New to group 250 owner need some advise

[Econoline]

Hi everyone, been lurking this forum for a bit. It's been very helpful to me.

So, I've recently acquired a 1970 250 out of a Mustang which I plan to install into my 64 Econoline with an AOD behind it.

I've measured the current deck height @ .103" and the head chambers @ 65cc(only measured #1 so far)
I've now got it all torn down and ready to send to the machinist and have the block cleaned, bored, honed, decked and new cam bearings installed.

My plan is as follows

Bore cylinders .030"
Deck the block .020"
Have crank cleaned and polished and rotating assembly balanced.
Install Sealed Power P47830 pistons (1.582" compression distance) milled with mirrored chamber shaped dishes @ 8-9 cc's(found a cnc piston guy that will do it)
Moly Rings
Install Clay Smith cam and lifters
New timing set
Have larger valves installed - 1.75/1.46
New springs 289 or 302?
Install the adjustable rocker assy from my 144 and new cupped end pushrods
Carb adapter to Weber 32/36 DGV

My questions are these,

Which cam to use? Was planning on 264/264/112. Plan on using as daily driver around town, some highway usage, hence the AOD. Want it to idle smooth and will have auto and going to install power brakes.
Similarly how much to degree the cam, what is the practical difference from 0 to 2 to 4 degrees advance? What are the disadvantages if any or any of the configs?

Should I go with 289 springs or 302 exhaust springs with a 264/264/112 clay smith cam? I've read some contradictory info regarding this. This will be a daily driver for the most part and I don't want to needlessly wear anything by having too much spring load. Also, will either of these springs require modification to the spring seat or head?

Will standard length pushrods be OK with decking .020" and using the the adjustable rockers?

On the Weber, if I use the 1v to 2v adapter, will I need a spacer? If so what is minimum spacer thickness required to clear the valve cover? I have some height clearance concerns as it is going to the 250 in my doghouse.

With the above configuration what C/R should I shoot for to stay on low or mid grade fuel @ sea level? Right now I'm looking @ 9.2-9.3:1 depending on how much I deck the block and how much I dish the pistons. I may deck less if need be to bring it down without milling too mush out of the cast pistons. I can't use the tables at Classic Inlines for Dynamic C/R b/c my configuration is different.

Here's a possible scenerio,


Input Values:
Number Of Cylinders - 6
Bore Diameter [inches] - 3.71
Stroke Length [inches] - 3.91
Combustion Chamber Volume [cubic centimeters] - 65
Head Gasket Compressed Thickness [inches] - .050
Head Gasket Bore Diameter [inches] - 3.81
Piston To Deck Clearance [inches] - .001
Select Piston Type
Dish/Valve Relief/Dome Volume [positive cubic centimeters] - 9
Volumetric Efficiency: 85%
RPM: 4500


Results:
Displacement, [cubic inches] 254
Displacement, [liters] 4.2
Static compression ratio 9.3:1
Cubic Feet per Minute required @ 4500 rpm, [cfm] 281
Estimated Horsepower @ 4500 rpm - 167

Any advice or comments is greatly appreciated

 

[rbohm]

Hi everyone, been lurking this forum for a bit. It's been very helpful to me.

So, I've recently acquired a 1970 250 out of a Mustang which I plan to install into my 64 Econoline with an AOD behind it.

I've measured the current deck height @ .103" and the head chambers @ 65cc(only measured #1 so far)
I've now got it all torn down and ready to send to the machinist and have the block cleaned, bored, honed, decked and new cam bearings installed.

My plan is as follows

Bore cylinders .030"
Deck the block .020"
Have crank cleaned and polished and rotating assembly balanced.
Install Sealed Power P47830 pistons (1.582" compression distance) milled with mirrored chamber shaped dishes @ 8-9 cc's(found a cnc piston guy that will do it)
Moly Rings
Install Clay Smith cam and lifters
New timing set
Have larger valves installed - 1.75/1.46
New springs 289 or 302?
Install the adjustable rocker assy from my 144 and new cupped end pushrods
Carb adapter to Weber 32/36 DGV

good combination.

My questions are these,

Which cam to use? Was planning on 264/264/112. Plan on using as daily driver around town, some highway usage, hence the AOD. Want it to idle smooth and will have auto and going to install power brakes.
Similarly how much to degree the cam, what is the practical difference from 0 to 2 to 4 degrees advance? What are the disadvantages if any or any of the configs?

with the 250 i would go with the 264/274/110. i think it is a better all around cam for the 250 in your application. advancing the cam adds low end torque which is what you want in your application, and four degrees advance is plenty. make sure that you do two things;

1: make sure you get the early timing chain set from the 69 or 70 250, as later sets, after 72, had a built in retard for emissions.

