[HPseeker]

UDHAROLD ,BBC gurus cam advise ,please

I am refreshing my motor and want to try another camshaft,please help.I want to go in to the 11's .

Motor combo :

Tall deck Big Block 427 @ .030 over
10.2:1 cr
990 RECTANGULAR PORT heads 2.25in/1.88 ex
crane gold 1.7 rolller rockers
PERFORMER RPM intake
Holley 850
1 3/4" primary tubes headers
th 350 ,3500 converter
4.56 rear with 31" tall x 16.5 wide tires
Comp Cams XS282S
@ .050 244/ 252 590/598 lift 282/290

I will like to run again a mechanical flattappet cam .Thanks in advance Sir .

 

[HPseeker]

Should I keep the the same cam ?

 

[HPseeker]

anyone ?

 

[BORDERT]

I don't think just changing the cam will do what you want.I think the setup you have will work just fine ,but the MPH seems slower than it should be for your combo.Do you have adequate fuel supply at the topend and/or is the timing too advanced ?Your mph should be about 112-115 and then your in the 11's.

 

[BORDERT]

I don't think just changing the cam will do what you want.I think the setup you have will work just fine ,but the MPH seems slower than it should be for your combo.Do you have adequate fuel supply at the topend and/or is the timing too advanced ?Your mph should be about 112-115 and then your in the 11's.( Just another thought but your convertor may have excessive slippage and that is also losing MPH at the top)

 

[GRN69CHV]

Cam is not your problem, rear end ratio is wrong. Based on your 31" tire size and running a Rec port, solid cam 427 motor, you need to cross the finish line at about 6500 RPM. With a 4.56 gear, you are only running about 5500 - 5600 at 107.79 MPH (based on 5% converter slip). You need a 5.13 gear in there. 5.13's will get you through the traps at 115 MPH at 6500 RPM so you will be close to peak power at the top end. THe way you have it set up with the 4.56's, you are probably down close to 100HP at the top from where your true peak HP actually occurs. Would be great for a 3/8 mile run, but not for a 1/4 mile run.

Get some 5.13's in there and don't be afraid to run it.

 

[Troy70SS]

Try running some 28" or 29" tall tires and see how she does. That should put you where you need to be. I have the same problem. I have 28" tall tires and I need 26" tires with my 373's.

Troy.

 

[HPseeker]

Bordert, I have a -8an line from tank to carb with a mechanical Carter 172gph pump ,the timing it is lock 42 degrees , I did retard it to 36 degrees but the best mph was at 42 ,next time I will try the timing at 32 degrees and start from there ,about the converter it is a TCI 10" #24100 ,How the converter is tested for slippage ?Grn69chv ,I did try a 4.88 before with no better results ,the MPH was slower than the 4.56 ,I even got some advise from other TC member to try a 4.10 ratio,I will try the smaller tire as mentioned by Troy .

I am asking Harold for a cam because everyone is running Harolds cams with EXCELLENTS results ,he advise me before but was a roller cam and I can only buy a poor man's roller a "SOLID FLAT TAPPED" cam

 

[UDHarold]

Javier,

With the 3500 SS converter and the 4.56s, if you don't mind a rough racy-car idle, use the Lunati 402A6LUN. This is the 107 LSA version of my 288/296F, the most famous SBC/BBC solid lifter cam I ever had. It is a ferocious bracket cam, and the only one I sold until someone wanted one with a much lower idle( The Lunati 402A7LUN).
Both cams are 288/296 at .020, 255/263 at .050, .612"/.630" gross valve lift. A 427+.030 at 10.2:1 should be capable of 550 to 570 BHP about 6400 or so. If you run 140 lbs on the seat and about 340 lbs open, it will rev over 7500 with your fuel system. A 12.5:1 CR would move the peak power up to around 6800.

Bad weather is forcing me off, so this may be the only reply today.

UDHarold

PS---I have seen the decal, and if things work out OK, by the PRI show I should be back in business. I will have an improved cam for this by January.....

 

[HPseeker]

Thanks Harold for the advise ,what phone # to order the cam ?

The goods news here are you getting back in to business ,CONGRATS HAROLD BEST OF LUCK

 

[UDHarold]

Javier,

If you want to buy the current one, call Steve at 662-892-1526.
I can't or won't publish my number until PRI. BTW, I don't have it yet.....
I'm working on a brochure right now, to have Kinko print, for PRI.

Now, don't anybody ask me for more information, because that's all I will say, until PRI...

UDHarold

 

[Mike McMasters]

Glad to hear it harold!! just in time for my new 468 build. i already bought a 402a3 but it will not be a problem to send it back.

congats again!!:beers:

mike