Maruha's BP Camshaft Lines

We are happy to introduce Maruha’s upgraded camshaft lines.
Our camshafts the F-CAM lines, which so many users have enjoyed for a long time, will be upgraded as more user-friendly specifications.
The camshafts for BP engines, released at the beginning of the lines, are suitable for NA8C, NB8C and NB8C (with variable valve timing spec).

Billeting the material produces the new BP camshafts to make a wide variety of cam profiles.
Our products can match your needs.

The F-CAM for NA8C

The F-CAM for NB8C before M/C (without variable valve timing spec)

Making Maruha’s BP Camshaft

Maruha had spent much time and energy before the BP camshaft was released.
For instance, we had enhanced the product performance by repeated tests loading the trial models onto our chassis dynamometer.

1. Features of the F-CAM for NA8C (with HLA system)

To design a camshaft, we must consider its base circle firstly.
It forms the diameter of the camshaft round tail and the cam lobe means its additional lift.
The genuine NA8C contains the base circle of 36.0mm and sizes the maximum lift as 8.1mm(IN) or as 8.6mm(EX). Consequently, the top of the cam lift is rotating drawing the circle with the radius of 26.1mm(IN) or of 26.6mm(EX), from the center of the camshaft.

Whenever we check the genuine NA8C cylinder heads, different clearances can be found between the cylinder heads and the cam lifts.
Due to the clearance errors, caused by casting, even the genuine camshafts have insufficient clearances at full lifts.

Basically, when the lift with the 36.0mm base circle is increased, its top could rub against the cylinder head.

Maruha never hopes you to rub your eyes in disbelief. -“ Your car is messed up!” We produce our high lift camshafts with smaller-sized base circles.
They are designed with most the same maximum radiuses as the genuine cams.
Our quick attachment cams are suitable for the HLA (Hydraulic Lash Adjusters) system.

The most basic model F-CAM for NA8C specifications are as follows: Duration 252°/Lift 9.2mm(IN) and Duration 256°/Lift 9.5mm(EX).
The F-CAM lines are guaranteed to maximize their performance.
They achieve stable idle quality and smooth daily driving. And surely, you will realize the engine’s revving ability has been rapidly improving.

P5(図)

1. The high compression genuine piston for NB8C after M/C (0.25mm OS)
2. The upgraded F-CAM
3. The Freedom ECU without the stock air flow meter
4. The stock intake manifold
5. The refilled air cleaner
6. Maximworks Exhaust Manifold (with a catalyzer)

P6(graph)

2. Features of the F-CAM for NB8C (with inner shim)

A high lift valve consists of its enlarged duration and its high lift. For example, the genuine camshaft for NB8C before M/C (without variable valve timing spec) contains the lift about 9.0mm, though almost people pass by the existence of the genuine cam lift.

Well, EYES WIDE OPEN! Maruha will beat your fixed ideas. We have built up our cams in view of higher lifts as well as enlarged duration. Higher lifts than 9.0mm can lead to better high cam performances.

The F-CAM for NB8C, lift 10.0mm, is enlarged a valve curtain area to improve IN/EX performance.
The product features follow you a fantastic street drive with more torqueful and powerful performance.

Reading the news, you might be addicted to the F-CAM.
You do not need to adjust the valve timing and it is allowed to be adapted to the genuine camshaft pulley.
The genuine camshaft base circle is sized as 36.0mm.
We design the smaller base circle 33.0mm. The F-CAM smaller maximized radius and easy-attachment camshaft. Maruha’s solid lifter and our cap type shim are needed separately.

P7

3. Matching your tastes

Maruha’s F-CAM lines for street drives have been developed to give your great pleasure to drive.
Its duration is not much greater than the genuine camshafts’.
The F-CAM is a proudly elaborate product as a result of close observations, ceiling to floor data and huge time.

Have you had any trouble with the valve timing adjustment to attach camshafts?
The genuine camshaft pulley allows the pin position of the cam/rocker to apply our recommended value.
Surely, we are welcome to you who have your own way to adjust valve timings.
Maruha promises you to match our users’ tastes. The F-CAM lines accept to exchange head gaskets or to grind cylinder heads.

