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-   -   BBC hyd roller cam help (http://www.hotrodders.com/forum/bbc-hyd-roller-cam-help-224978.html)

jumbo2 10-14-2012 02:21 AM

BBC hyd roller cam help
 
I have a .30 454 with forged domes 29.7cc and am running stock 781's so comp should be 9:5-1 , also picked up some comp cams retro hyd roller lifters for a song and dance in the box so looking for a cam . street/strip use 2500-3000 stall , air gap , demon race 850 and msd digital 6 , big headers and exhaust, 3500lb truck with 9 inch and 3:73 with 31 inch tire , dont care about chunky idle looking for 6000-6200 redline and maybe 150 shot once and a while

comp X energy xr288xr looks good , not sure of the magnum family or if I have to run a comp cam

cdminter59 10-14-2012 08:09 AM

BBc Hyd Roller
 
The cam you are looking at XR288HR looks good on the dyno from CamQuest. Also look at 290HR 11-450-8 2500-6200, .578/.578 232/232 432 hp @ 5000 and 502 lbs of torque @ 2500 rpms.

jumbo2 10-14-2012 11:44 AM

can go solid dont have the $$ its either flat tappet or hyd roller , like to be closer to 500hp

vinniekq2 10-14-2012 12:26 PM

a 400 horse rat will make the 3500 pound truck run into the 11s. How did you decide on 500 hp?Buy a set of aluminum oval port heads if you want 500 hp.If you are racing,I would think awhile about camshafts. Are you looking for low or high rpm?If its 6k or lower,use the hydraulic roller.over 6k you should consider a solid cam.Big blocks need a few goodies to live at higher rpm s

jumbo2 10-14-2012 01:33 PM

Quote:

Originally Posted by vinniekq2 (Post 1599007)
a 400 horse rat will make the 3500 pound truck run into the 11s. How did you decide on 500 hp?Buy a set of aluminum oval port heads if you want 500 hp.If you are racing,I would think awhile about camshafts. Are you looking for low or high rpm?If its 6k or lower,use the hydraulic roller.over 6k you should consider a solid cam.Big blocks need a few goodies to live at higher rpm s

If there are engine builds with peanut heads making over 500hp why would I swap my 781's out for $2000 aluminums ? without a ballanced engine over 6000 it wont live long so I will keep it under , 11.6 is the goal but dont plan only racing want to have a fun on the street as well

jumbo2 10-14-2012 01:39 PM

Quote:

Originally Posted by F-BIRD'88 (Post 1599038)
You next best low budget choie is a good BBC mechanical flat tappet cam and lifters.
They work real good too.

The BBC street hyd rollers tend to give up the ghost at 5500ish rpm some as soon as 5200
some 5800. most all al giveing up power by 6000rpm.

You do not want that with nitrous. The new improved limited plunger travel hyd roller lifters Crane etc.
are pricey and require a real good cam lobe design (Crane Hyd roller) and big springs.
now you are into money.

a lot of people that have been down this road end up running a solid mechanical roller lifter and more spring
on their Hyd roller cam to get the nessessary rpm capability . (very small cold lash setting .001" to .004")
Why not get get the right mechanical street roller cam and mechanical roller lifters in the first place?

Do you got enough money to do this twice- three times?

The mech street roller is the good deal ..... net cost and far superior performance in a BBC.
The XR mechanical street roller K kits are hard to beat.

the motor came with a comp 274 hyd flat tappet cam and lifters , I got the roller lifters for almost nothing so my budget allows for a roller cam or flat tappet cam/lifter combo , from all I have read about BBC rounding cam lobes off I cant see how a hyd roller isnt better than a hyd flat tappet

jumbo2 10-14-2012 01:42 PM

XR mechanical K kit if over a grand , that doesnt sound to cost efective to me ?

vinniekq2 10-14-2012 01:49 PM

Unless you put your peanut heads on a flow bench,you really have no idea how many horses you can get from your engine.Porting your peanut heads is not money well spent.You mentioned using 3.73 gears,so you need lower rpm/torque engine.If you use a big cam to make high rpm horse power then your peanut heads will hold you back.
when you have flow numbers you can determine HP potential,,,

jumbo2 10-14-2012 01:56 PM

Quote:

Originally Posted by vinniekq2 (Post 1599051)
Unless you put your peanut heads on a flow bench,you really have no idea how many horses you can get from your engine.Porting your peanut heads is not money well spent.You mentioned using 3.73 gears,so you need lower rpm/torque engine.If you use a big cam to make high rpm horse power then your peanut heads will hold you back.
when you have flow numbers you can determine HP potential,,,

Maybe I didnt make things clear im not running peanut heads , If peanut heads can make 500hp why wouldn;t my 781's ? I have a good set of 781's and am capable of cleaning them up and even some port polish work

jumbo2 10-14-2012 02:04 PM

[QUOTE=F-BIRD'88;1599050]The K-11-770-8 and K11-771-8 kit is $900.

900 plus tax is $1000 in my books wich is not in my budget , Like I stated I can buy a hyd roller or replace the comp 274 with something else or run the 274 flat tappet , I plan on doing alot of street driving and the odd race track pass

vinniekq2 10-14-2012 02:36 PM

781s /peanut heads/vic junior aluminum,???w/e head you use,doesnt matter,flow test them to see what power you can make,,,,other wise you are guessing.The number 500 is just a number for bench racing.lots of lower h p cars,,,IE honda,, or other little 4 bangers go faster than BB chevys for a reason.

RPM/gear matching,,weight/hookup,,,are the things you need to consider.
again,my 80 Camaro ran 11.9 with stock LS-5 specs,using z-55 cam,830 holley,vic oval port,hooker street headers,turbo 400, 219/188s. If you want to go faster,improve on that package,better heads would make the biggest difference.

vinniekq2 10-14-2012 07:43 PM

Information I found is,The oval port heads flow 270 cfm in the intake side and 190 cfm on the exhaust side,Thats 70% on the exhaust side so a split pattern camshaft would be needed.If you really know your engines you could make 590 horse power or probably a lot less with all the right parts.Thats using a .600 lift cam.
the peanut ports flow 225/160 for the 156 heads and 235/150-165 for the 236 peanut heads,so 450 horse power maybe,,,not worth using in a performance car.

TheRacerrick 10-16-2012 07:32 AM

With your compression a custom comp cam on a steel core with extreme marine lobes 3733 for exhaust 3475 for intake ground 112 +4 Use lunati 75820 beehive springs set them .060 from coil bind it won't float till 6500


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