Engine and Transmission Tech

I posted this on the "other" MG forum and it's provoked some interesting comments. So, in the interest of being and equal opportunity trouble maker...

Now that my project is actually looking like I may finish this year and that it's too damn cold (0 degrees or below for the past few days) to work out in the garage, I've had time to catch up on some of the build logs, internet stuff, etc. The only thing worse than a car builder with time on his hands may be a reformed smoker.

Following is the chronicle of the motor build for my B. This is the 4th small block Ford I've built, each time I've tried new things and gotten a bit more adventurous, developed more horsepower and, while I'm not expert, I've had the good fortune to hang out and learn from some folks who are. This dry sump version, is as extreme as I've gone but I know folks who are making a reliable (the key word) 550 + horsepower out of an SBF. I don't have the money (or the courage) to go that far but thought that a few of you out there that are contemplating an SBF swap or who may have already done one, would find the write up of interest. I included the build sheet (a bit out of date here and there) to give a sense of cost, parts sources, and manufacturers.

Both the guy who did the block work for me and the two books I used to decide on specs, claim it will make 400+ HP. I'm skeptical, to say the least, but you be the judge. Here's the link tot he write-up and the build sheet:[tempusfugitgarage.com]

> Pistons - Speed Pro Forged hypereutetic

Pistons are either forged or hypereutectic but not both. Hypereutectic pistons are cast pistons
made of an aluminum alloy with a greater amount of silicon added. This lowers the thermal expansion
of the aluminum, allowing tighter piston clearances. The downside is the pistons are more brittle.
Some forged piston alloys also have substantial amounts of silicon, others do not. Speed Pro makes
SBF pistons in cast, hypereutectic cast and forged. It's important to know which you have so you
can use the correct piston-to-bore clearance and ring gaps. Keith Black has explicit instructions
on ring gaps for hypereutectic pistons, especially if nitrous is contemplated.

> Damper was a 50 ounce from early 302 that was quite a bit shorter than the stock damper.

Eary 302's (those prior to 1971) used a balance factor of 28.2 oz-in (notice the units, its a product
of weight and distance, not just the weight). 1971 and later were 50 oz-in. When you're balancing
the assembly and buying a new damper and flywheel, it's generally a good thing to use the earlier
28.2 oz-in balnce factor. It doesn't take much mallory metal and allows the cast crank to live a
longer life at higher RPM. With 50 oz-in, the couple across the #1 main is large; in SCCA A Sedan
racing, it was fairly common for 50 oz-in 5.0L cranks to fail at the cheek of the rod throw. That
said, it's not a big deal if you keep the RPM under 6000 (I have one 50 oz-in 5.0L with 225K miles).

> Ford E302 roller cam with a 107 degree lobe separation, opening at 224, closing at 284.

Do you mean Ford B303 cam. Ford has a series of SBF roller cams (B303, E303, F303, X303, Z303).
None of them have a 107 degree lobe separation angle (LSA) though some, like the B303, are meant
to be installed on a 107 degree intake centerline (ICL). LSA is the average of the intake and
exhaust centerlines and, in the case of the B303 is (107+117)/2 = 112 degrees. Also, the 224
and 284 numbers are not open/close events. They are the durations, measured at two different
lift points 0.050" tappet and SAE seat, sometimes called advertised. The specs for the B303 are:

224/224 degrees @ 0.050" lift (284/284 seat), 0.480" lift with 1.6:1 rocker ration, 112 LSA

However, on your build sheet, you list the cam as M-6250-E303. That's a different cam with specs
of:

220/220 degrees @ 0.050" lift (282/282 seat), 0.498" lift with 1.6:1 rocker ration, 110 LSA

BTW, Richard Holdener's 5.0L dyno test book has a dyno test of those cams.

> Distributor gear (bronze)

The B303 and E303 cams are hydraulic rollers and are designed for use with Ford's steel
distributor gears:

[www.fordracingparts.com]

Bronze gears are generally used on billet steel solid roller cams and are sacrifical (can wear
quickly).

> Trick Flow double roller chain and gears.

Trick Flow doesn't make their own timing chains and gears. They repackage them from other
sources. It's a good idea to check the names on the chain links and gears. If the chain
says Rolon and is black in color, it is very poor quality.

> Ford 351C short-nosed water pump (reverse rotation) and matching timing cover.

