TFS 245 vs. TFS 260
03-15-2019, 06:25 PM
#181
Originally Posted by Smokey B
You'd need to get with a porter and discuss chambers and a 300 shot of drugs. BES or C. Frank off the top of my head and a Mast,all pro, now the big spring brodix head my fav 4 cost. If you know of Dennis Wheat GREAT head porter and person. CID 4500 intake with a accufab 5500 or 6500 Tb port matched top end.
03-15-2019, 06:31 PM
#182
There around 1k for head port work. Buy your own parts & heads. 1 of The best @ 45 min away? Your crazy... Close mouth Won't get Feed! It's listed on there site as a Brodix or All Pro head package. You supply dirt cheap brodix heads @ around 1400.oo then Cnc 1k to 1500. Parts needed for valve train.
Last edited by Smokey B; 03-15-2019 at 06:40 PM.
03-15-2019, 08:40 PM
#185
Once i compared valve lengths i kinda would just do somethings different as far as heads and which casting. Spring pads and porting with thinner casting. With some a larger spring pad isn't a option.
03-15-2019, 11:39 PM
#186
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Originally Posted by spanks13
Valves are Ti intake and stainless exhaust.
Predictability of the power delivery is really what I'm looking for. I'd like as flat of a torque curve as possible that carries as high as possible. Smooth and consistent power up to redline, and something that will pull 5th gear to 7800rpm @ 200 mph without running out of steam. It is important to me for the engine to still be maintaining or building power at maximum rpm.
The only thing that keeps me up at night is if I'm going to overshoot the horsepower peak on accident and wind up with an engine that wants to peak at 8000 rpm. Second worry is that it won't have enough ***** at ~5600 rpm to pull away from the gear changes.
Predictability of the power delivery is really what I'm looking for. I'd like as flat of a torque curve as possible that carries as high as possible. Smooth and consistent power up to redline, and something that will pull 5th gear to 7800rpm @ 200 mph without running out of steam. It is important to me for the engine to still be maintaining or building power at maximum rpm.
The only thing that keeps me up at night is if I'm going to overshoot the horsepower peak on accident and wind up with an engine that wants to peak at 8000 rpm. Second worry is that it won't have enough ***** at ~5600 rpm to pull away from the gear changes.
03-16-2019, 05:35 PM
#187
Thanks both of you. I like the input.
Darth, I think you’re right about IVC ~56. I had pushed it to 60 thinking it would help with when it’s run on 91 (e85 for racing, but will detune it to be drivable on 91), and also would keep the midrange from coming in too hard. I think I overshot it though, and that’s really what was making me worry it wouldn’t pull hard enough from 5500. I think 60* IVC I’d be having to push my shifts to 8200. Now, a 6000 stall auto likes in my drag car...that’d be a different story.
I also am starting to like the 114 LSA vs 116. 114 is already a very wide LSA given these duration numbers. A race engine with a big single plane would tend to be more in the 108-110 range. 116 might be overcompensating.
That said, I do think I want to keep a longer exhaust duration - I believe that’ll help me bleed off some torque in the midrange that I really don’t want, but as the revs climb it’ll actually be more appropriate and help it carry past peak.
With the lobes I’m looking at, 258/276 114+4
IVO is 16.0 ° BTDC ( - indicates ATDC)
IVC is 56.0 ° ABDC
EVO is 73.0 ° BBDC
EVC is 17.0 ° ATDC ( - indicates BTDC)
Overlap is 33 °
Darth, I think you’re right about IVC ~56. I had pushed it to 60 thinking it would help with when it’s run on 91 (e85 for racing, but will detune it to be drivable on 91), and also would keep the midrange from coming in too hard. I think I overshot it though, and that’s really what was making me worry it wouldn’t pull hard enough from 5500. I think 60* IVC I’d be having to push my shifts to 8200. Now, a 6000 stall auto likes in my drag car...that’d be a different story.
I also am starting to like the 114 LSA vs 116. 114 is already a very wide LSA given these duration numbers. A race engine with a big single plane would tend to be more in the 108-110 range. 116 might be overcompensating.
That said, I do think I want to keep a longer exhaust duration - I believe that’ll help me bleed off some torque in the midrange that I really don’t want, but as the revs climb it’ll actually be more appropriate and help it carry past peak.
