chevyss2008

Im in the process of swapping out my LS1 in my WS6 with a LS3....I have the TFS 255 GenX heads for it and trying to decide between the TFS cam that comes with those heads in their LS3 top end kit or the new LS3 TSP Stage II cam. The TFS cam is TFS-32603001 230/238 .615 on 113 and the TSP cam is #25-TSP229244 229/244 629/615 on 112...TFS dyno is 580 with the heads/cam combo and TSP is 568hp on stock heads and block...Specs on the heads from TFS webpage says .625 is max lift, so that concerns me on the TSP cam. But TSP says there are no PTV issues with their cam on stock heads, so in theory it should be fine with the 255 heads? My main 2 concerns are PTV and the max lift stated for those heads...Hoping to get more input and info from those that know more than me on those heads and 2 cams...

G Atsma

PTV has more to do with duration and overlap and very little to do with lift. Max lift is only achieved when the piston is well down the cylinder.

chevyss2008

I understand that part, that's why I had asked them in 2 diff instances, or at least thought I did. The TSP has more duration and that was my concern with that cam...Sorry if I didn't ask it that way

chevyss2008

Also running LS3 1.7 rockers and trunion upgrade...

chevyss2008

Forgot to mention, this is an A4 car...Performabuilt Level 2 with FTI 9.5 Billet 3600 convertor

99 Black Bird T/A

iTrader: (4)

I would contact Trick Flow or the vendor that you purchased the heads from and ask if the springs need to be replaced or shimmed differently for the TSP cam with .629 lift. They may tell you that with the typical hydraulic lifter bleed down, push rod deflection etc it will be OK as is or a recipe for problems as is unless certain changes are made.

If over .625 causes coil bind then .629 will probably break the current springs at some point.

You're probably already aware that over. 600 lift starts side loading the valve guides with a stock LS1/LS3 rocker. A lot of folks sort of view .625 lift as an acceptable degree of side loading for a street motor that needs to live 50,000-60,000 miles to maybe 80,000 miles or so before the valve guides are worn out. There is some variation depending on how centered the rocker wipe pattern is on the valve tip. At .650 lift the about of stress is increased and they wear worse. Even a .581 lift cam will side load the stock rockers some. I ran the 224 .581 lift XER cam for 125,000+ miles and rocker tips & valve tips show some wear. Wipe pattern was good the rockers were shimmed to get best set up possible by a good friend. FWIW - .625 lift is as far as I'm comfortable pushing stock rockers. Many others are comfortable with .626 to .650 lift in their applications.

Seems like for this set up it would be critical to measure measure pushrod length and be on the money. Likewise, if using the TSP cam just to play it very safe, I would have it put on a cam doctor so you know exactly what the lift will be. Cams are usually very close to the advertised spec but there are variances in manufacturing - even the best process and quality control. My old 224/224 .581/.581 lift XER cam was actually a 224.8 duration cam with .582 lift. Likewise, I have a GT2-3 that is normally a little 207/220 .570/.578 cam that measured 208/221 .570/.578 lift and so on.

My 99 TA's 416 has a Reher - Morrison 237 / 245 .625 lift 114 cam. The 91 RS's LS1 383 an obsolete MMS 229/229 v2.1 .578 114 grind from 2001.


BTW - while it would be extremely unwise/foolish on a street engine to run .000 intake clearance, Had friends that do on that on race engines - because the block & heads up and grow, push rods deflect and hydraulic lifter bleed all add up to a bit more clearance in a warm engine.

FWIW - The above info is based on my experience with LS engines and the info and judgements passed on by the folks that helped me with my LS engines over the years. Like any Internet info be sure to double check and confirm before taking any thing as an absolute.

Good luck with your engine build! The Trick Flow heads are sweet!

Tuskyz28

I'm running a 229/244 cam from BTR with stock LS3 heads on top of a sbe LS2. Cam pulls really strong especially past 4000 rpm.

Jimbo1367

Since you are replacing the cam, pushrods and have concern on rockers, it might be worth while to check in on some TSP OEM type roller tip rockers.

big hammer

big hammer

chevyss2008

I went ahead and ordered the TFS Cam. The GenX heads do have double springs from factory. I have new BTR Pushrods, same spec as the TFS rods..7.75...080 5/16...Also have the trunion upgrade.

Jimbo1367

Make sure you dynotune it and share your results.

chevyss2008

I will be making the 8 hour round trip for Pat G to tune it, but not really big into dyno numbers....To me its just a tool used for tuning.

NAVYBLUE210

Good Decision on the Cam choice IMO. TFS LS3 Heads do not need the huge exhaust split that the OE LS3 Heads
do, due to their much better exhaust flow performance & E/I ratio. A +6-10* Split is the NA sweet spot for a NA
Street/Strip LS3 aftermarket (MMS,AFR,TFS,MAST,SPS or well ported stockers) IMO
up to >7000 RPM with good 1 7/8" LTs & a true dual exhaust.

My suggestion would be to have the stock IM ported, Very little if any benefit VS FAST with standard runners.
Cam size is borderline wether it would help with Mid Length Runners AND... your valve train is not
optimised to spin the 7500 RPM needed to take advantage of mid length runners.

I think you will be very happy with your results & DRIVABILITY
Great Decision on your tuner Obviously as well.

chevyss2008

Thanks...Im running Speed Engineering 1 7/8 Headers and their true dual (no cats etc) exhaust set up. Have ready several test where the stock LS3 intake was supporting over 800, so I think I should be fine there. Im prob going to have my shift points set at 6500..I just couldn't see the extra $800+ for a Fast set up (only like 9hp diff), I rather spend the $ saved on other mods such as the 12 bolt that's going in later. Pat has tuned twice for me, always happy with his work and def worth the drive.

KW Baraka

iTrader: (7)

Neither of those cams will have PTV clearance with the Trick Flow heads.

KW