The 351C is a different engine family which I don't think is compatible. The short nose
reverse rotation SBF water pumps are usually from the 5.0L Ford Explorer and Nercury
Moutainer. I think the '94-'95 5.0L Mustangs had short nose water pumps too.

> Comp Cam 1:6 roller rockers

Your build sheet lists the rockers as Pro Comp? Be aware the Pro Comp parts that I've seen
(and in some cases dyno tested) have been of low quality. I would not trust Pro Comp roller
rockers.

> New Ford Z-heads, 2.02" intake valves, 1.60" exhaust valves, rocker studs and guide plates
> installed. These flow significantly better than the popular GT-40 heads.

Agreed. Note there are several versions of the Z304 head. The Z304d and Z304p requires rockers
with an 0.150" offset intake pushrod cup. Those are available from Ford under the part number
M-6564-F351 in a 1.65:1 ratio. I believe Ford dropped the original Z304 and Z304a versions
which did not list offset rockers as a a requirement.

Your picture gallery shows cast iron exhaust manifolds. Z304 heads have larger raised exhaust
ports. Did you port match the manifolds?

> A vintage Autolite 4100, vacuum choke (set it and forget it) worked over by Pony Carbs in Texas
> (sadly now defunct) to flow 560cfm

There have been various flow numbers listed for the Autolite 4100 carbs. One of the guys on
the FE forum had several of them flow bench tested. He found the smaller 1.08" primary venturi
flowed 441 CFM while the larger 1.12" primary venturi carbs flowed from 503 to 528 CFM, averaging
520 CFM. The venturi size is cast on the side of the carb. What does yours say?

> Weiand Stealth, dual plane

Do you have any pictures that show the intake more clearly? I've got a Stealth here and it
looks different than that on your engine but the intake is obscured. I wonder if they
revised the casting? Does yours say Stealth at the front? Weiand made several other dual
planes for the SBF (Weiand 2P-180 p/n 8003 and 8006, Weiand Stealth p/n 8020, Weiand Action
Plus 8011) but it doesn't look like those either. Weiand has a newer SBF intake, the 8124
Street Warrior. The picture on their website shows "Action Plus" cast in to that intake
but it is clearly not the old 8011 Action Plus.

> According to Jack Edgerton and both books, this particular combination of parts and pieces
> should make something in the 450 horsepower range. I’m skeptical but, if it even gets close,
> I’ll be beyond thrilled.

Ford sold several 5.0L crate engines with the Z304 heads. One was the M-6007-750E which had
9:1 compression and E303 cam. With dyno headers and an M-9424-E302 intake manifold (Ford p/n
Edelbrock Performer RPM) it made 360 HP @ 6000 RPM and 330 ft-lbs @ 4800 RPM. With 10:1
compression, Z303 cam and Weber independent runner induction, it made 390 HP @ 6200 RPM and
360 ft-lbs @ 5000 RPM. The Z303 cam specs out at:

228/228 degrees @ 0.050" lift (290/290 seat), 0.552" lift with 1.6:1 rocker ration, 112 LSA

The M-6007-C347 crate engine was rated at 450 HP but that was a 347 with Victor Jr single
plane intake and a much larger dual patterm cam (232/240 @ 0.050. 0.563"/0.584", LSA wasn't
given).

> My guess, given the carburetor and manifold changes is something more like 350-375 on pump gas.

Compared to the M-6007-750E, your compression ratio increase will add a some HP but that will
be more than offset by the reduced carb CFM and the the iron exhaust manifolds will really hurt
the power. I've dyno tested headers versus exhaust manifolds on a 400+ HP 351C and the manifolds
cost 36 HP and similar torque. Mufflers are important too. We've tested some mufflers that
were down 50 HP to the better ones like the Mangnaflows.

> That estimate flies in the face of everything that seems to be popularly held but the dyno
> doesn’t lie so we’ll see when I get a chance to strap it down and get some definitive evidence.

Let us know how the testing goes. Do you know what jets are in the carb? There are a few sources
for Autolite jets now (I used to rob them from 2 barrel Autolite carbs) and I recommend taking
several sets of jets (smaller and larger than what are in your carb now) to the dyno. Keep a
very close eye the air-fuel mixture and also monitor the vacuum level at WOT. That will tell you
if you are starving for carb flow.

> In the meantime, even if it only makes 300HP or so, the car will weigh less than 1900 pounds when
> complete and is still going to go like stink.

