sp2p intake for 440 motor home

anyone used one? is fuel mileage improved?

Hi mGo ....is this a 413 or 440 ? What rear end gearing are you going to use ?

If you want an engine to breath through a straw, give it a try.

OP, your better off with a factory stock intake than that dud the Eddy only made for a very short time, it didn't work well on any motor I've heard of, let alone on a BB Mopar

Have either of you guys ever actually used one ?

A buddy ran one on his 440 in a 30 foot Wini. It was just a bit smaller than the Iron 4bbl but way lighter. (Whats a few pounds in a 30 foot Wini???) I think it has about the same port size as a B-400 2 Bbl. It should be a spreadbore mount.

His gave him about 3 more inches of vaccume across the whole RPM range. It did run flat at about 5200 RPM but the bottom end torque was better.

Now from under the bumper run 2 or 3 each 4 inch dryer vent pipes up to the engine. Put two in the air cleaners snorkel and the third to blow cooler air on your Thermoquad. Cooler air in those smaller ports should work.

Picture on FBBO:
https://www.forbbodiesonly.com/moparforum/threads/edelbrock-s-p-2-p-440-intake.139948/

never ran one in a big block, but i gave one for a small block to my one buddy for a 318 in a 72 duster. that thing runs real good with a 2.94 gear, 500 elelbrock carb, and a stock converter, but does run out of steam around 5200 rpm.
he never runs it hard anyway, so who cares ? it works for him.

I did one in a 318 application too. It was a win in every way.

Add me to the list of people who ran one of those on a 318. 69 motor with a comp 252 cam, 625 AFB, in a 79 short bed 2wd truck with manual steering and brakes, 833 OD and 3.55 gears in an 8-3/4 from a 60s truck
I couldn't believe how well that thing ran. The way I used that truck at the time I should have had a 1 ton. Towing, hauling with the back bumper about dragging at times, but when empty I drove it like I stole it, in those days. Great mileage when empty or nearly so, plenty of power for what I was doing. Idk how much of how it ran had to do with the intake but I'd try another. As far as the running out of steam at 5200 revs, I can honestly say that I don't think that I ever tried to get much of anything that I have ever owned much over 4000 revs.
So if that was the only limitation, it wouldn't bother me at all.

Back when I had carbureted vehicles I would put a vacuum gauge on to my vehicles quite often, looking for that last little bit that I could get out of them, and it did seem like I had more vacuum on the gauge from that engine than any of the other 318s that I had around then, which were quite a few.

Of course the engine made more vacuum. The engine was trying to suck air through a more restrictive intake.
The same idea is in play with a 950 Holley on a 318 versus a 2 barrel. Less restriction means less vacuum.

My one SP2P experience......

396 BBC in a 68 Camaro........ it was horrible.

I’ve never experienced anything quite like it.

I tried multiple carbs on it, and they all had the same trait.....or rather, the trait was consistent with a few different carbs.
First off...... the motor was absolutely “done” at 4500.

If you were cruising along pretty good at say 3500-4000..... and then stepped on it, the farther you pushed the pedal down the weaker it felt.
It didn’t feel strong at any point when driving the car.
It’s not like it started out great then nosed over...... it was just weak everywhere.

We pulled it out and dynoed it........283hp.

For a low end grunt 440, I’d use the std Performer.
I had one on a re-ringed 440 in my car for a few years...... that thing had fantastic bottom end snap.

Let’s hear some MPG numbers in everyone’s experience? ....

On a 440 powered motor home, class A,B or C?
Probably near 8.5 MPH with Grandma driving, 5.5 with me driving it

No YOU .., 5.5 SPP ... smilies per post !

And I hear Tom is going to start charging you 1$ per smilie over that limit !

And ur a more self-professed seasoned citizen than Granny is ... 5.5 MPH driving a motor home!

In the mid 80's I put one on a 305 Chevy half ton pickup, with a 400 Holley. It made the 305 more of a dog than it already was. I lost 4 mpg over the factory 2bbl. I yanked it and put the stock intake and carb back on. I can't imagine why anyone would want to use it on a 440. As stated, the factory intake or Eddy Perfomer makes better sense.

Yo eL ..... BLAME IT on that pig fat Berri crab !