2: chances are that you will end up getting the later set as most places are only making those these days, so degree your cam carefully to see if it matches the cam card numbers.

Should I go with 289 springs or 302 exhaust springs with a 264/264/112 clay smith cam? I've read some contradictory info regarding this. This will be a daily driver for the most part and I don't want to needlessly wear anything by having too much spring load. Also, will either of these springs require modification to the spring seat or head?

i would go with the springs recommended by clay smith, in so far as spring pressures, both on the seat and open pressures, and keep in mind that the springs need to be able to handle the valve lift without coil bind.

Will standard length pushrods be OK with decking .020" and using the the adjustable rockers?

yes they should be. double check your rocker arm geometry to be sure though. the rocker arm pattern should be as close to the center of the stem as possible when you run through a complete round of valve events.

On the Weber, if I use the 1v to 2v adapter, will I need a spacer? If so what is minimum spacer thickness required to clear the valve cover? I have some height clearance concerns as it is going to the 250 in my doghouse.

you should have a fair amount of clearance under the doghouse. personally i would do a direct mount conversion over using an adapter, the adapter tends to limit airflow somewhat. but you dont need a spacer.

With the above configuration what C/R should I shoot for to stay on low or mid grade fuel @ sea level? Right now I'm looking @ 9.2-9.3:1 depending on how much I deck the block and how much I dish the pistons. I may deck less if need be to bring it down without milling too mush out of the cast pistons. I can't use the tables at Classic Inlines for Dynamic C/R b/c my configuration is different.

you should be good to go on 87 octane running as high as 9.5:1 compression, along with 14 degrees initial ignition lead.

Here's a possible scenerio,


Input Values:
Number Of Cylinders - 6
Bore Diameter [inches] - 3.71
Stroke Length [inches] - 3.91
Combustion Chamber Volume [cubic centimeters] - 65
Head Gasket Compressed Thickness [inches] - .050
Head Gasket Bore Diameter [inches] - 3.81
Piston To Deck Clearance [inches] - .001
Select Piston Type
Dish/Valve Relief/Dome Volume [positive cubic centimeters] - 9
Volumetric Efficiency: 85%
RPM: 4500


Results:
Displacement, [cubic inches] 254
Displacement, [liters] 4.2
Static compression ratio 9.3:1
Cubic Feet per Minute required @ 4500 rpm, [cfm] 281
Estimated Horsepower @ 4500 rpm - 167

Any advice or comments is greatly appreciated

that sounds about right.

 

[FalconSedanDelivery]

Sorry ,Not the Cam I would recommend with an Automatic , and the Ignition needs more than a recommended initial timing setting , a proper recurved Dist will be what you need , try running 9.5 ( a true 9.5 ) on 87 and you will kiss the engine goodbye in short order , although the cam mentioned would help with that unfortunately it will Kill low end ( what you want / need in a VAN !)

 

[Econoline]

yeah, I will definitely be upgrading the distributor.

FalconSedanDelivery, could you elaborate on you're cam recommendations? I have only a feeble grasp on cam issues. I'm concerned about vacuum needs for the tranny and brakes. It was my understanding that if I advance the 112 cam it would help lower the power curve. Also what C/R should I go with to be safe? The final static C/R will be accurately measured in so much as possible with actual final chamber volumes and deck height measurements. If I only deck the block .010" I should end up @ 9.1:1 with all other above specs being equal. Thanks for the help.

 

[Econoline]

rbohm, Thanks for the help, I initially overlooked your answers in the quote.

I was planning on getting the timing set from classic inlines, do you know if their set is the old one? Also, do you think there will be any problems using the 264/274 110 in stop and go driving around town with the AOD? And will it provide enough vacuum?

I'd like to do the direct mount with the carb but I'm a little concerned about money issues when I get to the head work. If it fit's into the budget when all the other work is done I may go for it.

 

[rbohm]

rbohm, Thanks for the help, I initially overlooked your answers in the quote.

I was planning on getting the timing set from classic inlines, do you know if their set is the old one? Also, do you think there will be any problems using the 264/274 110 in stop and go driving around town with the AOD? And will it provide enough vacuum?

I'd like to do the direct mount with the carb but I'm a little concerned about money issues when I get to the head work. If it fit's into the budget when all the other work is done I may go for it.

you can read a little about the cam i suggested here;

http://classicinlines.com/proddetail.as ... 264-HDP-10

it comes on at about 1900 rpm but has good mid range torque, and since you are going with the AOD, you can run a 3.55 to 3.73 rear gear, which you should be anyway with the heavier van. as for the direct mount carb setup, ask you machinist how much more it would cost you to have the log milled for the adapter, and bring the adapter with you so he knows how much needs to be milled' this is the adapter you want;

http://classicinlines.com/proddetail.as ... -200-2VC-W

you can have him do the initial machine work, and then you can finish it yourself as it is mostly opening up the log to fit the adapter, and then drilling and tapping the bolt holes that hold the adapter in place.