Oh yeah. That'll be sporty for sure.

Dan Jones

Pistons - Correct, my error, they are hypereutetic. Rings were gapped accordingly.
Damper - An early style "short" damper is available for various 302 conversions in both 28 and 50 ounce imbalance (Speedway Motors and others). My fly wheel is 50 oz. hence the balancer matches. The short balancer save me 1 5/8" of the front, necessary for the dry-sump drive mandrel to clear the cooling fan. Even so, there may be a 1/2" clearance at most. It's a tight fit that also required some ingenuity when it came to the pump pulley.
Timing chain - Aware of the packaging, was NOT the black chain
Water pump - These are listed from Ford Racing using the 351 part number but are packaged for 302 conversions including the timing cover for applications (like mine) where the front of the motor needs to be as short as possible.
Roller Rockers - As I noted in the original post, there's been a lot of distance between the original build sheet and what I ended up with. Rockers are Comp cams for the reasons you mentioned.
Exhaust manifolds - As it would be I DID port match the manifolds then found I would not be able to make them work with the motor set back. While the final form on the exhaust is a work in progress, I'm currently working with set of tri-y full length headers that seem promising (trying to NOT go through the fenderwells).
Autolite 4100 - I'll check on the casting number. The carb came from Pony Cards in Texas (now out of business) a well-respected builder of vintage carbs for the Mustang crowd. It came with it's own spec sheet citing the 560CFM flow number. I have no reason to doubt it. I also have a 600cfm and a 750cfm Edelbrock on hand if I find I need something more robust.
Stealth manifold - I look and see f there any identifying marks but this is another vintage part which, I grant you, looks little like the version being currently sold.
Cam - Definitely E-303. Original plan was for a B but that was before I decided I wanted to actually drive this on the street. I've used both before and the E is, in my opinion, the more civilized of the two while the B seems to feel happier with single plane set ups like the RPM Performer series.
Your horsepower guess - I'm with you on that one but both the guy who did the block and head work and the guy who wrote the book, say different. As mentioned above, the cast headers are gone so I'm working with 1 5/8" primaries now. It's better than the cast but I'll still give some HP back with the Tri-Y design although, I have to say, they do look very cool. That's got be worth a could of horsepower, don't you think?

Agreed on the "sporty" comment. Car has no interior, glass body work except the doors so I'm guessing a dry weight of about 1900 lbs (maybe a bit less as there's no door glass, no nothing that it doesn't need to go forward). Even with 350hp and a good flat torque curve it should scoot along just fine. This was more an exercise in seeing if George Reid's claim of making 450HP out of a mildly reworked 302 was actually possible.

Testing won't be until late spring or early summer after I get the car on the road but will absolutely post the results once I get it to the dyno. However it turns out, it's been a fun motor to build and I have a new respect for learning how to make power with something other than a credit card.



Edited 1 time(s). Last edit at 01/27/2013 07:23PM by DC Townsend.

> Water pump - These are listed from Ford Racing using the 351 part number but are packaged for 302
> conversions including the timing cover for applications (like mine) where the front of the motor
> needs to be as short as possible.

Likely a 351W based part, not 351C based.

> I'll still give some HP back with the Tri-Y design although, I have to say, they do look very cool.
> That's got be worth a could of horsepower, don't you think?

You may want to pick up a copy of the PipeMax software. It's pretty good at sizing tri-y headers
and gives you bad lengths to be avoided as well as good ones. I'm working on a set of tri-y
headers myself for a different application:



They are for a mid-engine application which usually uses very short primary headers. I think
I can snake two smaller diameter pipes where a single larger one won't fit. We recently did
some header testing on a 351C and the best short header wasn't too bad at the top end but
gave away a lot of mid and lower range power (compared to 4-into-1 long tube headers). I'm
hoping I can buy the low and mid-range back with the tri-y design.

> The carb came from Pony Carbs

They did there own version with a larger secondary but a smaller primary.

> Stealth manifold - I look and see f there any identifying marks but this is another vintage
> part which, I grant you, looks little like the version being currently sold.

I contacted a friend a mine about the Weiand Stealth. He supplied the intakes for the old
Super Ford SBF intake comparo way back when and still holds records with SBF drag cars.
He used to rank the Weiand Stealth near the bottom of the list when it came to SBF dual
plane intakes but he said that Weiand re-designed (widened and lengthened the runners) it
to be more like his favorite Ford C90X dual plane (the intake Ford developed for the Muscle
Parts program). He likes the new version and said Holley/Weiand have redesigned a lot of
their line to be more competitive.