But seriously... your experience does not match OTHER PEOPLES hands on experience that actually have used that piece for an extended period of time

CLEARLY.... it is not a horse power piece ... but as far as low rpm GRUNT and MPG ... it works.

But as I asked mGo... what’s his gearing ... that’s a big factor

On a BB Mopar the manifold swap is as easy as it gets...... so if the OP tries the SP2P and doesn’t like it...... it’s an easy swap to something else.

I would have to imagine that a pushing a MH along is similar to light towing.
In other words, you’re rarely cruising along at low rpm and very light throttle settings.

The motor is “working” 90% of the time.
Especially if you’re towing with the MH.

I can see where if one were to be able to run a motor in that low rpm/low throttle situation the SP2P might be able to be optimized to see a slight gain in mileage........ but if the motor will be primary operated in a way where the throttle is fairly open, in mid-range rpm, and you’re trying to make some power for hauling........ it def wouldn’t at all be my choice.

I’m not telling the OP not to try it if he’s inclined to........ I’m just informing him to be prepared for the possibility he won’t like it.

THAT ALL DEPENDS... on the load you put on the motor ... speed and weight ..,,

If you drive the MH in a sane manner ... 60-65 mph ... you can get DECENT MPG.

my buddy's 318 gets around 20mpg if i remember correctly.
but as i said earlier, he and his wife, doesn't beat on the car like i would.
i got that intake way back in the 77-78 time period, and i was interested in the holley carb that was on it to re-sell.
i made out good back then, and he made out good when i gave it to him.
one of the reasons i "think" it works so well [for him], is the fact the runners are the 318 port size, which keeps the port velocity up, and the mix doesn't crash into the port openings on the head like so many other intakes with the 340/360 port openings do.
just my guess.
your mileage will vary.

U remember .. you thimk ... you gUeSs ? .. whatever happened to the guy who CRS ?

him's still HeRe.
got gOoD days and bAd days..............

I hope the OP tries it and reports back

A little off topic but related. I've wondered how fuel injection would work on one of these older motor homes. I know where a pretty good looking Travco is.

I don't think it would be a worthwhile gain. EFI is great for cold-starts, warm-ups, short trips and town driving. In a motorhome where you fire it up and drive for hours fully up to temperature, well this is the type of driving a carb is at it's best. Sure EFI would be better, but I don't think better enough to justify the expense.

THINK the Plastic Fantastic ! ... with a 02 read out gauge and a simple water injection system you can tweak it to pretty good MPG !

When I bought my AMC Javelin, it had an SP2P and an Edelbrock 600 on top of the 360. The car ran a best of 15.1 to 14.9 in the quarter at Spokane Raceway. I later switched to a Performer and a Holley 600 (and ok, swapped to 3.15 gears from the 2.87) and picked up almost a full second in the quarter plus gained the ability to bark second gear. I used to have a timeslip in my wallet for my best run of 14.2 @ 99 mph, but it faded away.

(Yes, I realize that's slow. But the car was just my basic daily driver street car.)

SP2P's work better on 318's, Ford 302's, and Chevy 305/307's. Big cubic-inch engines are strangled by them. I'm not kidding! The ports are literally the diameter of a dime! When I swapped from SP2P to Performer, I was shocked at how tiny the ports were on the SP2P.

Yeah, you could plug them with a marble.

The intake ports that are up against the cylinder head ?

I’ve seen A LOT of diff models of the SP2P intakes ... and that’s not my observation at all.

RamMan ... I’m surprised the SP2P did as well as it did ! It is in no way a HIGH PERFORMANCE intake manifold.

What it’s for is low rpm GRUNT throttle response and better MPG..... and the carb should be tweaked over stick

I’ve even SEEN people making flaming mistakes with the SP2P .... like blocking the heat crossover!

On the 440 Sp2P we sat it down next to a 1968 383 2bb Iron boat anchor. the ports were about the same on both the carb and head ends. So yes a Marble may block it but its a big marble.

Understanding on a 440 a 383 2bbl port is NOT a race port but its not that bad if you KNOW you will not be drag racing your 32 foot long Winnabago. Will it pull past 4500 RPM, YES but it will be lazy.

The head side of a 383 2 bbl intake port is the same as a SP2P 440 ?

