DIY 241 heads w/small EPS only
#1
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Picked up my first vette just b4 Christmas an Anniversary Red 2003..M6
with only 15 thou on it. Absolutely stock except a Corsa X with Pacecar
axle-back. I didn't dyno it but suspect from others on here maybe would have
done about 310-315rwhp. I picked up an ls2 chain and oil-pump O-ring from
TSP and an EPS 218-.595/ 226-.598 117+3deg. I'm reusing the oil pump and
rockers since such low mileage. Special thanx to RED98C5 for the new LS6
valves shipped @185..I also went w/ Lunati GOLD dual kit for $225(good deal)
Since its still in the 30s and 40s here in WIS I'm in no extreme hurry to slap
this thing back together as this is my first LS modding(wanna do it right)
When it's all together I'll be taking it to Speed Inc. in Shaumburg, Ill for the
tune and chassis dyno. Since I gasket matched the EX. manifolds I guess
I'l be happy with anything over 360 to the ground. While waiting for the cam
I couldn't resist pulling the 241s and really wish I had the coin to send to AI
but ultimately decided to mess with them myself after reading some of the
success stories on here.
I'd first like to state that I've ported at least a hundred sets of heads over
25 years of engine building but never had any of them flowed and this is my
first screwing with an LS head. I decided to keep it to a minimum as I would
be happy with any improvement and didn't want to F#@K them up.
I didn't flow them B4 but decided to use Advanced Inductions stock #s
as my comparison:........................Mine flowed: no pipe...... ex. w/pipe
.100...................66-55.............................65-54..................54
.200..................139-101.5.......................135-97.5..............101
.300..................193-136..........................196-130...............137
.400................215.5-160..........................234-168...............180
.500..................226-171.......................... 240-191...............198
.550..................231-176...........................241-197...............215
.600..................233-180...........................244-201...............221
EX w/o pipe 3.9 bore fixture
I guess I'll take the minimal improvement based on my total time invested
of less than 4 hours. I also left the factory valve job and lapped the new ls6
valves. The time breakdown is just shy of 1.5hrs on the intakes with carbide
cutting the rocker boss(leaving it rough) and 80 grit blending the bowls. I
didn't touch the swirl ramp in the bowl or the guide boss.
Also just under 2.5hrs. on the exhaust with blending the bowls, streamlining
the guides and gasket matching the roof and sides(left the floor alone)
Side note: the intake spiked 245.5 cfm @ .450 lift then eventually recovered
to 246 by .650 (useless I know) however not really sure why this happened
I guess thats all I have for now till I get some chassis numbers to verify if
I waisted my time or not but this site has been extremely helpful and I'm
open to suggestions or insults
with only 15 thou on it. Absolutely stock except a Corsa X with Pacecar
axle-back. I didn't dyno it but suspect from others on here maybe would have
done about 310-315rwhp. I picked up an ls2 chain and oil-pump O-ring from
TSP and an EPS 218-.595/ 226-.598 117+3deg. I'm reusing the oil pump and
rockers since such low mileage. Special thanx to RED98C5 for the new LS6
valves shipped @185..I also went w/ Lunati GOLD dual kit for $225(good deal)
Since its still in the 30s and 40s here in WIS I'm in no extreme hurry to slap
this thing back together as this is my first LS modding(wanna do it right)
When it's all together I'll be taking it to Speed Inc. in Shaumburg, Ill for the
tune and chassis dyno. Since I gasket matched the EX. manifolds I guess
I'l be happy with anything over 360 to the ground. While waiting for the cam
I couldn't resist pulling the 241s and really wish I had the coin to send to AI
but ultimately decided to mess with them myself after reading some of the
success stories on here.
I'd first like to state that I've ported at least a hundred sets of heads over
25 years of engine building but never had any of them flowed and this is my
first screwing with an LS head. I decided to keep it to a minimum as I would
be happy with any improvement and didn't want to F#@K them up.
I didn't flow them B4 but decided to use Advanced Inductions stock #s
as my comparison:........................Mine flowed: no pipe...... ex. w/pipe
.100...................66-55.............................65-54..................54
.200..................139-101.5.......................135-97.5..............101
.300..................193-136..........................196-130...............137
.400................215.5-160..........................234-168...............180
.500..................226-171.......................... 240-191...............198
.550..................231-176...........................241-197...............215
.600..................233-180...........................244-201...............221
EX w/o pipe 3.9 bore fixture
I guess I'll take the minimal improvement based on my total time invested
of less than 4 hours. I also left the factory valve job and lapped the new ls6
valves. The time breakdown is just shy of 1.5hrs on the intakes with carbide
cutting the rocker boss(leaving it rough) and 80 grit blending the bowls. I
didn't touch the swirl ramp in the bowl or the guide boss.