> Cam - Definitely E-303. Original plan was for a B but that was before I decided I wanted to
> actually drive this on the street. I've used both before and the E is, in my opinion, the more
> civilized of the two while

Agreed. I prefer the E-303 as well, especially with 1.7:1 rocker arms and beehive springs.

> the B seems to feel happier with single plane set ups like the RPM Performer series.

The Performer RPM series are dual plane intakes. It's the Victor Jrs that are the single planes.

> This was more an exercise in seeing if George Reid's claim of making 450HP out of a mildly
> reworked 302 was actually possible.

I've got that book and wasn't too impressed, though I was more interested in the 351C and FE
big block sections.

Dan Jones

"I've got that book and wasn't too impressed"

Dan,

Would you care to elaborate a bit? Other than I thought the information was bit dated (many of the parts he cites are no longer available) I thought his basic approach was sound.

And correct again on the Victor Jr. Reminder to never answer e-mail when your tired and not completely involved.

This particular Stealth manifold looks to be about 10 years old, at least. Not exactly a true "vintage" part but I don't think (operable word) that it's the newer design either.

David

Clan, If your using "beehive" springs, make sure you check them for run-out,(leaned over to one side). Especially on the stronger springs, this will cause excessive valve stem/guide wear. Some of these are rated to 400 lb./in. Good Luck, Art.



Edited 1 time(s). Last edit at 01/29/2013 01:25PM by roverman.

> Would you care to elaborate a bit? Other than I thought the information was
> bit dated (many of the parts he cites are no longer available) I thought his
> basic approach was sound.

Many of the people who write these sorts of books are not engine builders nor
automotive engineers. Instead, they are journalist majors who have little
actual experience with high performance engine building. They tend to copy
from magazine articles (which may have gotten it wrong to begin with) or other
books or they source material from interviews with an engine builder. The
latter is fine, as long as they know enough to put what the builders say in
the proper context. Unfortunately, George gets several very basic concepts
wrong along with a number of details, as well as omitting many important known
weaknesses within a given engine family.

For instance, George states: "Smaller tubes increase back pressure which,
thanks to valve overlap, helps you get the most out of combustion." It is
a complete fallacy that back pressure aids performance. Ideally, you'd have
no back pressure. When a smaller diameter or longer length header primary
pipe or collector helps a particular engine it is due to the change in the
timing of the wave dynamics that occur within the exhaust gasses, not due to
an increase in back pressure.

In expressing his preference for cast cranks over steel forgings in performance
applications, he states: "What makes a cast crank more forgiving than a steel
crank is flexibility. A cast or nodular iron flexes in extreme conditions
where a steel crank will not. Steel cranks tend to snap under great stress."
He gets this completely backwards. It's cast iron that is more brittle than a
steel forging.

When attempting to explain camshafts, he states: "Typically, a dual pattern
camshaft will run shorter exhaust valve duration due to less time required
to scavenge the exhaust gasses at high RPM." Actually, most dual pattern
camshafts tend to have longer, not shorter, exhaust duration. He goes on to
say "Keeping the exhaust valve open longer is what helps a street engine" then
contradicts himself by stating "Running a dual pattern camshaft on the street
doesn't make much sense because we lose torque at low and mid range".

Increased exhaust duration is often employed on engines to hold power longer
past the HP peak. If the extra exhaust duration comes at the expense of
increasing total overlap, then low and mid-range power may suffer. For that
reason, many builders prefer single pattern cams for street engines that spend
most of their time below the HP peak RPM. However, many other factors enter
into the equation including the intake to exhaust flow ratio and valve
diameters so cam specs are oftened tailored to the specific cylinder head
flow characteristics. He also states: "Small blocks need more valve lift than
big blocks". Small blocks are often limited by valve size (which in turn is
limited by bore size). The ability to increase flow is directly proportional
to the valve diameter so a smaller valve size will flow limit at a lower lift
than a larger valve. For that reason, big blocks with larger valves can
benefit more from higher lift than small valve small blocks.