 

[Econoline]

I'm looking at Sealed Power VS-919 springs, is there any reason why these wont work?

Part Number VS-919 Specs:

Max Outside Diameter: 1.404
Wire Diameter: 0.192
Coils: 5.9
Closed Height: 1.6
Closed Press: 78.8
Open Height: 1.15
Open Press: 209
Type: S

Stock Springs:

Part Number VS-624 Specs:

Max Outside Diameter: 1.355
Wire Diameter: 0.177
Coils: 6
Closed Height: 1.585
Closed Press: 52
Open Height: 1.222
Open Press: 152
Type: S

 

[FalconSedanDelivery]

If your running an Automatic , and or Power Brakes , then I would NOT use a cam with less than 112 on the lobe separation , a cam starting to work at 1900 is still 1000 rpms above where you will be from at a stop light , if this was a Hi performance deal and you install a 2500-2800 rated stall converter fine, I have voiced my displeasure before with the so call guide , it is VERY easy to over cam a small motor. I am not a moderator , I have no ties to Mike , BUT I do want this site and MIKE to be successful , I have a fondness for these engines , I have built a few and they have PERFORMED , I have also been scorned , blocked on some of my opinions I am 54 Been doing this ( and DAMN Good at it for a long time ) My advise is free , and its your money , and time

 

[Econoline]

I appreciate your opinion, what cam would you suggest for my application?

 

[WerbyFord]

Econo,
I think FSD has some good advice, he has built a lot more Falcon 6 motors than me, my main focus is on the WerbyFord Gonkulator that compares to dyno data and predicts stuff.
I can comment though that, I've built lots of motors at 9.5cr. They ALL run fine on 87 octane regular.....when theyre NEW. But wait a couple years for carbon to get in there (happens to new cars too when Werby's Wife drives em too easy) and they knock like pigs. They are still fine on 91 octane but that is the backup plan.

So if you can aim for 9.3 max, maybe even 9.1, that is a better bet. I like keeping a zero deck, that actually raises octane tolerance.
I would cc your head now to see what you have. THen when you put in bigger valves, open it up a little and gain a couple cc's in the head.

As far as cam choice, here is what the Gonkulator thinks of your plan:
264-264 (214-214-112) cam at 4 advance
Torq 187 at 2000
Torq 225 at 3200
Powr 160 at 4500
HP* = 189 weighted average
Cam will be about as "rough" as a 429cj if youre old enough to remember those cars new.

Same cam at 0 advance
Torq 178 at 2000 -9
Torq 221 at 3300 -4
Powr 162 at 4700 +2
HP* = 187 loss of 2

For fun I ran an Erson rv10h 208-208-111 at 4 advance thru the Gonkulator
Torq 195 at 2000 +7
Torq 226 at 3100 +1
Powr 157 at 4300 -3
HP* = 189 weighted average, same.
This is the strongest cam below 3000 where you will use it most, and on the average should run about the same in 0-60mph or 1/8 mile if youre into that stuff. It will get the best MPG too.
Of course if you plan headers and a 4bbl later then I'd go bigger, but if this is the final build I'd go with something like this cam.
But its a pretty close call, the 214-214 cam will just be havin more Tude.

 

[rbohm]

If your running an Automatic , and or Power Brakes , then I would NOT use a cam with less than 112 on the lobe separation , a cam starting to work at 1900 is still 1000 rpms above where you will be from at a stop light , if this was a Hi performance deal and you install a 2500-2800 rated stall converter fine, I have voiced my displeasure before with the so call guide , it is VERY easy to over cam a small motor. I am not a moderator , I have no ties to Mike , BUT I do want this site and MIKE to be successful , I have a fondness for these engines , I have built a few and they have PERFORMED , I have also been scorned , blocked on some of my opinions I am 54 Been doing this ( and DAMN Good at it for a long time ) My advise is free , and its your money , and time

note that i also suggested that he run a deeper gear as well. but also note that the same same i recommended but with 108 LSA, start building power at 1400 rpm, where as at 112 LSA it starts building power at 2400 rpm.

 

[FalconSedanDelivery]

I know what the info on the cam says , I disagree and believe the wider lobe separation will start earlier, It may be the cam info got switched either way I stand by my recommendations

 

[rbohm]

I know what the info on the cam says , I disagree and believe the wider lobe separation will start earlier, It may be the cam info got switched either way I stand by my recommendations

i would agree with that except that competition cams says the same thing about their cams as well. i am rethinking my stance on cam design these days, and i have seen testing where the only changes was the LSA and sure enough the narrower LSAs made better low end power. and yes it is the exact opposite of what i learned 30 years ago.

