[Gary D]

I am rebuilding the top end of a fresh 1971 455. I have a set of SD Performance CNC ported #96 heads. They flow at 260 cfm +
The rest of my combo is a 67 A-body hdtp 2 door. 3:42's out back in an Oldsmobile "O" axle (you know the wanna be 12 bolt with the 10 bolt ring.) I think it is an 8.5. In front of that is a TH400 with a shift kit and a 2500 stall converter.
Exhaust is exited by a set of Dougs D port headers followed by a full 2 1/2" system with Flowmaster 40's in the middle and tail pipes to the end.
Current carb is an awesome 76 800 Q-jet. Runs great. Sits on top of a Performer RPM with a 1" spacer. (yes the hood closes but the torque pushes the air cleaner top to the hood, there is a witness mark)
BFG's all around on Appliance Wheels (old school)
24" tall 60 series
Best run cool night at sea level is 13.041 at 104 mph

I am trying to choose a cam that will best fit street/strip combo.

I am leaning towards a Ram Air IV cam, but cannot decide beteween Melling's, Comps, Crower's or Lunati's. They have all tweaked the original except for Melling.
I am hoping for a low 12's or high 11's after this swap
What do you think?

[David Jones]

Something is definitely choking it now with an mph of 104.

[Gary D]

Ya, The cam I am running now which was picked by another person seems to fall on its face about 1/2 way through 3rd gear. Runs hard through 2nd at 85 mph timed at 8.39
That is why I am going to do a cam change and posted this question about cams

[David Jones]

Is your fuel system up to it?
Describe what "falling on it's face" feels like. I wouldn't be surprised if what you are feeling isn't the little bowl in your Qjet running out of fuel. My 400 would suck the float bowl dry before I added an electric pusher pump to help the mechanical. If the cam were "falling on it's face" it would be doing it in 1st and 2nd gears also.

[rustedgoat]

Give SD Performance a call. Tell them your intentions and combo they'll steer you in the right direction. Do you have any idea what cam is in there now?

[Gary D]

I am running a good mechanical pump with a non socked 3/8 line pushing through a Summit wafer style filter and a large .149 dia. seat which I did notice a difference when I went to that size and was also told by SD that I should be fine into the 11's if everything was as I told them with about this combo. I have not ruled out a pusher pump, I have just not pursued it yet.
As far as the cam goes it is basically a Comp XE284 with 1.5 Harland Sharp rockers

[ta man]

Those times are they with those heads or previous times.If SD did those heads call them for a cam>run as much lift as your springs will allow.I'd definately install a good fuel pump like a Mallory 140.This just for starters.To run elevens you'll need a good fuel supply,excellant traction,decent 60ft like a 1.6 or 1.7.You may need to upgrade your fuel lines>I'm running 114.59mph with a Mallory 140 with stock lines but I'm upgrading to larger lines and fittings this year.You may want to have 3 inch exhaust off the headers back to the mufflers.Think about upgrading your torque convertor to give you more jump out of the hole and better coupling down the track.If that 2500 is a generic brand you may be blowing through it down the track and losing mph.It took me 6 years to get my car from 14.2 to 11.88.I learned alot you can do it all at once or little by little.You have the basics > a 455 ,good heads,3.42 gears now just set up everything else.Good luck.

[Gary D]

These times I am giving are from my current combo of a 1971 455 .030 over and set of #96 heads also, just not the ones from SD yet. Rest of the combo is in my original post. With the street tires I run I am launching at about 2400 with a 1.9 @ 60 ft. time. Not bad for TA's. Short ones at that!
I am going address the fuel issue with a pusher, going to add a Mezeire electric water pump, March's u/s crank pulley, Spal Dual electric fans, Performer RPM intake ported to match SD's ported 260+ CFM #96 heads and am moving the alternator to the right side down low so I can keep the power steering in the stock position. I just want some opinons on a great cam for my combo. I have everything I just listed. Just need to make a decision on a cam. I should be around 9:5 on my compression ratio. I know a RAIV cam would run hard with this setup. I just do not know which version I like the best.

[Kyflier]

Sent you apm

[Gary D]

what is an APM

[Kyflier]

A private message, I have a Melling SPC-8 cam and lifters for sale, has about a 100 miles on it.