Concerning open versus closed chamber heads, he states: "Open chambers give us
improved performance with lower octane fuels." In reality, open combustion
chambers are more prone to detonation. He also states that "Closed-wedge
chambers like we see on the 351C-4V raise the compression to 11.0:1 with flat
top pistons" and implies this is not compatible with today's fuels. In reality,
the compression ratio is around 10.25:1 with flat top pistons, unless the block
has been decked, and runs just fine on premium pump gas. The quench effect of
the closed chamber 351C-4V heads tolerate about one point more compression on
the same octane fuel as the open chamber 351C-4V heads.

When discussing intake manifold types, he states: "Single plane manifolds make
poor street manifolds." This is a gross simplification and there are many
applications where a single plane intake manifold makes a very good street
manifolds. In dyno testing intake manifolds, I've found the variation within
a type of manifold (single or dual plane) can be very large. For instance,
I've seen a 50 HP difference between two dual planes on a 351C. I've also
seen an excellent dual plane get beaten across the entire rev range on one
engine combination by three different single plane intake manifolds and
the same dual plane intake manifold beat those same single plane intakes on
a different engine combination.

He refers to the simple carb sizing formula and states "351W and 351C need
500 to 600 CFM" and elsewhere he suggests you can increase that to 650 to 700
CFM if racing. A 500 CFM carb will begin limiting power of a 351 at around
250 HP. Even on the low compression 1972 to 1974 351C-4V engines, the stock
carb size was 715 CFM. Previously, I've derived the carb sizing formula here,
pointing out the flawed assumptions that lead to its mis-use.

Comparing the 351W and 351C, the author states: "The 351C sports a heavier
block". A 351W block is within a few pounds of a 351C block (around 170 lbs
on my bathroom scale). He also claims "It is not a lightweight casting either".
Both the 351W and 351C blocks are thin wall castings. He further adds "Ford
blocks such as the 351C, 351M, and 400M are notorius for cracking." In
reality, it is only a particular run of 351M/400 blocks cast at one of the
two casting centers (those cast before March 2nd 1977 at the Michigan Casting
Center as opposed to the Cleveland Foundry) that have the cracking problem due
to a problem with the coring tooling.

He also recommends using 351M/400 heads as an alternative to the less common
351C-2V heads. While the early 400 heads are okay, the later 351M/400 have
a casting bulge hanging in the exhaust port that can't be ground away as
there's a coolant passage in the way. No where does he discuss well known
problems with the OEM 351C valves. Furthermore, he states "351C-4V heads
don't offer sufficient low-end torque for street use because their ports are
too large." The small port 1969 351W-4V was rated at 290 HP and 385 ft-lbs of
torque. The 1970 351C-4V was rated at 300 HP and 380 ft-lbs of torque. Not
much of a difference in stock form. In an early attempt at controlling
emissions, Ford dropped the compression by 2 points and retarded the cam 4
degrees on the 351C which did hurt torque on later 351C-4V engines but torque
also suffered on early emissions eera 351W engines. While it's true that
351C-4V ports are overly large for many appications, they can make sufficient
torque for most street applications if you know how to properly build them.

I had more examples typed up but accidently hit the escape key and lost what
I'd typed.

Dan Jones

"I had more examples typed up but accidently hit the escape key and lost what
I'd typed. "

You know Dan, if you wrote a book on 302s, I'd buy it and read it in a heartbeat. Thanks for your willingness to share, what would appear to be, your considerable knowledge. I appreciate it.

David

I'd publish it. This is an extremely interesting and informative thread. Thank you for taking the time to compose detailed posts.

"I had more examples typed up but accidently hit the escape key and lost what
I'd typed. "

That irritates me more than just about anything. On some sites it seems like there's even some sort of voodoo going on that dumps your text just as you're getting ready to post. It's a hard thing to get past sometimes. But, I guess if it's worth doing it is worth doing twice.

David, I think it'd take more than a heartbeat to read it though. For me sometimes it takes hours or even days before some of Dan's writings sink in. Not too many people put that kind of serious thought into what they do.

Jim

"David, I think it'd take more than a heartbeat to read it though."

I haven't been the same since I took that Evelyn Wood reading course.

Dan must have hopped up his typewriter, as well. ;)

> Dan must have hopped up his typewriter, as well. ;)

The sad thing is I never learned to touch type. I have worked
up from two to four fingers though :-)

Dan Jones

Oh, my shame...I used to type in high school.43 wpm. Of course back then, for Phys. ed, they'd cut T Rex loose, to chase us around. Whoever survived, got a passing grade. Perhaps the message is, use it or loose it ? roverman.