Oct 26th, 2017

Precise balance correction of a Copen JB-type crankshaft was done today.
A 4 cylinder for a Kei car (Japanese category for small cars) is very special, they are typically 3 cylinder cars.
This crankshaft was produced by casting.
Cast iron cranks are particularly great as they barely bend at all.
We always check to make sure there is as little distortion with the balance as possible.

This time we treated the final surface treatment with manganese phosphate, this reduces sliding resistance and reduces wear.
The image shown is the result of the surface treatment.
After this, we will work on polishing the journal.

NISSAN VQ37 Cylinderblock

Oct 25th, 2017

Today we are looking at a VQ37VHR cylinder block for a Fairlady Z34.
We’re working on remodeling the water jacket , installing a dummy head, as well as boring and honing the cylinders.
Although the number of engines is still small, our company takes care of various tasks.

We will introduce it at a later date, but our company also offers the BIGVALVE, our very own original part.
As there is room for thickness of the seat ring, we install a large valve for greatly increased performance.
Although it uses a VVEL system, if carefully planned and executed, there will be no issues with it functioning properly.


Oct 23rd, 2017

This 7MG engine is now complete.
To our customer, sorry to keep you waiting. The head cover is the strongest pink, just as requested.
It is the same shade of pink that our company logo uses.
We also have pink NAPREC T-shirts which were made last year, it’ll match nicely.

The parts for this very special engine have undergone WPC processing and have friction reduction.
The initial startup is important for high performance and a long lasting engine. Please ensure you put in the best engine oil possible and turn the oil really well before starting her up.
We’re excited to see it run!

Only thing left for us to do is pack it in a wooden box and send her off!

Welding type Oil pan

Oct 21st, 2017

Today we’re welding together an aluminum oil pan for a 6 cylinder engine.
The weld structure is processed using a sharpened block mounting flange and the back and surface are firmly welded.
It will not be annealed, but it is a very firm weld.

After this, we will finish the flange surface and the work is complete.


Oct 07th, 2017

Today we’re tending to the wounds of a FERRARI 308 by weld repairing the cylinder head which has a crack in the combustion chamber.
We will perform checks, pre-welding treatment, then laser weld by melting with light and welding it as shown in the image.
Of course, after this we will perform a pressure check to confirm there are no leaks.

There have been many repairs similar to this as of late.
The engine that has had the most crack repairs is the Nissan S20.
We still have 6 head crack repairs to tend to after this.

日産GTR VR38DETT CylinderHead

Sep 29th, 2017

We’re working on a VR38 cylinder head today.
This time we’re going to do some CNC porting and processing the CNC combustion chamber.
The crank shaft has been rebalanced, and the valve seats will just get a cut, but we’re sure it’ll be a great finish.
I can never get tired of looking at these engines…

TOYOTA 2JZCylinderblock

Sep 25th, 2017

Several Toyota 2JZ’s have been assembled.
Many billet crankcaps are also being processed.
We want to get all these out by the end of September, so we have our work cut out for us.
Still have to make those dummy heads for the blocks, gotta kick on the turbo!

Lamborghini Diablo V12

Sep 23rd, 2017

We’re working on fixing up this guy today, the Lamborghini Diablo V12 cylinder head.
This engine had a cam line failure, and we’re going to be making new caps for it.
The image shows the engine about to undergo line boring. Since the diameter is small, we’re being extra careful with this one.
The thrust surface also looks banged up, so we’re going to fix up the end face as well.
We talked about cam caps in an oder blog, but they’re made through designing them in 3D-CAD and CADCAM, then cutting them out.

PORSCHE911 Cylinder

Sep 21st, 2017

Today we’re working on the inner diameter of the air-cooling cylinders for a Porche2.7. We’re honing to adjust the piston clearance.
At Naprec, we also work on honing Nika Gill cylinders, so we do this type of work on occasion.
We perform the honing by creating a dummy head and crank case and joining them together.

Pretty much all cylinders of Porsche air-cooled engines have nicadil plating treatment with the exception of a few models.
Nicadil plating is a process developed by the company Mare.
The plating has excellent harness and is also a great oil-containing surface. It is an ideal plating option for internal combustion engines and is also able to be processed directly on an aluminum surface.

I would like to alter domestically produced engines to aluminacadylate.

Mini Engine

Sep 20th, 2017

Today we are looking to adjust the valve timing for a MINI1000, a type of engine we work on very often.
This particular MINI has a 280° profile.
The cam shaft looks like it would be a lot of fun with a large working angle and lift.
We don’t get to work on cam shaft profiles very often, I wish we could do more of these.