250 build
- Thread starter 69stang_250
- Start date
Thats what I had planed. I am thinking I should be asymbling this thing in the next 3 weeks.
69stang_250":3fb4wfys said:
do the degreeing, C where U R. My assemblier usually uses an off set key to get the +4*.
This time he may use the extra keyways machined into the cam sprocket.
Will p/u the NAPA 'set' (only sold in individual pieces - $100) today.
Not sure where things will B till degreeing...
Enjoy!
It has a hole just like the original for a dowel pin to fit in the snout. I will post some pics up after I get back from the machine shop in a few hours.
Well in all honesty I have not seen anyone that has used the cam. I have been wanting to go for power and seeing what the 278 solid cam is doing, I figure the 280 should be a little similer. It may not be the greatest on the street when I get done, but I am after power and "shock" factor. The main reason I went with the 280 LSA 110 is talking to you guys.
Well, I think there are a lot more radical cams out there. But the way I am looking at it is that it should match well with the polished head, forged Pistons, and 4bbl carb. I know vacuum is gonna suck, but it should sound and run very good.
Nice!!
I really like the looks of the headers. I wish there was something similar for the 300 six.
It looks like the cam sheet calls for the cam to be installed 2 degrees advanced.
That's a good compromise between torque and horsepower
Just a quick note, I'm completing a 300 with ported heads that has a 288* advertised duration cam, 232* .050" with a 112* LSA for street use. It is not radical
You will like your cam!
I really like the looks of the headers. I wish there was something similar for the 300 six.
It looks like the cam sheet calls for the cam to be installed 2 degrees advanced.
That's a good compromise between torque and horsepower
Just a quick note, I'm completing a 300 with ported heads that has a 288* advertised duration cam, 232* .050" with a 112* LSA for street use. It is not radical
You will like your cam!
my 260 can still use an auto (hi stall converter only)
higher compression: check (U got)
manual only: ?
min of 3.50 rear gear: ?
It's all pretty esotiric 2 me.
Second life-time-build (if there's ever the $, I DO have the motor) I may go more radical & HP rather than tq.
Lotta learning to get there tho.
Think I'll stick w/ yous guys till school's out & I get past freshman anyway…
higher compression: check (U got)
manual only: ?
min of 3.50 rear gear: ?
It's all pretty esotiric 2 me.
Second life-time-build (if there's ever the $, I DO have the motor) I may go more radical & HP rather than tq.
Lotta learning to get there tho.
Think I'll stick w/ yous guys till school's out & I get past freshman anyway…
Pmuller- how do can you tell it calls for that advance on the cam card? I have been looking at it and it's killing me that I can not see what you see on the card lol And yes! Those headers are honestly the nicest set I have ever had my hands on!
Yes I think you are right on the radical part. I have been looking at it that these cams were made for a 200 inline 6 and the extra 50 cubes will make the cam act a little more tame than it would for a 200. That may be the wrong way to look at it, but it's kinda like comparing cams for all the Windsor engines I would think.
I will tell you guys I am so excited to get the engine together and see just how the car runs. I can honestly say that before I tore the car apart from a stop, I could spin the tires very easy and it would pull very hard. It may of helped that most of the car was stripped at that time lol but as long as I can get around 250-280 at the tires I will be happy as hell. If not, Im not gonna sweat it, but I will get this thing in the 13s at some point.
Yes I think you are right on the radical part. I have been looking at it that these cams were made for a 200 inline 6 and the extra 50 cubes will make the cam act a little more tame than it would for a 200. That may be the wrong way to look at it, but it's kinda like comparing cams for all the Windsor engines I would think.
I will tell you guys I am so excited to get the engine together and see just how the car runs. I can honestly say that before I tore the car apart from a stop, I could spin the tires very easy and it would pull very hard. It may of helped that most of the car was stripped at that time lol but as long as I can get around 250-280 at the tires I will be happy as hell. If not, Im not gonna sweat it, but I will get this thing in the 13s at some point.
Gene Fiore
Famous Member
You are right about the extra 50 cubes...a cam in a 250 will be much tamer than the same cam in a 200. I have the 278 solid lifter cam in my 250 and it seems fairly tame and easily idles around 700 rpm in gear...but it runs strong!
Gene- Your engine is the reason I even thought about going with the 280 cam. I figured if yours could send that maverick into the 14s I could get my mustang into the 13s with the AL head, slightly bigger cam, 4bbl carb, and good clutch.
They are classic inline headers.
