• 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
cam selection
#1
Hi DOC and members, I liked the spec's on the cam DOC recommended, and also sent info to comp cams for recommendations. Andrew would only go to a 32-241-4 without knowing my compression. I'm not sure what mine has because I have heads #'s for a 71 CJ and a 72 block 8.6, 9.0 or 10.1-1.Dodgy
found old cam spec's.. Erson E220421. 541lift 298 duration. Also said needs headers.. (had been removed), compression (which I don't know) and gears (which not sure)...Huh
[Image: 1_30_09_13_10_12_32.png]
Alan L
  Reply
#2
Open chamber heads or closed chamber?
Do pistons have a dish or are they flat? If flat how much deck clearance?
I can throw out a gusess but you can also assemble/mock up the shorblock and take some measurements
[Image: mustangnight010.jpg]
1972 Mustang Convertible 351C 4V
1966 Ford Galaxie 7 litre-4speed

Jorge
  Reply
#3
(10-20-2010, 05:52 PM)jorgem2 Wrote: Open chamber heads or closed chamber?
Do pistons have a dish or are they flat? If flat how much deck clearance?
I can throw out a gusess but you can also assemble/mock up the shorblock and take some measurements

closed and flat


Attached Files
.jpg   002.JPG (Size: 206.82 KB / Downloads: 104)
.jpg   001.JPG (Size: 177.81 KB / Downloads: 102)
[Image: 1_30_09_13_10_12_32.png]
Alan L
  Reply
#4
Those are actually "open" chamber heads.

If the casting number is D1ZE-DA OR D1ZE-GA, they have the 75.4 combustion chambers which equates to an advertised compression ratio of 9.0 with the stock pistons.

Other than four bolt mains or two bolt mains, the blocks and stock pistons are essentially the same and have no difference in the compression ratio of the '71CJ and the '72 4Vs.

Hope this helps.


BT
Do the RIGHT thing.
  Reply
#5
(10-20-2010, 05:23 PM)not2old Wrote: Hi DOC and members, I liked the spec's on the cam DOC recommended, and also sent info to comp cams for recommendations. Andrew would only go to a 32-241-4 without knowing my compression. I'm not sure what mine has because I have heads #'s for a 71 CJ and a 72 block 8.6, 9.0 or 10.1-1.Dodgy
found old cam spec's.. Erson E220421. 541lift 298 duration. Also said needs headers.. (had been removed), compression (which I don't know) and gears (which not sure)...Huh

Hey Alan -

There's only a slight difference between the 241-4 and the 242-4. The 242-4 has a 218/224 duration at .050 and a .513/.520 lift. The 241-4 is slightly more tame with a 212/218 duration and a .487/.493 lift. Sounds like the cam that was in there was pretty radical. Remind me again - yours is a 351C-2V, right?

Doc
Doc

[Image: 6y14ea.jpg]

Project started 8-7-10
Completed: All new suspension, rebuilt 351C H Code bored .030 over with mild cam and intake, new 3.50 TracLok, custom exhaust system
Current "mini-project": interior upgrade Undecided
  Reply
#6
As Cobra said get the numbers off of them and I have a really good reference source for all ford part numbers. I will be happy to look up what they started out life as anyways. Can also look up the block number also and if you can get me a part number from your pistons will look that up as well.
  Reply
#7
(10-20-2010, 08:32 PM)73vertproject Wrote:
(10-20-2010, 05:23 PM)not2old Wrote: Hi DOC and members, I liked the spec's on the cam DOC recommended, and also sent info to comp cams for recommendations. Andrew would only go to a 32-241-4 without knowing my compression. I'm not sure what mine has because I have heads #'s for a 71 CJ and a 72 block 8.6, 9.0 or 10.1-1.Dodgy
found old cam spec's.. Erson E220421. 541lift 298 duration. Also said needs headers.. (had been removed), compression (which I don't know) and gears (which not sure)...Huh

Hey Alan -

There's only a slight difference between the 241-4 and the 242-4. The 242-4 has a 218/224 duration at .050 and a .513/.520 lift. The 241-4 is slightly more tame with a 212/218 duration and a .487/.493 lift. Sounds like the cam that was in there was pretty radical. Remind me again - yours is a 351C-2V, right?

