716 RWHP and over 800 at the crank with stock internals with no problems. My camaro makes a little over 700 at the crank since 2002 with no problems. I would upgrade the rod bolts to ARP for safety measure. Edited November 13, 2012 by Blown 346 (see edit history) Quote Link to comment Share on other sites More sharing options...
2bfast Posted November 13, 2012 Report Share Posted November 13, 2012 How did you come up with your HP #? my thoughts exactly Unsure why you are worried about the bottom end by just adding a cam? Unless your shift points are high now and the cam you want will raise the desired shift point to be in power band. Explain more please Quote Link to comment Share on other sites More sharing options...
shawnss Posted November 13, 2012 Report Share Posted November 13, 2012 How did you come up with your HP #? Stock bottom end should be good to about 600hp but I have seen them break at 400 and have seen them with stand 1000. Truckin just had a TT 5.3l with a stock bottom end pushing 26psi of boost and hit 1300HP. When it failed on the last run the only thing that was wrong was a broken rocker arm. not trying to prove you wrong or anything like that. I was reading the same deal on the high HP 5.3 did you see at the end of the story were it ended up being a 4.8L. crazy. Quote Link to comment Share on other sites More sharing options...
silverado777 Posted November 13, 2012 Report Share Posted November 13, 2012 not trying to prove you wrong or anything like that. I was reading the same deal on the high HP 5.3 did you see at the end of the story were it ended up being a 4.8L. crazy. No I didn't! I only had a chance to glance over the good stuff and didn't read it in detail. Either way thats crazy. Those engines love boost. I know they ended up swapping the heads to lower the compression. Quote Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted November 14, 2012 Report Share Posted November 14, 2012 bottom end is plenty strong.if you mess up the bottom end your doing it wrong ... lol . but your tune/tuner has a BIG roll in that . word for word.... I'm running 504 at the wheels and shifting at 7200 on stock rod bolts and i dyno to around 7300. I have hit 8030 by a mistake...twice. Rod bolts are tested with rpm not hp, and a magnacharged motor shouldn't have to test them. Quote Link to comment Share on other sites More sharing options...
Fireman31 Posted November 14, 2012 Report Share Posted November 14, 2012 Add the cam, make sure to do pushrods and valve springs too. Many have done it in conjunction with Radix kits, you should be fine. The stock lower half has been strong enough to hold up to repeated mid 11 second passes in a few trucks here...... Quote Link to comment Share on other sites More sharing options...
Friday25 Posted November 14, 2012 Author Report Share Posted November 14, 2012 I came up with the Hp number by my Rwhp and figuring an 18% loss. I'm only worried about the added Hp being too much for the bottom end, thats about all, and I had Blackbear do the tune I have now so I'll have them do it again after the swap. Was already planning on changing the springs, so if the pushrods are highly recommended then I can drop those in too. Are the stock ones fairly week. Quote Link to comment Share on other sites More sharing options...
Blown 346 Posted November 14, 2012 Report Share Posted November 14, 2012 Anytime you do a cam swap it is highly recommended that you replace the pushrods. Yes the stock ones cant handle the lift and pressure and will bend or break causing more problems you dont want to deal with. Adding a cam wont hurt the motor. I have built 4 or 5 LS motors and they have all been stock bottom ends and make anywhere from 600 to over 700 RWHP and I have never lost one yet... The bottom ends on these engines arent given enough credit. The cranks can handle 800 all day.... Quote Link to comment Share on other sites More sharing options...
Friday25 Posted November 14, 2012 Author Report Share Posted November 14, 2012 Thanks for the info man, I've never worked with the LS motors, just the old small block for the most part. I did read a thread a while back about the lifters staying in place when you pull the cam...does that sound right? Also I'm trying to decide which cam to use, I'm looking at the Lingenfelter gt2-3 and the gt9. Has anyone used either of thse cams? Quote Link to comment Share on other sites More sharing options...
silverado777 Posted November 14, 2012 Report Share Posted November 14, 2012 Why don't you use a blower cam since you have a blower Quote Link to comment Share on other sites More sharing options...
Blown 346 Posted November 14, 2012 Report Share Posted November 14, 2012 The lifters will go into "cups" when you spin the cam several times by hand. Use a blower cam with little overlap to get the most power out of it. To get the best cam you need to talk to a builder or someone who specializes in motor setups. Your other supporting mods will have a huge factor in what cam you go with as well as any future plans. Quote Link to comment Share on other sites More sharing options...
detjoe Posted November 14, 2012 Report Share Posted November 14, 2012 the hotrod article is filled with dyno tricks...I believe the pulls started way up in the RPM's and when they tried to do a full pull it broke. Go for it. but be warned your radix is already small so as you make other parts of your dirvetrain better the bottle kneck is going to be the heat soak, cause by spinning it(blower) to get the air your motor needs. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.