69stang_250":2u177iq7 said:
Third line down "Lobe Center" says the intake and exhaust lobe centers are 110* apart from each other in camshaft degrees. This is also known as the Lobe Separation Angle. (LSA)
That means that if the cam was set neutral (Not advanced or retarded) the lobe centers would be equal distance from TDC, in this case 110* before TDC for the exhaust and 110* after TDC for the intake lobe. (crankshaft degrees)
Now if you look at the 4th line down "Centerline Timing Events" you will see the intake lobe center at 108* ATDC and the exhaust lobe center at 112* BTDC.
That is a 2 degree shift from being centered about TDC and the timing events now occur 2 degrees early or advanced.
This is an easy example because the intake lobes and the exhaust lobes are identical and the lobes themselves have symmetry about the centerline.
There are many cases where the opening side of the lobe has less duration than the closing side of the lobe and is called asymmetrical.
Then there are cases where the .006" to .050" lobe lift duration is much longer on the closing side to let the valve return to the seat gently.
This is why the lobe centers on the card were posted separately for the advertised and .050" lobe lift.
Gene Fiore
Famous Member
No doubt! I am curious to see how that cam works out!69stang_250":vytl2sha said:
69stang_250":14ow4e0g said:
Its all about relative engine size in the engine family, and
the 3 way formula dynamics Flow= Velocity times port area (Q=v.a,).
and mixture motion (SAE paddle wheel rpm at maximum torque).
engine size can vary from 75% to even 85% from the smallest to the largerst engine size in an engine family, so a 144 with a 280 cam will have radical chop, but a 250 with the same cam might have very little.
If you ever get the chance to drive a Shelby 306 hp or 271 hp 310 degree K code 289, then a 310 degree 351C 4V, the little 289 HP has a heap more lope. Or if you take even a 290 degree Boss 302 Aand compare it to the 290 degree 351 Boss, you'll get the idea. The bigger engine can swallow up the same duration without the whump whump whump creating a stalling issue. My mate Blair told me the best thing when he compared his 295 duration 505 Wade 325 cammed 351 4bbl to a 302 4-bbl Cleveland with the same heads, same carb, same headers. Roy, the engine builder, showed him how the short stroke 302 couldn't even hardly idle with the same cam. Holden used the nWade 325 as a road cam in the 5.0 Special performance 5 liter Commodores, and it idled fine. The difference was having 215 cfm of air flow and big intake poerts vereses the smaller ports. So it can be a delicate balancing act.
A non independent runner engine, like the 4-bbl six, runs pretty much like a
A 144-170 C1 to C5 head has 1.125" ports,
a 1978-1983 big log 200 or 250 has 1.65" average diameter.
1971-1975 2V is 1.65,
2005-2014 CI= 1.6" or so.
X flow Aussie was 1.575" for three years 76-79,
then way down to 1.3775" from 1979-1980,
then down even more to 1.33" from 1981 to 1992.
Ford Australia was prevented from ever doing anything 2V'ish again for 17 long years from 1975 to 1992. And then again for 11 years from 1992 to 2003 regarding turbos. They changed the cam actualtion in 1998 to an optional VCT system, and kept peak duration below 270 degrees.
The last OHV X-flow engine was worked on by SVOAustralia's Dick Johnson, and that engine could take a 280 degree cam in 250 X-flow with 1.73" rocker ratio and 480 thou loft and 215 50 thou duration...and give 196 hp SAE net at the flywheel doing it. Went up from 131 hp with just
a 280 cam,
500 cfm vac sec 2305 carb, and
a set of Perry headers and a little bit of port work.
Head Cfm was 145 at 450 thou lift in 1980 when released, then they went to a bigger valve head with extra mixture motion, but no extra cfm flow. With cam lift that was used, it went up to 165 cfm at 480 thou, and the head now had good mixture motion, but very, very small ports.
The best way I've explained it over the last almost 14 years on the forum is that engine size certainly changes the cam lope factor, and sensitivity to low stall converters. . Mike W 's head has the best mixture motion around, it puts plenty of spin on the mixture, and can cope better with low air speeds without the fuel droplets falling out of suspension. Its very much like the LS1 heads in the 1996 Chevy small block to date, some very special energy was spent of getting some movment into the mixture. So its B-I-G ports, which should hurt idle and when the engine comes "on" a bigger cam, isn't the issue it should be.
The square area in inches at the gasket face is actually pretty small compared to the 1969-1981 Aussie 245/265 Hemi engines and all years of 232/258/4 liter AMC Jeep L6 engines, so your all good for going up on "at lash" cam duration.