Ford Muscle Cars Tech Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
6,662 Posts
Discussion Starter #1
Looking for some opinions on camshafts.Iam currently running a 68 302 with home ported 69 heads,weiand xcellerator intake,650 holley DP,long tube 1 5/8 headers,flat top pistons,although I don't know the exact compression and a 4-speed and 4.11 gears.The cam I have in it now is an older Comp Cams Magnum 292 which has [email protected] .050 and .518L .The car works pretty decent ran a 13.69 at100.94 in the summer heat but I have been advised a cam with less duration would work better.N2O Mike recommended a COMP cams extreme energy 268H which has specs of 224 and 230 [email protected] and .509 and .512L.The guy on the help line recommended the next cam up the XE-274 which has 230 and 236 [email protected] and .520 and .523L All three of these cams have 110 degree lobe centrelines.I certainly respect Mikes opinion as he has a very quick car that is similiar to mine in some ways and don't doubt what he is saying but was just looking for some more opinions.By the way the car wieghs about 3300 with me in it and is not a daily driver.
 

·
Registered
Joined
·
231 Posts
Are your heads ported 69 351 Windsor heads or 302 heads and do you run with open headers?
 

·
Registered
Joined
·
6,662 Posts
Discussion Starter #3
My heads are 69 302s with guideplates and a home port job.They wouldn't have been my first choice but they came with the engine and already had the guideplates and screw in studs so I used them.I run open headers at the track but on the street I have a full exhaust system 2 1/2 inch with flowtech afterburner mufflers.
 

·
Registered
Joined
·
125 Posts
I'm running the Comp 270H in my 347. Very good idle and very strong bottom end. The only problem in the 347 is that it ran out of steam at 5700 on the chassis dyno and went lean with a 750 DP, probably would work good in your block and head combo.
 

·
Registered
Joined
·
231 Posts
If you want a cam that works well when your headers are open and you want power from around 3800 or 4000 to over 6500 RPM the cam you've got will work fine. With your limited headflow you need more cam to make the same power, than would an engine with excellent flowing heads. Personally I would switch to a solid and run a 294S from Comp Cams(248-248 .560-.560 110 l/s +4) It would work in the same RPM range but would make better low and midrange torque and slightly more top end power and you'ld have no problem running well over 7000 RPM. Have you considered switching your intake from a Wieand Accelerator to a Vic JR? The Vic Jr will make more power everywhere above 3000 RPM than the intake you're running now.

<font size=-1>[ This Message was edited by: mach1morgan on 3/25/02 5:36am ]</font>
 

·
Registered
Joined
·
669 Posts
i have a comp cams 294s in my 347 i have dart snr's,quad webers,1 3/4 headers,it goes balistic around 3200 and i havent had enough room on the road or big enough balls to go any harder than 5500 before i change gears,superb cam
i recommend it(with the correct engine build up of course)
 

·
Registered
Joined
·
7,470 Posts
Well, Frdnut is only dealing with 302 ci, and as we all know, a larger engine needs more cam to turn the same rpm's as a smaller engine. Plus, he's dealing with a set of stock (mildly ported) head castings. The rest of his engine combination is spec'd for a shiftpoint around 6000-6300 rpm. In addition, the compression ratio isn't that high with the 69' heads.

If he was after MAX power at high rpm, with little regards to how the engine ran in the low-end and midrange... and had the intake, carb, heads, exhaust, etc to go along with it, one of these 240'ish cams would be great.

We're dealing with a street/strip 302 with a stock set of heads that needs to pull double duty. Unless the heads have some serious work, they won't be good over 5800 rpm anyway. The rest of the engine wants a max rpm of around 6300. The right cam for this engine would produce the most power UNDER THE CURVE through it's entire rev range.

This is where the XE268H comes in. The rest of the engine won't really be able to take advantage of anything larger than this 224/230 @ 0.050" cam. This cam will pull cleanly from low rpm, and come on STRONG at 3000 rpm. Those 240'ish cams won't start working in a 302 until at least 4000 rpm, and by that time, the heads are about all done. The huge cam will make it a dog taking off, and the small heads will choke it off on the top end. The car will be a complete 'dud'. The cam in my mustang only measures 236 @ 0.050" on the intake, and it doesn't start to pull HARD until 4000-4500 rpm.... and it's a solid. The hydraulic equivalent would only measure around 232 @ 0.050".

