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#1
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Okay, here's my dilemma...
440 Punched .040 over... TRW 2266 flat tops...906 ported / polished heads... (2.14/1.81 vavles)...Milled .010 Measured P to V clearance with checking springs and found out the following: Intake valve Cylinder 1 TDC has .375" clearance Exh valve Cylinder 1 TDC has .416" clearance I was trying to calculate what cam to purchase from Hughes (leaning towards the HE3844BL .536 Intake / .540 Exh lift and 238/244 degrees (Int/Exh) duration a@.050) and how much more I could shave my heads if any... Hughes does not have a Tappet lift at TDC measurement on their cams... So how do I know what will fit. I'd like to have the .090 clearance minimum but also mill the heads some more to get some more compression.... Help... I was trying to use the method: (P to V clearance Plus Head Gasket Thickness) minus ((Tappet Lift of cam at TDC) x (1.5 rocker ratio) - Lash) ..... and hopefully have atleast .090 left over... Am I doing this correctly... Any help will be appreciated... |
#2
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Where did my piston go?
Oh great...
I also just measured my Piston to Deck height and my piston is so far down in the hole, it's ridiculous... .185 in the hole... I know I can't get good compression without new pistons, but I'm not pulling the motor this year... So my options are to button it up with a few speed parts and run it out... I still need a cam and any help with the above question is appreciated very much... Thanks again... |
#3
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toss the 2266 trws!!!! you will never make power with that compression.. get some flat top ross pistons , they have valve pockets for roller cams....also their much lighter..... I'm not sure why trw even make that 2266 piston.... if you dont want ross trw does make a true six pac piston with valve pockets, there not to deep but should fit a cam to 509 specs.. i think the part number is 2355. you can make the 2266 work some what, here is what i have done to 3 motors with that piston... (1) mill the heads 60 and use the steel 19 thou m/p gasket and drop the cam size down to 280 480... this can get a 3800 b body in to the high 12s on pump gas with 35 deg timinng and no pinging...(2) find some 915 or 516 closed chamber heads.... either way you will come up with around 9.5.1..... with the 2266 and 906 heads and felpro 1009 gaskets you would be lucky to get 7.5.1..hope this helped you some....Lee..
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#4
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Yeah, I know...I'm already depressed....
I'm not sure what to do.... I'd rather not pull the motor...it' not very old and runs decent... I was told mistruth's about what it had in it... and now after tearing off the top-end, I can see why it was a dog... Thanks for the info... |
#5
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Perfect for a Supercharger! Ahhhhhhhh, the sound of a 6-71 is filling my ears now. How sweet it is. (Just a thought)
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#6
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SuperCharger would be neat... Too much money though...
Okay how about the MP .484 cam.... That's a good performer for lower compression motors isn't it? I should be able to get my compression ratio to 9:1 or so... I hope... Any thoughts???? |
#7
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Heres a bit of interesting info concerning p/v clearance.Lift under .530 is not what makes the clearance close but duration,obvoiusly lift is a factor but duration is more critical,on the compression stroke usually you have adequate p/v clearance with a streetable cam but try it with a cam that has 320*(usually a solid) and youll find that interference is very common making pockets nessecary. .185 in the hole!!!!!! man why run pistons at all!!!! man thats gotta be some low compression I know on a 383 I built they were .100 in the hole with 8.5:1,Id go real conservative like the mp 455/272 or so,or is it too late to deck the block? you could also mill the heads another .050,dont forget to mill the intake too and use rockershaft shims to adjust lifter preload.....PRO......
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#8
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speed pro makes a 280 480 on a 108 center line that works great with 9.1.0+ its sold under speed pro,fed mogal and trw... this is the cam i used to repair them nasty 2266 pistons....Lee...
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#9
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Measured Again...
