Category: Tech Tips

Categories: Factory News, Latest posts, Tech Articles, Tech Tips

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There can be an argument for Either  –  Some further Questions we Typically Ask………

Do you have a limited budget?

The old standby Carb has been around forever, and there is something to be said for simplicity and Cost . If after a few years you wanted to Convert over to EFI its do-able.

Are you more of a Weekend Warrior?

Cruise locally or maybe layout some rubber. A carbureted engine may work just fine for you.

 Plan on Long cruises to Car shows or maybe go on the Power tour ?

EFI Certainly can have advantages with fuel mileage, consistent throttle response and adaptability.

What is climate like where you drive your car?

Extremely Cold or Hot Temps EFI adapt with the ideal Air Fuel Ratio.  Not to say a Carb engine wouldn’t run but, may need some tweaking being that its fixed mechanical device.  Some extra pumps at cold start up or very hot days fuel vapor lock.

Do you drive in High Elevations?

Driving in High Elevations like the Rocky Mountains typically higher than 6000 feet ABSL  tricks the carb in running more rich being that the air is thinner especially if it was tuned at sea level.  Re-jetting can solve some of these problems but uttimately the aftermarket EFI  we install will adapt this automatically with the ECU and O2 Sensor.

What are your Mechanical hands on skills?

A Carbureted Turnkey engine is less  install time initially. Some are still intimidated with installing fuel injection but the aftermarket has made things easier, plus we clearly label things so its pretty straightforward to plugin. Probably one of the biggest jobs of EFI is the plumbing of the fuel lines to the engine and installing the 02 Sensor Correctly.

There are a lot of EFI Systems on the market, which one is best for my vehicle?

We have used a number of EFI aftermarket Systems – MSD, Holley, EZ-EFI,FI-Tech, Edelbrock. Each company makes there claim to why one is better than the other.  We have had a lot of success with the Atomic EFI.  Less wiring than others, can run fuel returnless (not in all cases),  integral ECU, on the fly handheld wizard.  Engine Factory tests each setup on your custom crate engine to verify all the readings are within specs.  See video sample

 So to sum it up:

If you fall in the category of Occasional Weekend Warrior & on a Budget –  One of our Carbureted  Engine packages  may do the trick!

Longer Cruises,  Different Elevations, Extreme Hot or Cold Climates.  –  Go with one of our EFI Engine Pkgs.    Crisp throttle response, Consistent Torque, Fuel Efficiency, Adaptability,  Modern Technology


Categories: Latest posts, Tech Tips

Which Starter fits a Ford Small Block T5/TKO Conversion?

High Torque Starter
High Torque Starter

Which starter to use is a common question and a common source of frustration for people doing a T5 or TKO conversion behind a Ford Small Block. The problem stems from the mis-information in the literature and from the starter manufacturers themselves. It was, and still is, very common to read that you need a starter for a manual transmission (M/T).

But this is not enough. It really depends on the flywheel size being used. Small block Fords (260, 289,302,351w, 351c, 5.0L) can except either the 157 tooth or the 164 tooth flywheel with the corresponding bell housing. Early Mustangs were mostly 157 tooth, but some were 164 tooth, as well as, other Fords and trucks.

157 tooth flywheels in front of both the automatic (A/T) and the manual transmission used the same starter. This same starter was also used with the 164 tooth automatic transmission. It is only the 164 tooth in front of a manual trans which used a different starter (3/8″ depth).

It is this starter that people end up with which gives them grief. The local parts store may call out this starter as the starter of choice for a “manual” transmission. They don’t differentiate the flywheel.

So it is best to specify a starter for a “automatic” transmission as you will be using a 157 tooth flywheel in the majority of T5/TKO conversions. If you are using original bell housing and it is for a 164 tooth flywheel then you will need the 3/8″ depth starter (see chart).

The Details
As seen in Powermaster’s “Ford Starter Tech Bulletin” there are 2 critical dimensions, the diameter of the registration hole, and the depth of the ring gear.

