Xr265hr-15 with ls6 spring.
Xr265hr-15 with ls6 spring. I got a 04 a4 gto. It has intake, pacesetter LT, catless mids, 05-06 cat back. I also have, but have not installed yet. A 2500 stall and plan to spray a 75 shot. But my question is can I use the xr265hr-15 in the car with the ls6 springs. The specs on the cam are 212-218 .558-.563 with 115 lsa. Keep in mind also this is my wifes car. And it usally gets driven like a g-mah owns it. It might get a run or 2 a month. also the car will retain the stock rev limiter, and shift points.
I think the ls6 springs will do, but why not opt for some beehve 918's or the like? They would for sure be a huge improvement over a stock spring and give you peace of mind.
i will be putting a set of spring and hardned push rods in after xmas and all that is over with. but i got to pull the radiator this week to replace it, and figured while im already half way to getting the cam out. why not go ahead and slap it in there.
im not pulling the whole front of the car apart twice. i have got to do the radiator this week so she can drive the car to work. i can always swap out the springs and pushrods way easyer then pulling the rad, condensor,bumper, etc to get the cam out. plus i dont want to spend the extra $100+ on fluids and freon twice. from the research i have done the ls6 spring should be fine aslong as i dont rev it past 6200. when i get the extra money ill throw some springs in it. and put a good dyno tune on it. but i really think ill be ok for the time being.
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Joined: Feb 2009
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put the springs and push rods in now ,or don't rev it pass 3500 rpm.the ls6 springs are designed for different cam lobe ramps then the cam you want to install.never cut corners with a engine build ,especially with valve train parts.
theres a whole thread on perfomance truck about some one using that cam on yellow springs with a boosted motor. i mean i know its getting close on the ls6 springs but i dont think the things going to let loose as soon as i hit 4K lol but i could be wrong. i think im going to try my luck thow. this thing dosnt get beat on all that hard.
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so just a quick update. just did my 1st oil change since the cam. motor is runing strong the ls6 springs are holding up great. i have beat on it several times with 0 problems. drove it to daytona for turky rod run. and have been driving it to work daily. it didnt blow up as soon as i hit 3k rpms lol and im sure it will be fine. i still plan to upgrade the spring and pushrods. but for the time being they are fine.
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Launching!
Joined: Jun 2010
Posts: 255
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From: Alberta, Canada
I've ran those lobes in a 4.8 with comp pushrods and yellow springs. Didn't have a problem. They were actually the 216 and 220 duration lobes. Took it past 7000 rpms every time I drove it with no sign that they were not up to the task.
TECH Senior Member
Joined: Feb 2009
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the engine won't blow up ,but you mite experience valve float which will effect power.test the valve springs to see if they can produce proper spring pressure.why spin a motor past peak hp of a mild cam ?frictional hp loss will get greater as rpms go up.I would not trust stock GM trunnion bearings at high rpms,or the stock gm rod bolts.
Launching!
Joined: Jun 2010
Posts: 255
Likes: 1
From: Alberta, Canada
the engine won't blow up ,but you mite experience valve float which will effect power.test the valve springs to see if they can produce proper spring pressure.why spin a motor past peak hp of a mild cam ?frictional hp loss will get greater as rpms go up.I would not trust stock GM trunnion bearings at high rpms,or the stock gm rod bolts.
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Joined: Nov 2004
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From: Tampa FL
This is the truth right here. The yellow GM springs are good to .550 lift on a fairly mild lobe. Even though the lift isn't much over .550 the ramp rates on that cams lobes will cause the spring to fatigue over time. I would replace them with Comp 918 or equivalent springs as zoo as I could if I were you.