I haven’t seen that type boat anchor in a loooong time but I sure don’t remember that

that intake needs to be thrown as far from your motor as possible.

Well od ... TOSS IT right here .... these intakes worked GREAT on big boats like big Chrysler wagons and Imperials tooooo !

Doc, last time I seen that SP2P 440 was about 18 years ago. He had the Iron 440 4bbl next to the Iron 383 2bbl next to the SP2P 440. Yes it was smaller than the Iron 440 one.
I know it was bigger than the ports on my SP2P 318 that we had on a 1965 Dart GT 273 (with ported 66 273 heads).

Just because it had SP2P on it, not all of them had 260Ford-265Chevy-273Mopar size ports.... That would be stupid.

Guess the OP just needs to put a Tunnel ram with two Domanators on his Motorhome.

Sorry to post and run had some stuff come up. Anyways, 32ft Travco, 32" tall tire, 4.56 gear, 518 trans, 440 with KB184 pistons, 452 heads set up properly for .040 quench, cast iron manifolds, and a thermoquad for starters.

RPM calculator in overdrive shows 60mph at 2000 rpm, 70 at 2300. With 400 plus ft lbs of torque from 2000 to 4000 I don't know why I would ever spin it higher than 4k.

Idea behind the intake is if it will increase fuel mileage from 7.5 to 8mpg that equates to about a 6.6% savings in gas. Hoping I can do even better than .5 mile per gallon improvement with the step pistons and quench.

I have considered a holley sniper only because it would adjust for altitude while traveling out west.

And,..... Whats your 60 foot time?

Someone said, way up in the posts, to try it and see. Whats it take to swap a manifold on the 440? Drain the coolent, undo the bolts pull the iron anchor off and with some new chinawall seals and a squirt of RTV and 'Bob's your uncle'.

I think the Thermoquad will bolt on to the SP2P. And if it restricts air flow, the Thremoquad will still only flow what the engine can pull.

No need to drain the coolant for an intake swap on a 440.

Wow mGo ! ... is this combo all done ? ... or jsta planned ?

Your 8 mpg goal ? ... you should be able to get that with a pig fat Berri crab !!

What will your driving habits be ? Keeping up with traffic or a easy cruise in the far right lane with the cruise control clicked at 60 or so mph ?

Just planning stages now. Starting to gather parts hence the question about the intake. I have the 440, 518, and adapter already and will start building them shortly.My wife has a couple years left before she retires and we start traveling. I will be pulling a double decker trailer with my challenger and a small boat on it so 65mph probably as fast as I would care to drive in the wide open spaces.

UNLESS you know what cyl wall thickness in that 440 ... I would consider going with a 413 WITH those goofy heads. BUT with a ton more compression.

You plan on running premium fuel ?

I am hoping to get by without premium. Probably will run 89 octane. Compression ration should be between 8.5 and 9 to 1 with 90 CC heads. Plan to use an MSD adjustable timing control so I can pull some out if needed. Really want to do a 440 so I can use the step piston design. Want to try to get some decent fuel mileage if at all possible. If there were more piston choices for the 413 it would be a no brainer.

So if you had piston options YOU WOULD consider or go with a 413 motor and those industrial heads ?

I have one on my 440 right now, and I'm not very impressed. Like everyone has said the runners are tiny! It is probably done by 5000 RPM. Fuel injected 1968 Charger, 1976 or 78? truck/smog 440, A-833 and a Dana 60 with 3.54 gears. Averaged 11 or more MPG last year, would improve to 14 or so on the highway. I could get better mileage, if not consistently, out of another 440 with the Street Dominator. I would think my application would be good for this manifold but that's not how it's working out. Any 440, even a low compression one with a broomstick for a cam would demand and benefit from more air than this manifold can provide. I can only imagine better sorted out 440 in a motorhome would be strangled by the SP2P440. It might work okay on a 413 but not a 440. I mean a factory 4 barrel intake blows this thing out of the water torque wise.

I would use almost anything else, if this 440 makes it back onto the road, I'm definitely putting a Performer RPM on it

Absolutely. It is the best motor Chrysler built for an RV or truck application.. Sodium exh valves are a big plus. I don't know much about the head chambers or what it would take to get any type of quench though.

Well metLOAD .... before you trash that intake drop it into the mail TO ME.