Ford Starter Depth

Ring Gear Depth Registration Diameter
164 tooth, M/T 3/8″ 4.130″
164 tooth A/T
157 tooth M/T & A/T 3/4″ 4.084″
So what are our recommendations?
Starters 157 tooth M/T & A/T
164 tooth A/T 164 tooth M/T
Ford Racing High Torque M-11000-B51 M-11000-MT164
Power Master 3124/9162/9103/9603/9503/9403 9604/9504/9403
Tilton 54-10013 54-10018


Categories: Factory News, Latest posts, Magazines & Media, Tech Articles, Tech Tips

stroker Illustration


On virtually all engines, the intake valve stays open after the point where the piston starts up on the compression stroke. Until the intake valve actually closes, compression is not occurring and the true compression stroke does not start until it does. Because the cylinder volume is reduced, so is the dynamic compression ratio. The later valve closing takes advantage of air velocity at higher engine speeds to help fill the cylinder. At low speeds, yes, that reduces the effective compression ratio, but at higher speeds the increased volume of air more than makes up for it.



When we did a trial assembly of the stroker parts in the stock block, our deck clearance was 0.045 inch. We ended up removing 0.020 inch from the deck. Different aftermarket pistons have different pin heights and therefore different deck heights. Installing one piston and measuring your deck clearance to calculate the final compression ratio could save you heartaches later.

Decking the block can be an important step with a stroker. It has to do with quench height. The best idea is to deck the block for a zero deck height and a 0.040-inch quench height, but you must increase the combustion chamber size, either by enlarging the combustion chamber in the head or increasing the piston dish size. Don’t do it unless you have calculated the effects and have the right parts. Here, 0.020 inch is being removed from our block.
We were shooting for an SCR at or slightly below 10 to 1.  We measured the volume of the combustion chambers in the head. You can measure the dish separately, but in the cylinder, you also see the ring land volume (generally about 1.1 to 1.3 cc). We used the thinner of the two commonly available head gaskets, and after taking about 0.020 inch off the deck for a clearance of 0.025 inch.
The big question now is, “Why does this matter?” The bottom line is that the DCR is a major factor in whether you can run on regular, midgrade, premium, or race fuel, and not ping. Also, if the DCR is too low, you will lose bottom-end torque.

The next step is for you to determine what parts will give you the right SCR to match. If you can’t find the right mix of parts for the job, the easiest route is usually a longer-duration cam.

You can get a rough idea of what your compressed dimension will be by measuring the thickness of the gasket body (not the flame ring around the bore or sealing strips imprinted on the body) and deduct about 0.005 inch. This applies to the gaskets advertised as “permanent torque” or “no-retorque.” Cheaper gaskets that require retorquing can compress two to three times that much and are less predictable. Bottom line, you cannot say with certainty that X gasket has Y thickness unless it’s a performance gasket that has a listed specification.

Quench is the “Great Equalizer” when it comes to a high compression ratio. The quench area is the area between the highest flat spot on the piston and the lowest part of the roof of the combustion chamber. Less quench distance induces more turbulence in the combustion, which promotes better fuel mixing and fewer hot spots-all of which reduce pinging. Many experts think that 0.040 to 0.045 inch of quench is ideal,


To Get Deck Height (DH)
deck height = block height* – rod length – piston pin height – 1/2 stroke

To Get Compression Ratio (CR)
CR = total cylinder volume combustion chamber volume

To Get Combustion Chamber Volume (CCV)
CCV = cyl head volume + head gasket volume + deck clearance volume + piston dish volume

To Get Cylinder Volume (CV), Deck Clearance Volume or Head Gasket Volume
CV = 0.7853942 x bore2 x stroke
Note: For head gasket, used compressed distance.

To Get Quench Height (QH)
QH = deck height + head gasket compressed distance
*Block height = Distance from crankshaft centerline to block deck



Categories: Customer Rides, Factory News, Latest posts, Tech Tips

Understanding Camshaft Specifications


Lift refers to maximum valve lift. This is how much the valve is “lifted” off its seat at cam lobe’s highest point.

How does it get measured?

Cam Lobe Lift Valve Lift is the amount (usually in inches) that the valve is lifted off of its seat. It is usually measured with a dial indicator at the tip of the valve. Lobe Lift is the amount (usually in inches) that the cam lobe increases in radius above the cam base circle.

Tip: To quickly find maximum lobe lift, measure the base circle of the cam and subtract it from the thickness across the cam lobe’s highest point (see the diagram below).

