Swirl 782 vs G 287, 87 Shelby Lancer

[unluckyty]

Well hit the track last night.To see were I am at with the SL. Times were surprisingly close, with the 287 G / bathtub head. Replaced because of unusable stock 782.

2.20 60'
6.01 330'
8.61 594'
9.19 1/8 @ 76.54 mph
11.93 1000'
14.33 1/4 @ 94.16 mph

782 swirl head
2.15 60'
5.97 330'
8.57 594'
9.17 1/8 @ 76.15 mph
11.90 1000'
14.30 1/4 @95.12 mph

The G head was shaved .018. With Fwd 3 bar cal(w/ supporting mods) for stock head, turbo, intercooler, auto with 2.5 exhaust. Started to hear some slight detonation at any boost over 15#. I have a copper shim, unsure thickness, that I''ll throw on next. Would really like to run 18-20# boost and hit the 13's.

Greg

[glhs875]

Well hit the track last night.To see were I am at with the SL. Times were surprisingly close, with the 287 G / bathtub head. Replaced because of unusable stock 782.

2.20 60'
6.01 330'
8.61 594'
9.19 1/8 @ 76.54 mph
11.93 1000'
14.33 1/4 @ 94.16 mph

782 swirl head
2.15 60'
5.97 330'
8.57 594'
9.17 1/8 @ 76.15 mph
11.90 1000'
14.30 1/4 @95.12 mph

The G head was shaved .018. With Fwd 3 bar cal(w/ supporting mods) for stock head, turbo, intercooler, auto with 2.5 exhaust. Started to hear some slight detonation at any boost over 15#. I have a copper shim, unsure thickness, that I''ll throw on next. Would really like to run 18-20# boost and hit the 13's.

Greg


What boost were you running with the swirl (782) vs. G (287)?

[unluckyty]

17# boost in third for the swirl.

Just rechecked my ignition timing, making sure it was at 12^. Was running at 14-15^. Reset and can run 17-18# no problem.

Greg

[contraption22]

What are the combustion chamber CC's of each head?

[turbovanman²]

Interesting for sure, :thumb:

2.2 I assume?

[Spraynlog]

That is interesting! I thought I'd heard the 287 head would flow 10% better, so I wonder why it didn't do better?

[1984rampage]

That is interesting! I thought I'd heard the 287 head would flow 10% better, so I wonder why it didn't do better?

From what I read the G-head combo did the same time with 2-3 pounds less boost...

[unluckyty]

What are the combustion chamber CC's of each head?

Don't know, unfortunatly.

Still a 2.2, Simon.

Greg

[unluckyty]

That is interesting! I thought I'd heard the 287 head would flow 10% better, so I wonder why it didn't do better?

But suppose to have 10% less torque. I do believe the shave .018 is to my benifit with the the set up I'm running.

Greg

[glhs875]

2 more psi could easily be worth 2 tenths in the 1/4.

[4 l-bodies]

Resurfacing the head .018 without advancing the cam? Running a g-head on a swirl calibration? Lowered compression because of the g-head. Too many variables for me to draw any conclusion from. Funny it ran as good as it did.:thumb:
Todd

[unluckyty]

Car ran better, with timing set to 12^, but not as well as I had hoped. Still didn't like any boost above 17-18#.

New best though.

2.10 60'
5.87 330'
8.46 594'
9.04 1/8 @ 76.91 mph
11.77 1000'
14.14 1/4 @ 94.75 mph

Did have a best mph of 14.33@95.62 with my poorest 60' of 2.25. That run had the potential to be a 13.99-14.0. o'well, time to work on the Dart for a change, till I get some things sorted out for the Shelby.

Greg

[Juggy]

Car ran better, with timing set to 12^, but not as well as I had hoped. Still didn't like any boost above 17-18#.

New best though.

2.10 60'
5.87 330'
8.46 594'
9.04 1/8 @ 76.91 mph
11.77 1000'
14.14 1/4 @ 94.75 mph

Did have a best mph of 14.33@95.62 with my poorest 60' of 2.25. That run had the potential to be a 13.99-14.0. o'well, time to work on the Dart for a change, till I get some things sorted out for the Shelby.

Greg


nice runs! you always get a better mph on the crappier 60' runs because you essentially have more time to make more MPH, because your ending et time is slower