Yes the ports are TINY.... specifically cast that way by Eddy !

DONE at 5000 rpm ? I’m surprised it ran up that high !

You need to explain your combo better

Just a quick question at this point .... how much investigation have you done on the 413 ... past the knowledge of the lack of piston choices ? Do you have access to a 413 core motor ?

I've used and built 5 or 6 of the 413 industrial and or marine blocks for race cars and street cars I use only the blocks, crankshafts and some of the fasteners depending on which heads I'm going to use
The last one is going into my 1963 Plymouth Fury with a Mopar brand 4.100 stroke crankshaft in it, 7.100 long BB Chevy type Molnard brand rods. I had either Autotec or Diamond make the pistons for it for pump gas using 440 source 80.0 CC heads.
I had the 413 crankshaft offset ground to BB Chevy rod journal size and increase the stroke to 3.91 and used that crank in a later model (1976 casting) 440 block for another pump gas motor with 440 Source heads

good points seaBee ... so what have you done with all those heads and exh mans?

Back in the 70's, two 413 heads, two exhaust iron logs and the iron intake went to make 1 new Toyota. No one wanted them.

.....add that massive water pump housing AND the pump itself and yurr probably right !

Buttt ..... log manifolds ? .... these are actually an impressive set of exh mans ! The only issue they have that I'm aware of is ... IF the exhaust system is not properly hung off the manifolds - they can break when heated red and sometimes WHITE HOT.

No particular knowledge or expertise claimed Doc. I have read they make more torque down low than even a 440 and know the 413 industrial/motorhome versions were built to last. But I am all ears and willing to listen and learn.

Do you have access to a good core motor ?

440s yes, no 413 though. But I see the motor home engines for sale locally on craigslist all the time.

Mopar has made two different version of their truck and motor home motors on the 318, 360, 361 C.I. HD B motors, 413 and 440. they can come in the regular ratings and the -3 extra heavy duty rated motors, the 440-3 blocks and heads have extra cooling holes in them for the exhaust valves, the regular 440 standard rated home motors don't
All the Mopar H.D. dash 3 motors last a lot longer under heavy use

Real quick —

Do you want TWO of them ... for FREE ? I have NINE of these up in northern Michigan and if you would pick up four of these and hold two for me in Atlanta... it’s a deal.

As I said before ... seaBee had some good suggestions.

I did some figuring some years back and DID FIND my first piston option and that was a set of std bore 426 max wedge 11 to ones

SHOULD be pretty close to perfect with those industrial heads at almost ZERO DECK ....and fantastic quench BECAUSE it’s a closed chamber head .....

BUTTT that closed chamber is something like 110 cc !

That is a very generous offer sir. How far north in MI are we talking? How soon do they need to be moved? I might be going back to visit family this summer in the Detroit area but no specific plans yet.

49633 ... near traverse city.

I have AT LEAST until October 5 ... it would be a pleasure to give these to someone who would actually DO something on the upgrade of this motor

You living in FL now Doc? What part?

I’m in Bradenton FULL TIME now. I sold that property in October...,

I still WANT to do some tweaking on the 413 but I don’t think I can do ANYTHING LIKE THAT in the shop I have now ..., probably going to build one out in the rural area.

Do you know the valve sizes in the heads ? lol

And I’d NEVER CONSIDER changing them !

I don't know about the valve size. How far down in the hole are the pistons? Any idea what compression height is? Wonder if a hemi length rod would bring the piston up high enough, or a 3.90 offset grind crank? Maybe with a 383 piston? Just thinking out loud and spitballing.

Valve sizes ... you better be sitting down ... 1.88 1.50 ......

BUTTT excellent for the application

THOSE are the only specs that I KNOW .... I did measure the deck height of the piston ... the width and depth of the dish in the piston etc. I did write them down but I don’t have them in hand.

Yes there’s the hemi rod option ... and the 4.15 crank with the 383 forged flat tops but I don’t have the spec sheet.

BTW ... I still have a 220 Travco UP THERE !

With valves that small I can't imaging any concern of the sp2p intake being a bottleneck and causing any issues.

I had a deal worked out on a 320 Travco but it fell through. Really would love to find a big one as I plan to cross the country and live in it for months on end while doing so. I like the idea of starting out with a fiberglass body so I don't run into the typical water damage older rvs have.