Also just under 2.5hrs. on the exhaust with blending the bowls, streamlining
the guides and gasket matching the roof and sides(left the floor alone)
Side note: the intake spiked 245.5 cfm @ .450 lift then eventually recovered
to 246 by .650 (useless I know) however not really sure why this happened
I guess thats all I have for now till I get some chassis numbers to verify if
I waisted my time or not but this site has been extremely helpful and I'm
open to suggestions or insults
![The Patriot !!](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_patriot.gif)
Last edited by A.R. Shale Targa; 04-24-2011 at 08:38 PM.
#3
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45 deg. seat was only about .040" wide (not too bad of shape), while not
the optimum for flow it'll have to do as a $175 valve job didn't make the
budget......Thanks for the suggestion though
#4
TECH Fanatic
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My home-ported 241s flowed with the same spike at about .450 on the intake (although my numbers were higher since I spent more time on them). The shop where I had them flowed said they've seen that before on some LS heads, even some stock versions. They said they could correct it (didn't say how) with about 2 hours work but I declined.
#5
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i also had a set of 241's worked over by Airflow Development. Did a valve job on them, and some bowl/throat work. I can tell you for certain, that a good valve job on these heads will make the most difference. The factory valve job just isnt very good, period.
#7
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My home-ported 241s flowed with the same spike at about .450 on the intake (although my numbers were higher since I spent more time on them). The shop where I had them flowed said they've seen that before on some LS heads, even some stock versions. They said they could correct it (didn't say how) with about 2 hours work but I declined.
cfm @ .500 and didn't recover till like .650 or .700. I'm wondering if it's a
situation where the runner volume and the area between the valve and seat
@ a certain lift meet a happy spot. 241's with 204cc spiking @ .450 and 243's
with like 214cc ??? working best @ .500. I maybe only increased the runner
volume on mine by 2-3 cc not enough to support the higher valvelifts, but
10 to 12 cfm improvement for literally about 12 minutes of time per intake
runner, I'll take that for now. Total cost was nothing !!!
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#8
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effective valve job. There's typically 3 angles; the inner transitions the bowl
to the seat, narrowing the seat and moving it out on the valve, and the
outer angle transitions the seat to the chamber. I know the comb. chamber
wall next to the in. valve is a downfall of the 241 and if a shop sinks the
seat that hurts also as the 241 port floor to bowl transition is nowhere near
as good as the 243 casting... thanx for the response
#9
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and others say more. I have 7.400 push rods already as Geoff recommended
7.425 for the cam I have but with milling the heads .030 and the slightly
longer valves. I definitely will double and triple check since the last thing I
wanna become is another noisy valvetrain thread......ugh
#10
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I recently discovered that these LS6 valves are 0.6mm or .0236" longer than
my stock valves....hoping my lifter preload will work out given the .070 or so
smaller base circle of the new cam
Any predictions or guesstimates of rwhp ???? Not sure what kind of dyno
Speed Inc. has (I would assume that could influence the results)
my stock valves....hoping my lifter preload will work out given the .070 or so
smaller base circle of the new cam
Any predictions or guesstimates of rwhp ???? Not sure what kind of dyno
Speed Inc. has (I would assume that could influence the results)
#14
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Cam is finally in, new ls2 chain, p/u o-ring, and I ported and shimmed the oil
pump. Tried to post a bunch of b4 and after pics of pump but had epic fail ???
Balancer is on and new GM bolt @ 140 deg. after 35 ft/lb. Tonight I only got
the pistons cleaned and head bolt holes thread chased. I wish I had more time
after 13-14 hour work days
....Hopefully I can figure out what I'm doing
wrong with pics since I know all threads are worthless without them
pump. Tried to post a bunch of b4 and after pics of pump but had epic fail ???
Balancer is on and new GM bolt @ 140 deg. after 35 ft/lb. Tonight I only got
the pistons cleaned and head bolt holes thread chased. I wish I had more time
after 13-14 hour work days
![Bang Head](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_banghead.gif)
wrong with pics since I know all threads are worthless without them
#17
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UPDATE....ITZ ALIVE !!!!!!![Grin](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_grin.gif)
![Grin](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_grin.gif)
![Grin](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_grin.gif)
Finally got after it yesterday and today...she fired right up, rattled the
rockers for a few seconds then silent, excellant oil pressure 60 cold and 40
hot. After up to operating temp the valvetrain is marginally louder than stock
completely liveable. Made a last minute change and ditched the ported manis
for some ceramic coated BBK shorties (I know less than ideal) but they fit real
nice, look good, and shed 25 lbs off the nose. I also found a NAPA donut
gasket 31508 which measured 2 and 9/16 ID. This fit both the collector and
the factory exhaust flange perfectly. The headers didn't come w/one and the
factory donut measured 2 and 5/16 ID. I guess you'ld call that an intellectual
improvement (sleep better). I'm real impressed with the driveability on stock
tune. This thing sounds stock which is what I wanted but I thought it would
take a slight tune to get that. The wife noted that it's slightly louder when
we went to the fireworks tonight. Car is scheduled to hit Speed Inc. on Fri
July 29th....Hoping for 360-365 @ the tire and maybe some Nittos, perhaps
mid twelves.