Doc

Thanks for the comback DOC. Mine is a 351C-4V
Agains thanks to everyone, and here are some #'s Heads are D1ZE-DA
and Pistons are L2379 .030. Block is D2AE-CA
[Image: 1_30_09_13_10_12_32.png]
Alan L
  Reply
#8
The number on the piston appears to be from TRW which is now Speed Pro. That piston was supposedly designed as a direct replacement for the stock piston in Super Stock racing. The advantage is that it is of the forged variety.

As previously noted, with your open chamber heads the compression ratio should be around 9.0.

Hope this helps.

BT
Do the RIGHT thing.
  Reply
#9
D1ZE-DA
71-72 351CJ

71 351C
Valves 2.19, 1.71

73-76cc (Open chamber)

In port 2.50 x 1.75

Ex port 2.00 x 1.74

Pistons
L2379F 30 pistons have a volume of -1.5cc. With 63cc heads the compression is 10.22 to 1 but only 8.9 to 1 with 76.2 cc heads
  Reply
#10
As previously inferred, since that piston is a Super Stock replacement, I am pretty sure that it mirrors the compression ratio of your stock piston which would be 9.0 with the 75.4 cc head.

As to rear end ratio, there are simple means to determine the ratio both with the pumpkin "in" and "out" of the car.

1. If the rear end is still in the car, you will need to jack up the rear, maybe by using jack stands. Mark one of the rear tires with a piece of chalk at the 12 o'clock position. You will also need to put a horizontal line on the drive shaft. Rotate the tire one full revolution while watching how many times the drive shaft goes around. If it goes around 3 1/2 times (and you have a posi in the rear), that would denote a 3.50:1 gear. If it goes around 3 3/4 times (again with a posi), you probably have something like a 3.73:1 gear.

If you do not have a posi, all you have to do is multiply the revolutions by 2. For example, if the driveshaft rotates 1 1/2 times when you you make one revolution with the tire, you multiply that by 2 which will yield a 3.00:1 open rear gear.

2. If the rear end is out of the car, you simply have to count the teeth on the ring gear and the pinion gear and divide the pinion gear number into the ring gear number.

For example, if your ring gear has 37 teeth and your pinion gear has 9 teeth, the result would be a 4.11:1 gear ratio.

If the gears are still in the housing, you can usually count the respective teeth by placing a horizontal chalk mark on the ring gear and rotating the gear to determine the number. You would do the same thing on the pinion gear. Then do the division math as cited above.

Hope this helps!

BT
Do the RIGHT thing.
  Reply


Possibly Related Threads...
Thread Author Replies Views Last Post
  decide my new cam/ valvetrain set please Casperfast 15 658 12-08-2016, 10:42 AM
Last Post: Don C
  2V cam KT-69 23 1,086 11-02-2016, 10:27 AM
Last Post: Mikes73
  Going EFI-Need advice on fuel hose selection 4mm 23 1,407 08-30-2016, 03:47 PM
Last Post: jbojo
  351C Tear Down - Crank and Cam removal timsweet 20 1,063 08-16-2016, 06:20 PM
Last Post: timsweet
  Radiator Selection kcmash 9 476 08-11-2016, 09:55 AM
Last Post: Mister 4x4
  Clutch Selection- Really Need Your Advice! 4mm 13 1,118 04-04-2016, 07:06 PM
Last Post: secluff
  How to check cam specs without a card? scgamecock 11 894 04-03-2016, 08:15 PM
Last Post: barnett468
  351c cam choice. Odmark 56 3,775 02-26-2016, 09:42 PM
Last Post: MeZapU



Users browsing this thread: 1 Guest(s)