Comp 918 Spring Poll
Re: Comp 918 Spring Poll The way I see it any spring can break <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> I've run 918's without problems,even the bad batch.I do not put too many miles on my car,but I do hammer it everytime I'm out.A big thing to do is make sure the engine is fully warmed up(oil) before revving it up high.A cold spring could break very fast. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
TECH Resident
Joined: Nov 2001
Posts: 766
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From: Houston
Re: Comp 918 Spring Poll I just broke a 918 under normal driving. 2-2500rpm <img border="0" title="" alt="[Sad]" src="gr_sad.gif" /> I shift the car at 6400 when I run it hard. Spring broke in 2 places. Lift is .584 on the cam. No stripe on the spring that I can see.
AJ
AJ
Thread Starter
Staging Lane
Joined: Jan 2002
Posts: 54
Likes: 0
From: Houston
Re: Comp 918 Spring Poll Over revving may have caused additional harmonics in the spring which may have led to the failure; hard to say. To measure the installed height, it requires the spring to be removed. The retainer is then re-installed and the space occupied by the spring is measured with a telescoping gage, and read by a micrometer. There are also micrometer style gages that fit within the spring pocket. Just adjust them out until no more space exists, then read the installed height on the micrometer dial.
Paul J.
Paul J.
Re: Comp 918 Spring Poll I could check the spring height. I'll probably buy the tool if it's cheap and I can find it. What's it called and where can I get it?
All of these springs have less than $1k miles on them. I have a TH350 with no speedo hook-up so I don't know the mileage. I actually think it's about 500 miles.
Am I just crazy to rev it all the way to 6800? Is that more than the 918's are rated for? It's seen 7k by accident(rev limiter) before as well.
<small>[ December 27, 2002, 01:07 PM: Message edited by: 4mulaJoe ]</small>
All of these springs have less than $1k miles on them. I have a TH350 with no speedo hook-up so I don't know the mileage. I actually think it's about 500 miles.
Am I just crazy to rev it all the way to 6800? Is that more than the 918's are rated for? It's seen 7k by accident(rev limiter) before as well.
<small>[ December 27, 2002, 01:07 PM: Message edited by: 4mulaJoe ]</small>
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Teching In
Joined: Jan 2003
Posts: 7
Likes: 0
From: Irving, Texas
Re: Comp 918 Spring Poll As luck would have it I also had a 918 comp spring break on Wednesday, cam is a tr224. It did drop the valve into the cylinder, unfortunately this is as far as my mechanical ability goes so it will have to go to the repair shop. Spoke to Speedtek in Dallas and they will warranty the springs however the rest will have to come from my pocket. <img border="0" title="" alt="[Mad]" src="gr_images/icons/mad.gif" /> My car dynoed at 385 hp 377 tq on bottle it did 518 hp and 577 tq car had 4.10's at the time and now I am running the stock 3.42's
TECH Enthusiast
Joined: Nov 2002
Posts: 593
Likes: 1
From: Chicago Heights, IL
Re: Comp 918 Spring Poll This may be a novice question, but how do you know when you break a spring? Does the car exhibit different behavior if you break an exhaust valve spring or an intake valve spring? What are the symptoms?
Re: Comp 918 Spring Poll </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Constrictor 98TA:
<strong> This may be a novice question, but how do you know when you break a spring? Does the car exhibit different behavior if you break an exhaust valve spring or an intake valve spring? What are the symptoms? </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">You can pretty much tell not all 8 cylinders are firing right.
<strong> This may be a novice question, but how do you know when you break a spring? Does the car exhibit different behavior if you break an exhaust valve spring or an intake valve spring? What are the symptoms? </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">You can pretty much tell not all 8 cylinders are firing right.
Re: Comp 918 Spring Poll </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Firehawk 01:
<strong> As luck would have it I also had a 918 comp spring break on Wednesday, cam is a tr224. It did drop the valve into the cylinder, unfortunately this is as far as my mechanical ability goes so it will have to go to the repair shop. Spoke to Speedtek in Dallas and they will warranty the springs however the rest will have to come from my pocket. <img border="0" title="" alt="[Mad]" src="gr_images/icons/mad.gif" /> My car dynoed at 385 hp 377 tq on bottle it did 518 hp and 577 tq car had 4.10's at the time and now I am running the stock 3.42's </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Which batch was this? When did you purchase yours? Were you spraying at the time it broke?
Just curious cause I'm throwing in a set of 918's next week.
<strong> As luck would have it I also had a 918 comp spring break on Wednesday, cam is a tr224. It did drop the valve into the cylinder, unfortunately this is as far as my mechanical ability goes so it will have to go to the repair shop. Spoke to Speedtek in Dallas and they will warranty the springs however the rest will have to come from my pocket. <img border="0" title="" alt="[Mad]" src="gr_images/icons/mad.gif" /> My car dynoed at 385 hp 377 tq on bottle it did 518 hp and 577 tq car had 4.10's at the time and now I am running the stock 3.42's </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Which batch was this? When did you purchase yours? Were you spraying at the time it broke?
Just curious cause I'm throwing in a set of 918's next week.
Re: Comp 918 Spring Poll I had one from May of 2002 fatigue on me~ 8kmiles.
I have run the Car hard, and shift ~ 6800, limiter is @ 7200. Plus, its a big cam.
IT didnt actually break, but it became weak enough to let one valve get tagged. After inspection, the spring is ~ 200 thou smaller top-bottom than all other 15. It happens. And Its going to happen again. Its just something that we have to take into consideration with our hotrods.
I broke 2 941s previously, and Im sure that Ill break more. Big cams, high RPMs, and lots of miles take their toll on springs.
Im now going to a REV double <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Take care
Louis
I have run the Car hard, and shift ~ 6800, limiter is @ 7200. Plus, its a big cam.
IT didnt actually break, but it became weak enough to let one valve get tagged. After inspection, the spring is ~ 200 thou smaller top-bottom than all other 15. It happens. And Its going to happen again. Its just something that we have to take into consideration with our hotrods.
I broke 2 941s previously, and Im sure that Ill break more. Big cams, high RPMs, and lots of miles take their toll on springs.
Im now going to a REV double <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Take care
Louis
Re: Comp 918 Spring Poll I also scratched the 918 plan. My head machine shop also recommended the REV dual and I'm going with those, at least I wont drop a valve if one of those breaks.
TECH Addict
Joined: Dec 2001
Posts: 2,298
Likes: 2
From: new england
Re: Comp 918 Spring Poll I run #918 with .585" cam to 6500 rpm many times.I drive car daily, springs have over
13,000 miles and several backshifts with no valve control loss issues! Im still a fan of these springs.
13,000 miles and several backshifts with no valve control loss issues! Im still a fan of these springs.
Thread Starter
Staging Lane
Joined: Jan 2002
Posts: 54
Likes: 0
From: Houston
Re: Comp 918 Spring Poll Wow, keep the reply's coming. I will be beginning my 918 experience today with a set of ported LS6 heads and Comp 220 .564 lift cam. They are the latest "Blue Stripe" variation. I will keep everyone posted.
Paul J.
Paul J.