http://www.corvetteguys.com/ceramic-...t-headers.html
![Grin](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_grin.gif)
![Grin](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_grin.gif)
![Grin](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_grin.gif)
Finally got after it yesterday and today...she fired right up, rattled the
rockers for a few seconds then silent, excellant oil pressure 60 cold and 40
hot. After up to operating temp the valvetrain is marginally louder than stock
completely liveable. Made a last minute change and ditched the ported manis
for some ceramic coated BBK shorties (I know less than ideal) but they fit real
nice, look good, and shed 25 lbs off the nose. I also found a NAPA donut
gasket 31508 which measured 2 and 9/16 ID. This fit both the collector and
the factory exhaust flange perfectly. The headers didn't come w/one and the
factory donut measured 2 and 5/16 ID. I guess you'ld call that an intellectual
improvement (sleep better). I'm real impressed with the driveability on stock
tune. This thing sounds stock which is what I wanted but I thought it would
take a slight tune to get that. The wife noted that it's slightly louder when
we went to the fireworks tonight. Car is scheduled to hit Speed Inc. on Fri
July 29th....Hoping for 360-365 @ the tire and maybe some Nittos, perhaps
mid twelves.
http://www.corvetteguys.com/ceramic-...t-headers.html
Last edited by A.R. Shale Targa; 07-10-2011 at 11:00 AM.
#18
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Hopefully this will add some interest to this thread....
http://www.fquick.com/JimGwen
every time I tried to atttach this it would say invalid link...not sure why
Drove the car to work this week as the weather was real nice. My commute
is 45 miles each way and between 1400-1500 rpms I'm getting OVER
30 mpg according to the dash. I suppose I'll calculate it out
after the tune. Very happy so far.
http://www.fquick.com/JimGwen
every time I tried to atttach this it would say invalid link...not sure why
Drove the car to work this week as the weather was real nice. My commute
is 45 miles each way and between 1400-1500 rpms I'm getting OVER
30 mpg according to the dash. I suppose I'll calculate it out
after the tune. Very happy so far.
Last edited by A.R. Shale Targa; 07-10-2011 at 10:50 AM.
#19
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Finally had the car tuned yesterday and things went well. I was pretty happy
w/the drivability of the car on the stock tune BUT I now know why people
say find a GOOD tuner. Speed Inc. brought this car to a new level of crisp-
ness. For a shop of their capabilities this was probably a yawn of a job. Side
note: I was stoked that my car was being tuned by the owner of the black
sleeper Malibu (lq9 w/twins) in the tens. He laughed @ the 69 4dr. IMP that
I just sold..primered green 385 w/s475 blothru....some know it as GUMBY.
Anyways the lowdown on the gragh was right on my predictions. It made
365.48 @ 6300 and carried smooth til 6700. Torque was 344.57 @ 5100....
also TQ was over 300 from 2650-6350 rpms. Air/fuel ratio was at or just
below 13 throughout. By no means world beater #s but I'm happy with
the increase in power, continued reliability, mileage efficiency, and total cost
investment of 2 grand. Hopefully now I can line up against my Father-in-law's
new 5.0 Mustang and not worry about embarrassing myself.....track results
in the near future.....Nittos, clutch, blah, blah, blah,cold-shot
w/the drivability of the car on the stock tune BUT I now know why people
say find a GOOD tuner. Speed Inc. brought this car to a new level of crisp-
ness. For a shop of their capabilities this was probably a yawn of a job. Side
note: I was stoked that my car was being tuned by the owner of the black
sleeper Malibu (lq9 w/twins) in the tens. He laughed @ the 69 4dr. IMP that
I just sold..primered green 385 w/s475 blothru....some know it as GUMBY.
Anyways the lowdown on the gragh was right on my predictions. It made
365.48 @ 6300 and carried smooth til 6700. Torque was 344.57 @ 5100....
also TQ was over 300 from 2650-6350 rpms. Air/fuel ratio was at or just
below 13 throughout. By no means world beater #s but I'm happy with
the increase in power, continued reliability, mileage efficiency, and total cost
investment of 2 grand. Hopefully now I can line up against my Father-in-law's
new 5.0 Mustang and not worry about embarrassing myself.....track results
in the near future.....Nittos, clutch, blah, blah, blah,cold-shot
![Grin](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_grin.gif)
#20
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i just installed one of geoff's cam's, on my 2001 b4c camaro.i'm still running the stock manifolds.i went from a cheatr v3 to a cam geoff deseigned for me.i was looking for a little lope.after the car warms up,it's goes into a nice chop.will be going see him in 2 weeks to get it tuned and dynoed.i would be very happy with the numbers you came up with.i went the best of 12.09 with the cheatr cam.