Tip: Maximum valve lift can be calculated by multiplying the maximum lobe lift times the rocker ratio. For example, a 0.310″ lobe lift cam yields 0.496″ of valve lift when using a 1.6 ratio rocker arm.

Formula: valve lift = lobe lift x rocker ratio

What does it do?

The intake and exhaust valves need to open to let air/fuel in and exhaust out of the cylinders. Generally, opening the valves quicker and further will increase engine output. Increasing valve lift, without increasing duration, can yield more power without much change to the nature of the power curve. However, an increase in valve lift almost always is accompanied by an increase in duration. This is because ramps are limited in their shape which is directly related to the type of lifters being used, such as flat or roller.



Duration is the angle in crankshaft degrees that the valve stays off its seat during the lifting cycle of the cam lobe.

How is it measured?

Advertised duration is the angle in crankshaft degrees that the cam follower is lifted more than a predetermined amount (the SAE standard is 0.006″) off of its seat. Duration @.050″ is a measurement of the movement the cam follower, in crankshaft degrees, from the point where it’s first lifted .050″ off the base circle on the opening ramp side of the camshaft lobe, to the point where it ends up being .050″ from the base circle on the closing ramp side of the camshaft lobe. This is the industry standard, and is a good value to use to compare cams from different manufacturers.

What does it do?

Increasing duration keeps the valve open longer, and can increase high-rpm power. Doing so increases the RPM range that the engine produces power. Increasing duration without a change in lobe separation angle will result in increased valve overlap.



Lobe separation is the angle in camshaft degrees between the maximum lift points of the intake and exhaust valves. It is the result of the placement of the intake and exhaust lobes on the camshaft.

How is it measured?

Cam Lobe Separation Lobe separation is usually calculated by dividing the sum of the intake centerline and the exhaust centerline by two.

What does it do?

Lobe separation affects valve overlap, which affects the nature of the power curve, idle quality, idle vacuum, etc.



Overlap is the angle in crankshaft degrees that both the intake and exhaust valves are open. This occurs at the end of the exhaust stroke and the beginning of the intake stroke. Increasing lift duration and/or decreasing lobe separation increases overlap.

How is it measured?

Overlap can be calculated by adding the exhaust closing and the intake opening points. For example, a cam with an exhaust closing at 4 degrees ATDC and an intake opening of 8 degrees BTDC has 12 degrees of overlap.
Keep in mind that since these timing figures are at 0.050″ of valve lift, this therefore is overlap at 0.050″. A better way to think about overlap is the area that both lift curves overlap, rather than just the crankshaft angle that both valves are open. Therefore, one can see that decreasing the lobe separation only a few degrees can have a huge effect on overlap area.

What does it do?

At high engine speeds, overlap allows the rush of exhaust gasses out the exhaust valve to help pull the fresh air/fuel mixture into the cylinder through the intake valve. Increased engine speed enhances the effect. Increasing overlap increases top-end power and reduces low-speed power and idle quality.



The intake centerline is the point of highest lift on the intake lobe. It is expressed in crankshaft degrees after top dead center (ATDC). Likewise the exhaust centerline is the point of highest lift on the exhaust lobe. It is expressed in crankshaft degrees before top dead center (BTDC). The cam centerline is the point halfway between the intake and exhaust centerlines.



Cam Advance and Retard Advancing or retarding the camshaft moves the engine’s torque band around the RPM scale by moving the valve events further ahead or behind the movement of the piston. Typically, a racer will experiment with advancing or retarding a cam from “straight up” and see what works best for their application. Lunati camshafts are ground to provide maximum performance and are designed to be installed to the specifications listed on the cam card.

How is it measured?

A cam with a 107 degrees intake lobe centerline will actually be centered at 103 degrees ATDC when installed 4 degrees advanced.

Most Lunati camshafts have a certain amount of advance ground in. “Ground-in advance” can also be found by subtracting the intake lobe centerline from the lobe separation.

What does it do?

Advance improves low-end power and response. For a general summary of the affects of camshaft timing, refer to the following tables:


begins intake event sooner
opens intake valve sooner
builds more low-end torque
decreases piston-to-intake-valve clearance
increases piston-to-exhaust-valve clearance
delays intake event
opens intake valve later
builds more high-end power
increases piston-to-intake-valve clearance
decreases piston-to-exhaust-valve clearance