• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Need to change the Purple 509?

R

RRcrazy

Well-Known Member
Local time
11:24 PM
Joined
Mar 22, 2012
Messages
50
Reaction score
12
Location
Ohio
Ok so here is the issue., 1970 RR 4 speed with 3.23 rear. Car has no low end at all. Previous owner had engine built and put a 509 purple 292/299 in it. I'm thinking I need to change the cam for sure and maybe the rear end too .....let me know what you think. Here is the info:

383 .040 over
3 angle valve job
Wiseco pistons
908 open chamber heads
Motor Balanced
509 292/299 cam
Elderbrock Torquer Intake
Holley 750 Double Pumper
4 speed
3.23 rear end

Looking for a good combo that will make this car fun.

Thanks.
 
It wont have bottom end with that cam, especially with low compression.
If you like the seat of your pants torque, and don't plan on revving past lets say 5000 rpm, then you should take it out for sure.
Go get yourself a new "modern grind" camshaft for your street cruiser, that works with lower comp and limited to lower RPM range. You probably have a little more wiggle room at the lower end with your manual trans, but I think something that works from 1500 to 5000 should do it. Also, if you have a few extra nickles to rub together, you could benefit by using a dual plane intake to help the bottom end grunt your looking for. 3.23:1 gears are on the steep side for a street bruiser, but will let you run the freeway without revving much. I personally like the 3.91:1 ratio for street applications when I don't plan on being out on the freeway much. My ride has 4.10:1 ratio, but it's a street strip bracket car. If I didn't plan on driving around as much as I would like, Id'e have 4.30:1 gears out back!
I'm sure others will chime in...
 
The .509 is a good cam but as mentioned, not with tall gears and low compression. The easy fix is a smaller cam. Get some cylinder pressure in that engine and it will like it!
 
I'm curious why the torker 2? It is more of a top end manifold i think. My RPM air gap is very nice and gives good low end performance, I have had Torker 2's and know how the results were.
 
Not sure why previous owner put on the torker intake. just seems like he was trying for high RPM's but not sure....but the combo isnt working. I have to double clutch @ 3K just to get this thing rolling.....
 
RRcrazy said:
Ok so here is the issue., 1970 RR 4 speed with 3.23 rear. Car has no low end at all. Previous owner had engine built and put a 509 purple 292/299 in it. I'm thinking I need to change the cam for sure and maybe the rear end too .....let me know what you think. Here is the info:

383 .040 over
3 angle valve job
Wiseco pistons
908 open chamber heads
Motor Balanced
509 292/299 cam
Elderbrock Torquer Intake
Holley 750 Double Pumper
4 speed
3.23 rear end

Looking for a good combo that will make this car fun.

Thanks.
Click to expand...
take that cam and throw in the deepest river you can find. 383's don't make torque and hot hydraulics make that matter even worse.
 
my 383 all stock could roast the ties pretty good, I would consider getting back to as close to stock as possible. Like meep said get a smaller cam the stock one or near it. I would get a aluminum version of the stock manifold too keep the 750 and go from there would be a very nice street car with good low end. That torker 2 has just taken all the low end out of the equation. Good luck ;)
 
Your build up is mismatched but would benefit from as much timing as the motor will take, plus 4.10 to 4.30 gears and a newer design manifold.

Or remove the cam for something better like a Mr. SIXPACK design and a set of 3.55-3.91's

Many years ago I had a 509 in my 72 8.1 400 with a torker and 750 D.P. with every gear from 3.55 to 4.56.
Got the car to run a best of 13.19 but my distributor had 22 initial and 38 total all in by 2200 and I know how to tune a Holley very well.
 
If you want to cruise with the 3.23 and get some type of fuel economy, why not go with an RV type cam. Granted, not much above 5000, but a lot of grunt down low and keeping the R's down makes engine life go up.
 
i had the same problem. i have a 383 w/ 509 purple cam, 3500 stall convertor, 391 rear, torker II intake. No bottom end torque.
I recently changed my intake to a rpm dual plane, changed out the 750 dbl pumper for a holley 770 street avenger w/electric choke.
I haven't run it yet, but will let you know. If I am not happy, I plan on swapping out the cam, and lower stall convertor.
 
Thanks, Djais1801

Let me know how it goes. Hopefully it works for you. Since your running 391 gears and were still having low end problems.....changing rear ends to help looks like it wont work. I'm going to pull the cam and change the manifold.

Anyone have a good combo for a cam and manifold for a 383 4 speed with 3.23 rear.

Thanks.
 
All the recommendations and no one has asked what the static compression ratio is or what the cam id timed at or even what the cranking PSI is?? Without this info, you are in the dark. I've have plenty of experience with the old 509 cam in low deck engines and they work pretty good but they usually need to be advanced some when installed. Advancing a cam doesn't make any more power but brings the power in at a lower rpm. If you don't know what the builder set the cam at, you need to find out. Incorrect cam timing is the biggest cause of poor performance. The question I have is....does the engine 'turn on' above 3000 rpm and put on a pretty good show of power? Also, what is your ignition timing? If you do have low cranking PSI, then the engine will most likely like more ignition timing too.
 
Cranky said:
All the recommendations and no one has asked what the static compression ratio is or what the cam id timed at or even what the cranking PSI is?? Without this info, you are in the dark. I've have plenty of experience with the old 509 cam in low deck engines and they work pretty good but they usually need to be advanced some when installed. Advancing a cam doesn't make any more power but brings the power in at a lower rpm. If you don't know what the builder set the cam at, you need to find out. Incorrect cam timing is the biggest cause of poor performance. The question I have is....does the engine 'turn on' above 3000 rpm and put on a pretty good show of power? Also, what is your ignition timing? If you do have low cranking PSI, then the engine will most likely like more ignition timing too.
Click to expand...


Exactly right, and I was implying that by suggesting the smaller cam. I ran an old torker (not torker II) on a 383 and it was great, but like you said, give it the compression it wants with a big cam.
 
You must log in or register to reply here.

Similar threads

67coronetman
Hydraulic cam comparable to the 292-509 purple shaft.
Replies
10
Views
3K
PRHeads
PRHeads
64Orange
  • Locked
SOLD 1964 Plymouth Sport Fury project
Replies
2
Views
2K
64Orange
64Orange
uk-maxie
MP purple cam and lifter recommended preload?
2
Replies
24
Views
3K
oldkimmer
O
C
New 440 build issues
14 15 16
Replies
307
Views
21K
chermik1999
C
Gunner1
Looking for how to tune my Caltracs info.
Replies
10
Views
1K
Gunner1
Gunner1
Auto Transport Service
Back
Top