 

[FalconSedanDelivery]

My experience is from the present ,the narrow lobe sep on a Log manifold will KILL manifold vacuum, a High Compression ratio would offset that , but we are talking 10.5+ , a log manifold , ( which acts like a single plane ) is NOT conducive to velocity WHEN you kill vacuum signal , Comp cams are based on SBC V-8 stuff unless its a custom grind , no where near what you want for a small cubic inch 6cyl , Crane grinds most of the 6 stuff on 112 ( the cam in my 250 was on 112) again I stand by my Experience , Not Theory

 

[Econoline]

I hear what you guys are saying and I tend to agree that any of the clay smith cams may be more cam than what I need. I don't plan on racing, I'm just looking for a fun ride to mostly tool around town and be a hell of alot better tan what the van has now. I like the idea of having some pep off the line. Better passing power on the freeway would be nice but not at the cost of the low end. I've now looked at all the otc cam grinds out there from isky, comp, clay, erson, and schneider. I think Werbyford's suggestion of the Erson 108/108/111 is a good one, good compromise between stock and performance. Drivability is important to me. My goal really is to optimize the motor and have a rock solid bottom end in the motor that I don't have to worry about, not go balls to the wall with it. And having that power where I will use it most, around town and getting up to highway speed, but still giving me a little extra on the top end makes a lot of sense.

 

[FalconSedanDelivery]

If you build the engine (the combo) for an 85% usage you will be happy , so many times Ive had customers want EVERYTHING , pull like a Diesel , Sound like a dragster , and SORRY cant be done , you either compromise ( and it usually runs as such ) or you build it right , or as I say it can be fast or half-assed , when it comes to small engines , and 250 is small , 200 even more so , And /but still I see cam recommendations ( even from some Manufactures! ) like its a 350 V-8 , it aint JACK !! build it accordingly , one more thing , think about a Solid lifter cam , with them you can get more , and still have lower end grunt ( think poor mans roller cam ) and NO they do NOT need constantly readjusted , metallurgy has come a long way since 1965 and a last thing , if you haven't purchased an upgraded ignition steer away from the DUI use a Duraspark , or a Pertronix converted 68 and up dist , better dists , less money , if you had a 1/4 drive ( early 144-200) then its a legit reason IMHO

 

[rbohm]

If you build the engine (the combo) for an 85% usage you will be happy , so many times Ive had customers want EVERYTHING , pull like a Diesel , Sound like a dragster , and SORRY cant be done

well said. even though i recommend certain cams for certain builds, i do suggest that you follow the rules for cam selection and ultimately make up your own mind. these rules that i go by are;

1: decide what you want from the engine, realistically. for instance do you want a daily driver, then figure an rpm range of 1000-4500. a toy would go about 1500 or so to about 5000 rpm. a street/strip engine you want something in the 2000 to 6500 rpm range.

2: determine what rpm range your engine will spend 80% of its time in

3: look at what the cam manufacturers in that rpm range

4: select the cams you like best from a variety of manufacturers

5: repeat 3 and 4 until you narrow the selection to one or two cams, then make a decision.

and any cam you select will be a compromise, so dont be afraid to perhaps fudge the rpm range slightly depending on what rear gear you intend to use. in your case a am that comes on at 1900 rpm is fine if you use a rear gear in the 3.55 to 3.89 range, and a slightly looser converter than stock, say one with a stall speed of 2000 rpm.

just remember that everything is a combination, and you want to select the best combination for your application.

 

[jahearne]

I'm running a 274/274 112* cam with AOD and built DSII distributor from ClassicInlines and it runs great with 3.50 gears out back. You can't degree the 250 because we don't have an over the shelf degreable (is that a word?) timing chain set yet. I'm running it straight up with 12 degrees advance at the distributor. Runs great on Premium fuel and 9.3 to 1 static compression. I think you'll be very happy with 264/264 112* and AOD.

 

[Gene Fiore]

You can't degree the 250 because we don't have an over the shelf degreable (is that a word?) timing chain set yet.

Actually you can degree a 250 by using an offset crank key. And if you are concerned about this throwing the balancer off you can do what my machinest did. He cut down on the length of the offset keyway to be the same width as the timing chain gear and installed this short keyway first and then cut the stock keyway to the proper length and installed that. This way the balancer is still in the proper position relative to the crank.

 

[jahearne]

You can't degree the 250 because we don't have an over the shelf degreable (is that a word?) timing chain set yet.

Actually you can degree a 250 by using an offset crank key. And if you are concerned about this throwing the balancer off you can do what my machinest did. He cut down on the length of the offset keyway to be the same width as the timing chain gear and installed this short keyway first and then cut the stock keyway to the proper length and installed that. This way the balancer is still in the proper position relative to the crank.

That works! I may give that a try.