Do you have any idea what rods are in the 413? What size rod bolts? I like the idea of a 1/2 rod bolt in a hemi rod, but I tend to want to overbuild stuff so I only have to do it once. I still love turning wrenches building engines on a stand, but the climbing in, out, under, and around to remove an engine or trans isn't easy on my old body anymore.

The 361 and 413 industrial motors had the standard B/RB 3/8 rod bolts and nuts.
The OEM street hemi rods have 7/16 bolts and nuts, some of the race only hemi rods Mopar use to sell had 1/2 inch bolts but I wouldn't consider them in any low RPM pulling motor for truck or motor home use
Why add useless weight like that to the rotating assembly with those really heavy pistons

So the 320 Travco deal is totally dead ? There are lots of 270s out there but personally I’m not a fan of the sloped back - it KILLS inside living space.

The heads ? ... then consider the valve stem size on the exhaust valve - huge.

I sat down and did a whole lot of figuring and wrote it all down ... but that paperwork seems to be misplaced. I had also considered going the simple CUSTOM flat top piston route with a stock RB rod with a way higher CD.

IIRC - the cost was not that bad because it would be a very simple design

Well seaBee ... ... the weight is not that huge PLUS the fact that you’ll be cutting some of the weight off the piston

Those HEAVY pistons ? The huge dished stockers in the motor ? those are nothing but door stops or paper weights in the end

That particular travco deal is dead, but there will be another. Really just looking for mostly the shell anyways as I will go through the whole thing. Have thought about buying a later model totaled RV at the salvage auction to get the systems and interior to retrofit if I can get one on the cheap. My craziest thought is a travco with a slide out.

I am sure the valve stems are bigger in part to transfer heat out of the valve into the head. More surface area means greater heat transfer. Probably have a nice fat valve face to seat contact area as well like the marine engines.

Do the exhaust valve seats have hardened inserts? Does it have exhaust rotators on the springs?

Doing some math I think you are on to something that the 11 to 1 piston would work well, but I can't find an info on the dome size other than it is .063 in height. Anyone know what CC's that dome is?

Compression height to flat part of 11 to 1 being 2.111 makes it .029 out of the hole if the block were to spec. The run of the mill mopars I have built are always tall. Is the 413-3 closer to spec or similar to the others? In reality probably close to 0 deck or slightly above. Close enough to manage quench with head gasket thickness. Thinking I would like to get to 9 to 1 compression. With the quench set right it should run on pump gas without problems. Could always fill up with high test if needed when going through the mountains.

A concern I have is those sodium valves. Read where some old Ford engines that use them had problems with them breaking if the motor had sat for a while before use. Is that a common problem with all sodium valves, or just poor blue oval engineering?

Thanks for the input Cab. I guess if ma mopar designed the -3 engines with 3/8 rod bolts they must have known what they were doing.

Real quick .. gotta get busy ....

I’m sure that the dome is bigger than 063. I do have a set - I’ll locate them and double check them.

Never heard an issue with valves breaking ... and yes they have replaceable valve seats on the exhaust side.

Not a huge travco but its a 26-30 foot 1968 Chinook Fiberglass on a Dully chassis and a Poly Teen on Market Place. $900

https://www.facebook.com/marketplace/item/616067065634090/?ref=feed_rhc

huh I thought the Poly was history by 68....

I do not own or know the owner of the RV above

I thought they still made the Industrial Poly 318 past 1967 in Canada only. I do not know where a 1968 Chinook chassis RV was made. Could have been they had ten 58-67 chassis on stock and its the date of the body manufacture in 1968.

Oh my goodness ... that Chinook ... with a poly 318 ? ..., talk about UNDER POWERED !

They also have the small 5/8 spark plugs cause there is cooling passages around the plugs to keep them cooler,ran one of these engines in my Jensen Interceptor they where notorious for running hot.

Nothing a a stroker kit wouldn't fix.

Any of you guys happen to have a scrap 413 or 426 max wedge 11 to 1 piston kicking around? Doesn't need to be useable I just want to take some measurements.

The more I run numbers the more expensive the 413 proposition becomes. I already have a 440 with 6pack pistons. If I get them to zero deck the compression comes out to about 8,75 to 1 with the 413 head chamber. Is this doable, or are there different coolant passages in the block?

