Calling Harold from downunder. [Archive] - Chevelle Tech

: Calling Harold from downunder.


tuffss
Oct 12th, 07, 5:30 PM
Hi Harold
It was suggested by other team members that I contact you regarding camshaft selection for my 496 bbc, understanding that you are a busy man & possibly hard to catch up to with the time difference here in Australia I thought maybe you could suggest a cam for my project on this site.
My engine has already been dynoed & did not produce thrilling results she currently has a big Crane solid flat tappet p/no 134771 with 272-280@50 & 659-679 lift with a 110 l/s, 11-1 C/R with SRP 18cc pistons, Merlin III alloy cylinder heads 310cc runners & 114cc chamber with extra porting a good old Victor Jnr & a 950 AED modified Holley, she's not going in a Chevelle but instead a 68 Camaro weighing with driver approx 3300Ib it has a powerglide with a possible 4500 - 4800 convertor & 9" with 4.11's & 27" tall tyres (275/60-15). The engine dyno resulted in 600 hp @ 6000 & 567 ftIb @ 5250 as some on this site suggested this engine could possibly pick up 20 - 40 ftIb from a cam with 10-15 degrees less duration & naturally finish around the 4500 mark where I expected it would. We do have some fairly good fuel available here in Australia with Premium unleaded having 98 octane & some service station outlets having 100 octane hence the reason I never had any fuel issues on the dyno using 98 octane but then again with the camshaft that I currently have the engine would be bleeding off a bit of cylinder pressure being lucky to see 10-1 let alone 11-1 as specified.
This car is primarily a street driven car but with the occasional trip to the strip & the odd traffic light assault. Harold if it is of any assistance the following are some flow figures from the porting work on the Merlin III's.
Intake
.450 - 269.1 cfm
.500 - 289.1 cfm
.550 - 306.1 cfm
.600 - 321.6 cfm
.065 - 334.2 cfm
.070 - 342.9 cfm
.075 - 350.1 cfm
Exhaust
.450 - 186.2 cfm w/69.2% variance
.500 - 202.2 cfm w/70.0% " "
.550 - 216.5 cfm w/70.6% " "
.600 - 230.7 cfm w/71.7% " "
.650 - 241.4 cfm w/72.2% " "
.700 - 251.2 cfm w/73.3% " "
.750 - 256.0 cfm w/73.1% " "

I still want a solid flat tappet cam so any recommendation would be greatly appreciated again thanks for your input.

tuffss
Oct 29th, 07, 6:59 AM
Hi Harold
Any chance you maybe able to look this one over I can imagine you day is fairly hectic but your opinion would be much appreciated.

Many thanks
Tuffss

thehornworks
Oct 30th, 07, 9:37 PM
bump up , for ya

dacaman12
Oct 31st, 07, 7:06 PM
Harold usually sticks to the performance section, but I'll see what he says the next time I speak to him.

tuffss
Nov 1st, 07, 7:19 AM
Thanks Guy's for your help, Harold got back to me today with a cam suggestion which is one of his Ultradyne cams p/no BB296/304, I assume that this cam is now what Lunati call p/no 402B1LUN as the specs look identical but I will call Steve at Lunati to confirm unless anyone here knows if this is correct.
Thanks again guy's
Cheers Tuffss.