Does anyone know what the stock compression ratio is? How much hp could I pick up if I bumped the ratio to 11.0:1? Could I get away with 93 octane or do I need something higher?
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'90 Mercury Grand Marquis GS
Baseline 5.0L numbers totally stock, 123 rwhp, 239 rwtq
5.4L swap coming soon. -
9:1...you could get away with 93 and 11:1, but you'd have to be really conservative with the timing. Anyway, with the way gas prices are going..WHY?Builder/Owner of Badass Panther Wagons
Busy maintaining a fleet of Fords -
11:1 compression would mean about 10 deg of base timing and require at least 100 octane gas also very carefull selection of cam heads and pistons to prevent piston to valve contacthttp://secondhandracing.com/Home.aspx
http://secondhandradio.com/
R.I.P. Jason P Harrill 6-12-06
http://www.grandmarq.net/vb/showthread.php?t=5634Comment
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I don't worry about gas prices. The gas card is paid once a month. What's the highest ratio with E7TE heads, 9.5:1 or 10.0:1?
'90 Mercury Grand Marquis GS
Baseline 5.0L numbers totally stock, 123 rwhp, 239 rwtq
5.4L swap coming soon.Comment
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As high as you want. All depends on the pistons and heads. And the valve clearance...Builder/Owner of Badass Panther Wagons
Busy maintaining a fleet of FordsComment
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Also, with a higher compression motor, it will run hotter.
You will want a killer cooling system...1983 Grand Marquis 2Dr Sedan "Mercules"
Tremec TKO conversion, hydraulic clutch, HURST equipped!
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you probably want to make sure you build a nice strong bottom end if you're running that level of compression. Also good quality head bolts and gaskets are a must.86 Lincoln Town Car (Galactica).
5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley
91 Lincoln Mark VII LSC grandpa spec white and cranberry
1984 Lincoln Continental TurboDiesel - rolls coal
Originally posted by phayzer5
I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousersComment
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you wont get 11:1 without new pistons. If you tried decking your block and heads to get near 10:1 you'd more than likely have issues with your intake not matching up
RIP Jason P Harril, we'll miss ya bro
'80 Town Coupé
'84 Towncar - Teh Cobra TC, 408w powered
'16 Ram 1500 CC Outdoorsman, Hemi/3.92/8sp 4x4Comment
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Thanks for the info.
'90 Mercury Grand Marquis GS
Baseline 5.0L numbers totally stock, 123 rwhp, 239 rwtq
5.4L swap coming soon.Comment
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You have to match all your components. With the correct cam and with aluminum heads, you can possibly run 93 on the street. The gain from compression alone is ~4% per point. So going from 9:1 to 11:1, you'd gain ~8%, or ~20 hp on a stock HO. Assuming you could fuel it, which you basically couldn't. Add the right cam and heads (and other parts) and you'll get a hell of a lot more than 20 hp....FOR SALE: 89 Grand Marquis GS HO. Quarter mile = 15.8 @ 87mph -- pics http://public.fotki.com/vfr700f2/car...rcycl/mercury/
Junkyard HO, MSD wires, stock Mustang headers, off-road H, Hemi Super Turbos. 3.55 trac loc, HO governor and servo in stock rebuilt AOD. 3-row rad, air pump delete, cop rear bar, wagon rear springs, 93 CV rear discs, 98-02 Grand Marquis wheels, Class 3 hitch, aluminum space-saver spare.
Coming soon: 98-02 front brakes, cop springs, Monroe cop shocks, 96 Cobra wheels w/255/50/17. Better yet, need a nice wagon to put all that stuff in.Comment
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