XD408

Hey guys

I ve posted in here b4 the details of my combo so far on pump fuel has netted 459rwhp and 530lbs/ft after driving it for a while gotten use to the power and want more i know my cams big but not huge as its a Comp Cam solid roller with 670thou lift but only 248 and 250 something duration(ive lost my cam sheet) and the compressions 11.1. With the Eagle crank 6.2 rods and matching forged Arias pistons was damn close on piston to valve clearance obviously to get more power more compression and a bigger cam is needed i just didnt want to lose its streetability or have to change my pistons. any suggestions of what cam and what compression to use to get closer to 550rwhp. (the heads flow 700HP at 680thou and are the 3v 218s)

philstoj

if you fit a bigger cam with bigger lift you will have worse valve to piston clearence...if you want more compression, you will have to deck the block, or the heads, and in turn that will give you clearence issues again..
give it a shot of NOS

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Terrorising a crap driver near you!

brenx

Have you looked at a cam that has more duration and not as much lift? Thats where I am heading. I'm going to attempt to get 500hp @ the wheels. Running nothing more than a 4500rpm convertor and 4.11 gears. So I won't loose drivability. My projects still in planning at this stage.

Brenden

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XB Fairmont (street car) 11.07@123.02mph.

STROKEXD

Give it a hit of gas..

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XD408

I had given thought to NOS id prefer to make that power on the engine than play around with a small shot later the with the size of the engine and the heads that are on it 550rwhp shouldnt be a problem just not sure what cam and compression to run.

xdclevo

Duration is where it's at! Look at the good old F246. It only has 570 lift, but with 246/256 duration at 50th, and they are a great performance cam.
p.s, you are a greedy little bugger........

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10.70 @ 125.00 on the black fun top
408 Cube Cleveland.

russxr67

Making more power out of a combo like that would be simple enough .Remember that you have some 60 cubes more than a conventional 351 so what may seem a radical street cam in a 351 will have been tamed down by the extra cubes.If you want more horsepower then you have to cram more air/fuel into the chamber.I would certainly look at more camshaft as number one priority in this equation.I have personally run a 260/263 degree cam on a street 351 with 2v,s and with appropriate gearing(t/loader,vertical gate and 4.11 locker)and the vehicle was very streetable.Keep in mind that if you move your power band further up the rpm scale you will probably lose it down low .
You may even have to flycut for greater piston to valve clearance which is commonplace anyhow.
What size pipes are you running on your xd ?

falcon coupe

Is your car auto or manual ?, as you will have to change stall size with a cam change, personally i think your lift sounds good, but as Brenx said i would go more duration, something along the lines of at least 272/280 @ 50,with 106 lobe seperation, that would really wake it up.
I am going 262/270 on my 351.

XD408

Hey guys

Thanks for the replys, in response yeh i didnt really want to have to go to much bigger on lift its at 670 thou now and is pretty close so i guess to go to 690-700 thou lift i am going to have to fly cut the pistons but wouldnt that inturn lower my compression?? I had heard that the more cubes u had the more tame a big cam became so going for a a 270-280ish durationed cam wouldnt cause to much problems with streetability, ive been looking at Comp Cams camshafts and couldnt find one that didnt increase in lift as the duration increased any suggestions as to what cam to use??? and having the alloy heads getting the compression to 12.1 isnt going to have to much baring on the fuel i use (I run U98 with the occasional octane booster but doesnt even ping on premium unleaded). Im currently running those pacemaker extractors with the 2" primarys and 3.5" collectors through a twin 3" exhaust dumped behind the diff with straight thru mufflers (459rwhp was with twin 2.5 and straight U98) and a full manualed c4 with a dominator 4500stall and 4.11s. I honestly thought id never get use to the power and want more but its only been running 6 months and were talking bout pulling it out