Thinking about finally doing a cam.. What pushrods for the LS3?
03-15-2009, 06:41 PM
#1
Thinking about finally doing a cam.. What pushrods for the LS3?
Anyone know what length pushrods I need for the LS3? 7.4? or 7.425?
I'm been bored today, so I've been looking at a couple cams. I've also read about the LS3 TC failures... Looks like I will be upgrading the TC...
I'm been bored today, so I've been looking at a couple cams. I've also read about the LS3 TC failures... Looks like I will be upgrading the TC...
03-16-2009, 12:03 AM
#2
Safety Car
Member Since: Jan 2008
Location: Middle of No where AK
Posts: 4,711
Likes: 0
Received 2 Likes
on
2 Posts
Depends on your head size. I think the factory ones are 7.4. You may also want to get a push rod checker from comp cams for about 16 bucks. Could save you some heartache.
03-16-2009, 03:58 AM
#3
Tech Contributor
If you go with a cam 224 intake or larger, the base circle is .060" smaller and hence the pushords would optimumly need to be .030" longer. If heads are milled .030", the pushrod length goes back to the stock 7.4" but you are asking solely about a cam swap so its 7.430" or the popular stocked size of 7.425" is fine to maintain the stock preload on the lifters.
03-16-2009, 07:14 AM
#4
If you go with a cam 224 intake or larger, the base circle is .060" smaller and hence the pushords would optimumly need to be .030" longer. If heads are milled .030", the pushrod length goes back to the stock 7.4" but you are asking solely about a cam swap so its 7.430" or the popular stocked size of 7.425" is fine to maintain the stock preload on the lifters.
03-16-2009, 09:42 AM
#5
Drifting
Member Since: Feb 2007
Location: Alpharetta Georgia
Posts: 1,843
Likes: 0
Received 12 Likes
on
8 Posts
If you go with a cam 224 intake or larger, the base circle is .060" smaller and hence the pushords would optimumly need to be .030" longer. If heads are milled .030", the pushrod length goes back to the stock 7.4" but you are asking solely about a cam swap so its 7.430" or the popular stocked size of 7.425" is fine to maintain the stock preload on the lifters.
Last edited by 1.8t; 03-16-2009 at 10:03 AM.
03-16-2009, 06:41 PM
#7
Le Mans Master<br><img src="/forums/images/ranks/5k-6k.gif" border="0">
Member Since: May 2007
Posts: 5,399
Likes: 0
Received 0 Likes
on
0 Posts
St. Jude Donor '08-'09
What would happen if a longer than needed pushrod were used? If the cam manufacturer wanted .020 preload and a longer rod was used to bring the preload up to .100, would there be any kind of problem?
03-16-2009, 06:57 PM
#8
Spin, my cam is a 231/243 .617/.623 on Comp LSL lobes and I measured during my rebuild and came to a pushrod length of 7.400 with .100 worth of lifter preload with my adjustable pushrod from Comp. Zero lash was right at 7.300 on both intake and exhaust. Yes, the procedure of measuring was performed correctly. Any ideas regarding this discrepancy versus your math?
Are your heads stock or milled? Block stock or decked?
03-17-2009, 03:06 AM
#10
Race Director
Member Since: Dec 2006
Location: Fort Worth, Texas
Posts: 11,120
Received 2,054 Likes
on
1,306 Posts
what cams are ya contemplating between and who's gonna do the install?
03-17-2009, 02:22 PM
#11
I'll probably go with one of the new comp cams that was designed for the rectangular port. I want one that is well matched for the new Fast 102mm manifold.
Speedtek has done all my work in the past and I've never had any problems. I would have Josh install it, but he charges more than Speedtek last I checked....
Speedtek has done all my work in the past and I've never had any problems. I would have Josh install it, but he charges more than Speedtek last I checked....
Last edited by xstang; 03-17-2009 at 02:30 PM.
03-18-2009, 09:12 AM
#12
Burning Brakes
If you go with a cam 224 intake or larger, the base circle is .060" smaller and hence the pushords would optimumly need to be .030" longer. If heads are milled .030", the pushrod length goes back to the stock 7.4" but you are asking solely about a cam swap so its 7.430" or the popular stocked size of 7.425" is fine to maintain the stock preload on the lifters.
-Brandon
03-19-2009, 01:58 AM
#13
Race Director
Member Since: Dec 2006
Location: Fort Worth, Texas
Posts: 11,120
Received 2,054 Likes
on
1,306 Posts
I'll probably go with one of the new comp cams that was designed for the rectangular port. I want one that is well matched for the new Fast 102mm manifold.
Speedtek has done all my work in the past and I've never had any problems. I would have Josh install it, but he charges more than Speedtek last I checked....
Speedtek has done all my work in the past and I've never had any problems. I would have Josh install it, but he charges more than Speedtek last I checked....
03-19-2009, 08:28 AM
#14
03-19-2009, 08:38 AM
#15
I ran a 215/232 117 LSA for a long time on my LS2 and loved it!
Last edited by xstang; 03-20-2009 at 07:55 AM.
03-20-2009, 05:32 AM
#16
Race Director
Member Since: Dec 2006
Location: Fort Worth, Texas
Posts: 11,120
Received 2,054 Likes
on
1,306 Posts
won't that cam require fly cutting?
03-20-2009, 07:57 AM
#17
It does, because of the better dcr and the smaller intake duration keeps port velocity up w/ the larger intake runners of the ported heads...it put down 25more rwhp and 17more rwtq(part of the gain has to be attributed to the udp tho) it gained from 3000rpm up and the power curve is so flat...it holds 350ftlbs to 6k and from there to 6800 the hp is pretty much flat...made some shake down runs at kennedale last night and it ran a 7.3@96 (1.69) 75* temp, weird thing is I think my et streets are spinning on the rims as I can hear noise from rear only under full throttle on good surface, need to mark them and find out...
won't that cam require fly cutting?
won't that cam require fly cutting?
You are moving!!!! I can't wait to see what my setup will do with the restall, cam and Fast 102...