I used a 224/236 @ 0.050" solid cam in my car at one time with a moderately ported set of stock heads in a generic 289, and it ran 12.74 in the 1/4 mile.... making GOOD power from 3-6.3k rpm. This was with a Torker intake and 650DP.

Good Luck!
 

·
Registered
Joined
·
6,662 Posts
Discussion Starter #8
Just to throw in another curve,if I throw this engine back in my 63 Falcon will this cam (XE-26
work well with a c-4 with a 2800 stall and 4.11s?
 

·
Registered
Joined
·
2,129 Posts
I run a comp cams grind

540 lift intake @ .220 duration
566 lift exhaust @ .224 duration

The mechanic doing the work on my car recommended it for low end torque and top end power. I am not a cam guru, but thought I would share this with you.
 

·
Registered
Joined
·
2,129 Posts
In addtion I just made my first pass at the strip, this thing is puttin the horses out, it ran a 13.88 at 107.5, that was all 4th gear, the first 3 gears were lift,pedal,lift,pedal,liftETC.ETC.ETC.
So that cam is doing its job at the top end.
 

·
Registered
Joined
·
231 Posts
Basically, it depends what you want from your car or engine. If it's lower et's and faster 1/4 mile speeds, I gaurantee a 294S in your car will run faster in the 1/4 than an XE268H will. But, if you want a more streetable engine with a broader power band and more low end torque and don't mind sacraficing some horsepower to get it, then Mike is right. The smaller cam will do that for you. Just don't expect to make the same HP that you were making with the 292H or would make with a 294S cam.
Something else to think about when dealing with 289 and 302 heads is that the exhaust ports on these heads respond to porting quite a bit better than the intake ports do. More often than not when these heads are ported you end up with an intake to exhaust flow balance of between 85% and 90%. If this is the case with your heads go with a single pattern cam as a dual pattern cam will be of no benefit. The extra exhaust duration will only serve to clip of the last bit of power stroke, which reduces torque slightly, and will create extra overlap which hurts streetablility, low end torque and throttle response.
 

·
Registered
Joined
·
6,662 Posts
Discussion Starter #13
The car has excellent manners the way it is now.It doesn't foul plugs,idles well,etc.I simply want the most I can get out of it ET wise,but keep in mind I limit the rpms to about 6000 as I'm unsure what rod bolts it has in it.N2O Mike can you give me more details on your combo that ran 12.74s, that would be almost a second quicker than I'm running now.

<font size=-1>[ This Message was edited by: frdnut on 3/26/02 11:00am ]</font>
 

·
Registered
Joined
·
7,470 Posts
A guy who used to be on the fordnatics mailing list, Christopher Schwartz, has a mustang with a 289 and Edelbrock RPM heads. The car was equipped with a large 254 @ 0.050" cam, and did alright. After switching to a cam similar to the XE268H, it's ET's actually improved. He said it ran better all the way around, and didn't need spun to 7000 rpm at the track to get good times.

Now, with plenty of compression and cylinder head, the bigger cams would have an advantage... but not in a 9:1 302 with mildly ported factory heads.

Good Luck!
 

·
Registered
Joined
·
231 Posts
On 2002-03-25 22:32, frdnut wrote:
The car has excellent manners the way it is now. It doesn't foul plugs,idles well,etc.I simply want the most I can get out of it ET wise, but keep in mind I limit the rpms to about 6000 as I'm unsure what rod bolts it has in it.
If you are limiting your engine to 6000 RPM you are wasting a lot of the HP potential of that cam you have in there and can most likely go smaller without losing much, if any performance. However, I think my plan of attack in your situation would be to pull the pan and see what pieces I had in the shortblock before I spent money changing parts to match a combo that I'm not really too sure about.
 
1 - 15 of 15 Posts
Top