What’s the deck height on that 6 bbl short block ? ... I think ZERO DECK is a blueprint spec not a production line number

If your going to put this motor in a class A motorhome make sure the pistons tops are really thick for the extra heat in the combustion chambers that the motor will make pulling the heavy motor home

It has been decked already before I got it. Bought a bunch of stuff from a guy that was moving to California a while back. If it is not exactly zero deck it is very close.

Thanks Cab. Any advice on piston choice is appreciated. The pistons mentioned are TRW #2355 .030 forged pistons. As heavy as they are I would think they should work but have not measured the thickness of the top. I also have on the shelf a set of KB 237 flat tops that are .040 over with very similar compression height.. I know the KB's could run a tighter clearance but don't know if they would stand up-especially with the top ring so high. The TRW's are old and would swell and require a lot of clearance.

What rings would you chose for this application?


Aren't there some 440 industrial motors that have the same type water pump and heads? Are the heads the same configuration as the 413-3 with a closed chamber and sodium valves?

I'm sure your six pack pistons have the standard 5/15,5/16, 3/16 ring pack piston grooves, make sure though , and then order a set of rings for a motor home motor in the proper bore size if your piston top are thick enough to use in that motor for your deal
The TRW should have the needed piston to cylinder wall clearances built into them, you might want to add another .0010 to be safe though
Take one of those pistons and measure it where you should on the skirts at room temps and then stick it in a preheated oven a little over 250F and remeasure it to see how much it grows at those temps. , be careful so you don't burn your fingers also
On the 440-3 motors they are no where near like the 361 and 413 industrial motors so don't count on finding any 440 or 440-3 motor with those early heads and water pump timing cover like those on the early, pre 1973 H.D. 361/413 motors.
As far as the 440-3 valves I'm not sure about them or how they where made

Doc or Cab, you guys wouldn't happen to have a 413-3 piston laying around somewhere would you? I'd like to get my hands on one and do some measuring. Thinking about a hemi rod option. Or maybe someone has info what the pin height on these pistons is?

You looking for the 413 industrial piston compression distance ? .... CD ??

I don’t have any of those motors here OR the specs but I’d bet my life you’d be totally safe with that rod using any type of 383 or 413 piston. But I’m also sure that you will need to do some major shaving the piston tops to get a good quench.

And you would HAVE TO adjust any of that based on the deck height of the block you wind up using.

And NO WAY would I use that industrial piston in this project. The dish in that piston is huge

Thanks Doc. I got these specs from a guy on ebay regarding the 413 motorhome cam. He has some NOS ones listed. Really surprised how little lift it has. Smaller that a 318 in that regard.

cam lift int .240" exh .240"

valve lift int .360" exh .360"

adv. dur. int 260 exh 260

effective timing event @.050" cam lift

dur. int 193 exh 194

opens int 10 ATC exh 27 BBC

closes int 23 ABC exh 13 BTC

overlap 44

lobe line int 106 exh 110

mG .., that cam I would trash too .... never really made any decision on a cam choice but the cam tech THESE DAYS has to be way waaaaay bester than late 60s !

Yes sir I totally agree.

Was looking at this baby Lunati but I am no cam expert.

https://www.lunatipower.com/voodoo-hydraulic-flat-tappet-chrysler-361-440-253-258.html

Hydraulic Flat Tappet. Very strong torque and increased HP for 383-440 cubic inch motors. Compatible with stock type fuel injection. Works great for pleasure/ski boats, and mild towing applications.; Advertised Duration (Int/Exh): 253/258; Duration @ .050 (Int/Exh): 208/213; Gross Valve Lift (Int/Exh): .454/.454; LSA/ICL: 112/108; Valve Lash (Int/Exh): Hyd/Hyd; RPM Range: idle-5000; Includes: Cam Only


I know what works in a street build but I admit to being out of my depth with the motorhome stuff.

But, I am learning thanks to you guys.

Me thimks you should look at a HEAVY TOWING APPLICATION.

I was going to suggest calling General Kinetics... but they were bought up by Lunati I believe. Maybe even try Racer Brown.

Used to have some dealings with GK many moons ago ... and they would grind up a special cam for a couple of $$ more