I measured the rest of the piston / deck height to see if I made a mistake... They are all hiding in the hole equally deep... How about a higher lift shorter duration cam... Like
225 - 230 degrees duration at .050 and maybe around a .510 lift or so... Advanced 4 degrees minimum... You know this car still beat most of the new Modified Shivvy F-bodies and Vettes with the LS1's at the strip... So I can't hate it too bad... It ran 14 at Bandimere and Low 13's in Arizona.. I now know why it did not ever run 12's... What do you think of this combo.... Need to put this thing back together soon... Next year I'll pull the motor... |
#10
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Sublime440, What is the rest of the engine and drivetrain setup? I have seen some low compression engines run OK with big cams, but the car was setup for high RPM power, not torque.
I would cc the heads to see what you have now, and use calculate your real compression ratio, then pick a cam that won't totally kill low end power, but the trick may be to run a a low first gear if you have an automatic, along with a high stall converter and some 4.10 or 4.30 gears. You may be able to pick-up some speed in other parts of the car. Maybe a fresh air intake, race transmission, lighter weight driveshaft or wheels? What I'm saying is look at the places that will pick-up power or ET besides the engine, and that are compatable with more power for when you are ready to rebuild the engine. If this is a bracket car maybe money spent on making it more consistent would be better than dropping alot of money in a mis-matched engine combination. You might look into ignition and fuel system upgrades for consistency and to be ready for the new engine when the time comes. |
#11
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Here's what I got...
70 Challenger.... 3740 Lbs w/me in it....
Currently: 440 punched .040 over... Hemi 4 Speed... 4.10 8.75 rear end... 1 5/8" headers (Car came with them)... Stock cam...516 heads small valves... (1.60 exh) Holley Blue Fuel Pump.... Edelbrock Performer RPM w/ Holley 850 Double Pumper... MP Electronic Ignition w/Chrome box.... Weld ProStar wheels all the way around w/ 28.50 tall tire in back (ET Streets) Skinnies up front... Car died at 5000 RPM last year... Parts I have acquired (Ebay, etc...)to add: MSD Pro-Billet Dist... and 6 AL Box... 906 Milled Ported/Polished Heads w/2.14 and 1.81 vavles... Need to pick the cam... Thinking about 1 7/8" headers if that would make a difference... Also scored some Harland Sharpe Roller Rockers and Fluid Dampner.... Have a new RAM AIR (w/big tubes) K&N filter system .... Line Locks... Oh yeah...Double Roller Timing Chain Set...let's see anything else...I think that's it... I don't want to buy ALOT of parts that I CANNOT reuse on a new performance motor... (Plan on rebuild next year at higher compression for Denver)... So I'm buying parts that can carry over to that.... PS: I just read an article in Car Craft (July/Aug '2000)... where they recommend oversized cam's and headers to make high end RPM on low compression motors... but the motor (454 RAT) suffered some on the low end torque... Cranked out almost 450 HP and 500 Ft Lbs torque on engine dyno... (From 8:1 motor out of old pickup truck.. They added a Crane Saturday Night Special cam I believe ... around .560 lift and 240 duration at .050 and then wanted to put 2" headers on ....from the 1 7/8" headers to help motor run flow with no compression....???? works for me since I'm in that same boat..) I would love a 12.99 out of this car... What do you think 451 Mopar... You live out here.... Need to figure out a combo... even mismatched (Again don't want to buy alot of throw away parts on this motor...need to apply them to decent compression motor next year...) I'm looking at used cams (Don't mind throwing them away if I don't have alot of money invested)... But need to use 906 heads that I bought and rest of ignition, fuel pump, Dampner, Roller Timing Set, etc... can be reused next year.... Any suggestions on Cam... Maybe 1 7/8" headers and let's turn some RPM's .... Help.... |
#12
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I think the Hughes or comp High Energy cams would work better, but on the budget side, and with your 4-speed and gears you could probbly drop in one of the Mopar 284/0.484" cams and use mild (in comparison) general performance valve springs.
I think I have seen the Mopar cams with lifters for about $130 from Summit or Jegs. The 292/0.509" cam may work too, but your going to give up alot of low end torque with the low compression you have. I don't think you'll notice much difference in ET between the the 1-5/8" and 1-7/8" headers since this probbly won't be a real high reving engine anyhow and the smaller headers may help with low end torque. The new heads should make a good increase and the MSD6 will help ignite the fuel better. |
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