4. Floating-free inner shim

89-97 MIATA engines, adopted HLA (Hydraulic Lash Adjusters), need no maintenance. Since 1998, NB8C was released, the outer shim system has replaced it.
Outer shims work well at a high RPM engine.
It is no big deal in theory to product high camshafts with outer shims, but Maruha refused the sweet deal.

We put into practice the new specifications with solid lifters, examining the balance between the sizes of base circles and of lifts.
And without saying, we have to prevent outer shims from sliding out of lifters.
An outer shim on a solid lifter is in fact it is only placed on the lifter.
Shims, kicking out noisy HLA, have the advantage of fast valve movement.
It is possible to exchange the shims with the specified tools without replacing the camshafts.

Floated Outer Shims: Bad lifter settings or camshaft profile changes include the chance of floated shims.
They could lead a grave risk of dropping shims when you start cars.

Don’t you yawn reading every single line, huh?
Now then, let’s talk about our original lifter in question.
Our product, the F-CAM is adopted an inner shim which cap covers the top of a valve.
The lightweight solid lifter can increase RPM in safety.

Maruha recommends you to select the F-CAM.
It is a happier and wiser choice than the case you have to live with HLA, not working at high RPM, or with outer shims with fear of floating.

5. Finding the suitable length of the inner shim

The F-CAM for NB8C (the base circle 33.0mm), superior to the genuine camshaft (the base circle 36.0mm), improves the shim adjustment.
The radius of the product is 1.5mm smaller than the genuine one because of very precise machining.
Our product is elaborate designed in order that you can find its shim length easily, following the appropriate clearance of the genuine cam.
If you need the same clearance as the genuine one, we recommend you will order the inner shim, 0.2mm thinner than the thickness of the genuine outer shim.
Therefore, it can be estimated a rough size of what you need by taking 0.2mm from the thickness of the genuine product.

6. Stylish and lightweight specs

Do you believe the genuine NB8C outer shim is lighter than HLA?
NO! Actually, the weights between them have subtle differences because the outer shim has its heaviness and the top of the lifter is required strength.

Maruha’s F-CAM lines contain stylish and lightweight solid lifters.

7. Using the NB8C cams for NA8C

Because of NA8C with HLA, the NB8C camshaft is unable to be placed directly to NA8C. We recommend that you use our NB8C solid lifter set.

There is a cost savings tip.
The plunger should be removed from the center of HLA and you may press an appropriate collar into HLA.
Various valve lengths will make you adjust the valve clearances.
It is not a piece of cake, but your car with the high-speed camshafts gains more stable performance.

You can save costs by pressing collars.

The F-CAM, Maruha’s high-quality camshaft, has a 26.5mm maximum radius. In case of putting it on NA8C, it might be necessary to shave the edge of your valve lifter hole.

8. Cap type shim

The F-CAM shim, a cap type, should cover the top of the valve to attach to it firmly. If you place the shim to the center of the lifter side, there is a risk that it drops off while you work.

Our shim lines develop from 2.00mm to 3.65mm in 0.05s of millimeters.

9. Who is her soul mate?

Match Made in Heaven

The high-lift and gorgeous F-CAM has only one partner.
His name is the genuine valve spring!
There is a reason that we cannot defeat her sweetest boo.
The genuine valve spring does not include state-of-the-art design, but it acts as a tempered valve spring.
When Maruha examined the genuine ones, it became clear that they can work well with 10.0 or more millimeters cam lifts. Especially, the genuine NA8C BP valve spring with the maximum lift (IN 8.1mm/EX 8.6mm) can withstand loads of 62kgf(≒608N), and with a lift of 10.5mm, it forces up to 75kgf(≒735N).
The valve spring has ample strength to be used in safety.
If you are a NB8C user and plan to try a high rotation engine, the valve spring for NA8C will take you to an AWESOME drive!

10. Epilog

We have spent a large budget and long periods of time to produce the full-grown F-CAM.
As for us, this camshaft is an irreplaceable blessing.
If you enjoy our F-CAM lines, we provide them at reasonable prices.

Visit our F-CAM Page again and again, as we plan on increasing our lines of street performance F-CAM. We also produce the race-spec F-CAM. For more information, feel free to contact us.