05-28-2020, 10:52 AM | #169 |
Drives: SS 6 speed of course Join Date: Jan 2016
Location: Hilo, HI
Posts: 4,316
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The Olds head is like the 1968 up 440 Dodge head, it has an open combustion chamber:
https://www.cartechbooks.com/techtip...cylinderheads/ 30 to 40 years ago Hughes made a piston specific to the 440 that would take away all the quench and squeeze the charge into a small area. These were odd shaped positive deck pistons and had to be clay-ed to each piston chamber. It allowed me to run 10.5 pistons on pump gas across the HUGE 440 piston. Any modern chamber is basically a heart shaped head and a positive deck piston so ally action happens in the heart at TDC (no quench). Looking at the Olds head you are stuck with large chamber (unless somebody makes a specific piston for it). Probably going to have to drop 1 point or 1.5 points to run 92 octane. 5% loss in power for each point (you got plenty). What is your CR right now? My 2nd build on my 440 I had 11:0 forged and that was good till the early 80s, that when I went with the Hughes piston which worked till I sold the car a few years ago. If I did not do a Hughes piston I would have done 10.0 or 9.5, that is just the reality of the chamber design and the large bore.
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Forged short block, large duration sub .600 lift Cam Motion cam, 7200 RPM fuel cut, Pray Ported Heads, 3.85 pulley D1X, stage II intercooler, DSX secondary low side, DSX E85 sensor, Lingenfelter big bore 2.0 pump, ported front cats, 60608 Borla, LT4 injectors, ZL1 1LE driveshaft and Katech ported TB, ported MSD intake, BTR valvetrain, ARP studs, ProFlow valves, PS4 tires.
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05-28-2020, 11:05 AM | #170 |
Drives: 80 Cutlass 403, 2010 FF RT Join Date: Jun 2014
Location: Ontario
Posts: 921
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I am in the range of 10.5 to 11 to 1 my heads were 64CC to start with but with limited forged pistons to choose in 99 had to take a dished piston, in order to bring compression back up the heads were decked and material was taken out to reduce CC and up CR, I have done a measurement on a stock set of heads I have and it was close to 1/8" taken so will need to keep a dished piston and go with a thicker gasket.
In Ontario Sunoco 94 is the highest octane that you can get so I will run it on that so thinking that 9.5 to 10 would be the CR to go with.
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05-28-2020, 11:18 AM | #171 |
Drives: SS 6 speed of course Join Date: Jan 2016
Location: Hilo, HI
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roger that
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Forged short block, large duration sub .600 lift Cam Motion cam, 7200 RPM fuel cut, Pray Ported Heads, 3.85 pulley D1X, stage II intercooler, DSX secondary low side, DSX E85 sensor, Lingenfelter big bore 2.0 pump, ported front cats, 60608 Borla, LT4 injectors, ZL1 1LE driveshaft and Katech ported TB, ported MSD intake, BTR valvetrain, ARP studs, ProFlow valves, PS4 tires.
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05-28-2020, 09:05 PM | #172 | |
Drives: 2018 1SS Join Date: May 2015
Location: FL
Posts: 184
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Quote:
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05-28-2020, 10:47 PM | #173 |
Drives: SS 6 speed of course Join Date: Jan 2016
Location: Hilo, HI
Posts: 4,316
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yep they were gold heads back in the day.
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Forged short block, large duration sub .600 lift Cam Motion cam, 7200 RPM fuel cut, Pray Ported Heads, 3.85 pulley D1X, stage II intercooler, DSX secondary low side, DSX E85 sensor, Lingenfelter big bore 2.0 pump, ported front cats, 60608 Borla, LT4 injectors, ZL1 1LE driveshaft and Katech ported TB, ported MSD intake, BTR valvetrain, ARP studs, ProFlow valves, PS4 tires.
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07-14-2021, 04:32 PM | #174 |
Drives: SS 6 speed of course Join Date: Jan 2016
Location: Hilo, HI
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The latest Pure Stock Drags shows a move to thee engines that are surprisingly strong:
340 cid both 6 pack and thero-quad Olds 350 W31 / ram rod now closing on 350 net HP.... 350 LT1 the latter two hampered by poor exhaust manifolds but the 2.5 mandrel exhaust allowed (and two mufflers) is really letting these engines work https://www.psmcdr.com/pastyears
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Forged short block, large duration sub .600 lift Cam Motion cam, 7200 RPM fuel cut, Pray Ported Heads, 3.85 pulley D1X, stage II intercooler, DSX secondary low side, DSX E85 sensor, Lingenfelter big bore 2.0 pump, ported front cats, 60608 Borla, LT4 injectors, ZL1 1LE driveshaft and Katech ported TB, ported MSD intake, BTR valvetrain, ARP studs, ProFlow valves, PS4 tires.
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07-18-2021, 12:36 AM | #175 | ||
Drives: Camaro Super Sport, Six on the Stik Join Date: Jul 2021
Location: Earth
Posts: 308
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Quote:
Having said all that...all the test cars were traction limited. Either the throttle was feathered coming off the line to control traction or they just stomped it and spin the tires through most of first gear. Look at some of Bud Lindenmen's tests from the 60s and 70s, they were smoking the tires in these e/t tests. Last edited by Nilly Welson; 07-18-2021 at 12:41 AM. Reason: kkd |
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07-21-2021, 01:29 PM | #176 |
Drives: SS 6 speed of course Join Date: Jan 2016
Location: Hilo, HI
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I'm glad I started this post:
1) The Shelby Cobra should stay on the list but it went 13.2 on blue dots. That 12.2 was a quote for Shelby himself and was NOT in any form related to a Cobra customers could actually get. The article itself is a mess, actual testing of the car in the article was 13.2. 2) The 340 that are performing are the 6 pack and the thermoquad 1970, both excellent setups, but only for 1 year, before the CR drop. I will say that even with the CR drop the 340 was rated at 240 net with thermoquad and OK exhaust manifolds. 3) The Olds 350 and the LT1 1970 (every chevy SB) have poor exhaust manifolds the Olds is the worst (one side) as the other side is bigger because most 350 Olds engines came with single exhaust one side manifold feeding into the other side (which had bigger passages, by a little). Added that many FBody upto 1969 if not all came with only ONE muffler, a traverse one in the rear. The exception that I know of is the Z/28 chambered exhaust, I had one and it was HECK of loud. Don't think it flowed all that well either. Since the pure stock rules allow 2.5" mandrel exhaust cars like the ZL1 1969 Camaro are probably making 50 more HP just going from a single muffler to twin 2.5" free flow mufflers. Mopar IMO of course always had a nice twin muffler setup for the factory.
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Forged short block, large duration sub .600 lift Cam Motion cam, 7200 RPM fuel cut, Pray Ported Heads, 3.85 pulley D1X, stage II intercooler, DSX secondary low side, DSX E85 sensor, Lingenfelter big bore 2.0 pump, ported front cats, 60608 Borla, LT4 injectors, ZL1 1LE driveshaft and Katech ported TB, ported MSD intake, BTR valvetrain, ARP studs, ProFlow valves, PS4 tires.
Last edited by oldman; 07-21-2021 at 01:41 PM. |
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