With the lobes I’m looking at, 258/276 114+4
IVO is 16.0 ° BTDC ( - indicates ATDC)
IVC is 56.0 ° ABDC
EVO is 73.0 ° BBDC
EVC is 17.0 ° ATDC ( - indicates BTDC)
Overlap is 33 °
Last edited by spanks13; 03-16-2019 at 07:07 PM.
03-16-2019, 07:19 PM
#188
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I dont think that is a bad spec at all. I tend to set EVO based on compression. So if you take EVO to 73, def want to be closer to 12.5 compression.
FWIW I run a 114 LSA also. Does great but I also run 12.3 compression. Compression helps it work better with those late IVC and early EVO
FWIW I run a 114 LSA also. Does great but I also run 12.3 compression. Compression helps it work better with those late IVC and early EVO
03-17-2019, 06:56 AM
#190
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Lol your cam will like 11.5 a LOT
03-18-2019, 12:36 AM
#191
My 427 does not miss any low end tq from the sniper intake. Car drivers great yet fried the tires in 2nd from a 60 roll.
295/45/17 mt drag radials.
the 275/60mt et street pro hold from a roll and it's gone. No soft spot in tq.
that was with a hurt vearing, version 2.0 coming back soon
295/45/17 mt drag radials.
the 275/60mt et street pro hold from a roll and it's gone. No soft spot in tq.
that was with a hurt vearing, version 2.0 coming back soon
03-18-2019, 05:37 AM
#192
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Originally Posted by AINT SKEERED
My 427 does not miss any low end tq from the sniper intake. Car drivers great yet fried the tires in 2nd from a 60 roll.
295/45/17 mt drag radials.
the 275/60mt et street pro hold from a roll and it's gone. No soft spot in tq.
that was with a hurt vearing, version 2.0 coming back soon
295/45/17 mt drag radials.
the 275/60mt et street pro hold from a roll and it's gone. No soft spot in tq.
that was with a hurt vearing, version 2.0 coming back soon
03-18-2019, 06:23 AM
#194
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Originally Posted by Floorman279
yea but with that mentality, couldn't you just say meh 500 rwhp is enough? well yea it is but we still build to 600 and 700......i look at low and mid range power the same way......500 tq would be enough, by why not 550......
I would be much more concerned about losing midrange in a smaller engine. Definitely understand the too much is almost enough principle.
03-18-2019, 04:43 PM
#197
That is a big distinction. It is one thing to say - I want to build to maximize midrange torque. An entirely different thing to say - I am scared to lose too much low end torque. Especially on a big ehugngine. Gained 100 lbs of torque peak to peak going to a bigger engine from the 346.
I would be much more concerned about losing midrange in a smaller engine. Definitely understand the too much is almost enough principle.
I would be much more concerned about losing midrange in a smaller engine. Definitely understand the too much is almost enough principle.
now in the future, I might get a c6 and do a 4.125 bore, 3.622 stroke sheet metal with an 8000 rpm shift, or just easy way out procharger.
03-18-2019, 06:52 PM
#198
Got a message from Bob @ all pro, heads range from 2000 to 2200 for as cast heads Ls7 or C5r port.
Greg Good now has a cnc machine so return times should be quicker
CID Ls 7 heads cnc bare start @ 2800
Greg Good now has a cnc machine so return times should be quicker
CID Ls 7 heads cnc bare start @ 2800
03-18-2019, 07:17 PM
#199
i am a little biased, I mean my motor isn't running yet, but I know the shortcomings my ls1 had with the giant cam, so trying to avoid those. I know it's goona naturally make more torque, but I also like the idea personally for me to keep the red line around 7450 for a 7400 shift, was built by a reliable source but I feel safer for longevity about keeping the rpms under 7500, since it wasn't specifically built for anything higher. So it only makes sense for me to build the low end rather than the high end, since to capitalize on the high end I should really be shifting after 7500, since peak would probably be 72-7300. I mean all the good guyss talk about shifting at least 500 past peak.
now in the future, I might get a c6 and do a 4.125 bore, 3.622 stroke sheet metal with an 8000 rpm shift, or just easy way out procharger.
now in the future, I might get a c6 and do a 4.125 bore, 3.622 stroke sheet metal with an 8000 rpm shift, or just easy way out procharger.
mine peaked at 6800 and flat lined