[WDCreech]

Originally Posted by garysredrod

I am running a good mechanical pump with a non socked 3/8 line pushing through a Summit wafer style filter and a large .149 dia. seat which I did notice a difference when I went to that size and was also told by SD that I should be fine into the 11's if everything was as I told them with about this combo. I have not ruled out a pusher pump, I have just not pursued it yet.
As far as the cam goes it is basically a Comp XE284 with 1.5 Harland Sharp rockers

The problem is not your cam! As David Jones said, your fuel pump can't keep up with the engine at full throttle. When I drove my 461 cu in '63 LeMans on the street, I had the same problem. I put two diaphram type electric pumps, back at the tank, with a switch to turn them on when needed. It completely solved the problem. The mechanical pump has no trouble pulling through a diaphram pump, but would through a vane, if it were shut off, so you don't need to run the diaphram pump, for normal driving.

[David Jones]

Before you do anything else upgrade your fuel system. For my engine a small Carter back at the tank worked. I run it on a switch (under the dash, out of sight) and don't use it all the time. But the float bowl stays full with the electric added to the mix. The rest of my fuel system is completely stock. I picked up 4mph...........

With a 240-246 cam? You'll have your 12 second car.

[Gary D]

I want to thank all of you for your expert help in this matter. I will pursue the fuel issue first and see how my times change. I think our track opens in March!
Then I really want to change out to the rest of what I have aquired for this build and the cam change to a Melling RAIV. I am hoping to see an even bigger improvement!

[Gary D]

Do you have a recommended pump for this application that does not break the bank?
I notced you said 2 pumps! Were you running the mechanical up front with the 2 you mentioned in the rear? Total of 3 pumps for racing and only needed 1 for street driving.

[David Jones]

I run one little Carter. Cost less than $100. You'll also need some sort of filter before the electric pump. I used a small RobbMc. None of it is permanently mounted.
http://forums.maxperformanceinc.com/...arter+electric
Since I did the original install I have dumped the Fram filter and now simply have a 40 micron (?) inline RobbMc filter before the electric pump and an AC Delco filter in the snout of my Qjet.

[WDCreech]

Originally Posted by garysredrod

Do you have a recommended pump for this application that does not break the bank?
I notced you said 2 pumps! Were you running the mechanical up front with the 2 you mentioned in the rear? Total of 3 pumps for racing and only needed 1 for street driving.

I assume that this post was addressed to me. Yes, I ran the mechanical pump on the engine, with two pumps at the tank. I ran this combo on two different engines. First was a .030" over 389 with dual quads, the second was a stroked 428 with a 1000 cfm Thermoquad. I think the electric pumps were Stewart Warner, but not sure. It's been over forty years.

[Gary D]

Originally Posted by WDCreech

I assume that this post was addressed to me. Yes, I ran the mechanical pump on the engine, with two pumps at the tank. I ran this combo on two different engines. First was a .030" over 389 with dual quads, the second was a stroked 428 with a 1000 cfm Thermoquad. I think the electric pumps were Stewart Warner, but not sure. It's been over forty years.

Yes this was directed to you Bill. I am new at this format of trouble shooting and this forum. I was on Summits site and they do not show a electric diaphram pump. I like the idea of not having to run it unless I need it. Thanks again for your help and Davids also.

[David Jones]

I believe the XE284 you have is a little "more" cam than a Melling SPC-8 RAIV you want.

[Gary D]

Originally Posted by David Jones

I believe the XE284 you have is a little "more" cam than a Melling SPC-8 RAIV you want.

Hi Dave, I know it looks like I am nuts to do the switch, but I am not exactly in a hurry. I am going to try the fuel upgrade first and then move on to the cam and heads. I am running a modified XE284 it has about 2 degrees less duration on the exhaust side. It was hand picked by lobes by a friend not realizing it was so close to a catalog cam and cost an extra 100.00 being custom. It also was ground at a 106' c/l . Back to your question. I have been running 1.50 ratio rockers with the current combo and will be running 1.65 with the RAIV cam. I know it will be just a little more lift, but at the same time I will be getting more duration. I think with what I am going to do in total (refer to an earlier post) will make a big difference in how this Goat responds when the pedal hits the floor! Thanks for your input.