914-6 Biral cylinders

[Turboman]

I own my 914-6 for about 27 years, we did a top end overhaul about 15 years ago, and now is time for a serious complete overhaul.

Is not going to be my first Flat 6 engine overhaul but it will be my first 2 liter overhaul. I took out of Wayne s and Bruce s books and read all about 2 liter engine, procedures and possibilities.

Still have a doubt.

I want to increase the power of my engine, via S cams, better heads, a 964 oil pump, oil sqirters, and new pistons and cylinders.

On the market several companies offer 86mm JE pistons with Biral cylinders. Wayne and Bruce hardly comment on Biral Cylinders. I know Nikasil will be the top, but Nikasil cylinders + pistons are about 3 times more expensive than the Biral cylinders + pistons.

Do you think for a street use, fast street use, the Biral can be a good choice, or I need Nikasil if I want to keep my engine for another 3 decades.

Thanks in advance for your comments

Francisco

[Henry Schmidt]

Originally Posted by Turboman

I own my 914-6 for about 27 years, we did a top end overhaul about 15 years ago, and now is time for a serious complete overhaul.

Is not going to be my first Flat 6 engine overhaul but it will be my first 2 liter overhaul. I took out of Wayne s and Bruce s books and read all about 2 liter engine, procedures and possibilities.

Still have a doubt.

I want to increase the power of my engine, via S cams, better heads, a 964 oil pump, oil sqirters, and new pistons and cylinders.

On the market several companies offer 86mm JE pistons with Biral cylinders. Wayne and Bruce hardly comment on Biral Cylinders. I know Nikasil will be the top, but Nikasil cylinders + pistons are about 3 times more expensive than the Biral cylinders + pistons.

Do you think for a street use, fast street use, the Biral can be a good choice, or I need Nikasil if I want to keep my engine for another 3 decades.

Thanks in advance for your comments

Francisco

Be careful with some of the aftermarket cylinders.
The cast iron on many of the Chinese cylinders is considerably softer that their German counter parts. The other thing with some of these cylinders is consistent sizing.
We like the pricing as well so in an effort to make something cost effective and still high enough quality to feel comfortable using, we are taking the Biral cylinders and having them Nikasil coated (Nikasil coating cast iron is an old NASCAR trick). This accomplishes two objectives. It creates a more consistent sizing and creates a bore that can withstand the challenges of an air cooled performance engine.
The last two engine I built for my own use were 2.45 liter built using 70.4 (2.4/2.7) crank and 86mm cylinders with this treatment. They had Mod "S" cams, 40 mm Webers, 9.5:1 compression and 36 mm ports. The engines made 180 RWHP and incredible low end driveability.

[ravi1]

I want to increase the power of my engine, via S cams, better heads, a 964 oil pump, oil sqirters, and new pistons and cylinders.

On the market several companies offer 86mm JE pistons with Biral cylinders. Wayne and Bruce hardly comment on Biral Cylinders. I know Nikasil will be the top, but Nikasil cylinders + pistons are about 3 times more expensive than the Biral cylinders + pistons.
Untitled Document

Do you think for a street use, fast street use, the Biral can be a good choice, or I need Nikasil if I want to keep my engine for another 3 decades.

Thanks in advance for your comments

[ravi1]

We like the pricing as well so in an effort to make something cost effective and still high enough quality to feel comfortable using, we are taking the Biral cylinders and having them Nikasil coated (Nikasil coating cast iron is an old NASCAR trick). This accomplishes two objectives. It creates a more consistent sizing and creates a bore that can withstand the challenges of an air cooled performance engine.
The last two engine I built for my own use were 2.45 liter built using 70.4 (2.4/2.7) crank and 86mm cylinders with this treatment. They had Mod "S" cams, 40 mm Webers, 9.5:1 compression and 36 mm ports. The engines made 180 RWHP and incredible low end driveability.

[Turboman]

Henry, appreciate your comments, liked your web site, impressive.
If I use 86mm Biral/Nikasil cylinders, knowing the 2 liter cylinder heads are not the best, would you recommend 2.7 liter cylinder heads over 2.4 liter ?
Thanks
Francisco

[Henry Schmidt]

The 2.0 head can be machined to work and for some, the small valves offer some benefit.
In the early days, we built 2.5 engines with the 2.0 heads (mostly 914/6) that performed very well.
That said: On a carburetor 86mm engine, I like to use the 2.2 "T" heads.They offer the improved valve angle together with improved chamber shape. They also have small ports so porting is open to preference (matching the cams and compression) and the chamber perimeter is closer to 86mm. That allows you the chamfer the head chamber to match the cylinder bore.
2.7 heads generally have a chamfer to match the 90mm bore which makes them less desirable for the 80-86mm conversion.
There are some early 2.7 heads with the correct (84mm) chamber but they tend to have more value.

[Turboman]

Henry, I want to ask you an extra question. I have on my 914-6 the 2 liter heads. I can also buy 2.2 liter heads for about 500 Euros (the six). It worth the investment, or not and I better use my hard earn euros on other areas?
Let me thank you again, I know you take time of your business to answer questions.
Francisco

[Walt Fricke]

I assembled a 2.3 race motor (66x85) using bored out Porsche Birals. Worked just fine. I didn't know about the old Nascar trick of Nikasiling them, and that technology wasn't as wide spread then either (mid-90s). Didn't get to learn about longevity because the stock rod bolts (all that was readily available then) weren't up to 8,000 rpm over the long haul.

The Birals worked fine for street Porsches of the day, so if you have them, why not? If you don't, other options are there for you.

The 964 oil pump won't increase your power. In fact, it will decrease it, as pumping more oil draws off a more of the engine's power available to turn the wheels. You don't need one - a 3.0 or 3.2 pump will do the job. Of course, if you don't need to save $, or already have one, more oil gives one more confidence in longevity.

[JmuRiz]

Henry, I wrote you a couple weeks back with the following:

Where can you get stock cyls re-plated? Is this something you do via a sub contractor, or can we contact them directly?
I plan on having mine rebuilt and if the cyls (2.7) are in good shape, would it make sense to do the above rather that buying a set of budget cyls/pistons as a package (aa cyls)?

If the stock cyls are in good shape, can they be coated in Nikasil and be good as new w/o having to buy new cyls?

[Henry Schmidt]

Originally Posted by JmuRiz

Henry, I wrote you a couple weeks back with the following:
I guess your inquiry got lost in the hundreds of email I get daily, sorry.

Where can you get stock cyls re-plated? See below Is this something you do via a sub contractor, or can we contact them directly?
Depending on the size, we have them in stock at 911 Vintage Parts (760-731-4911)

I plan on having mine rebuilt and if the cyls (2.7) are in good shape, would it make sense to do the above rather that buying a set of budget cyls/pistons as a package (aa cyls)? If your pistons are nice, just replate your cylinder or get an exchange. If you want to go with JE pistons buy them from Pelican.

If the stock cyls are in good shape, can they be coated in Nikasil and be good as new w/o having to buy new cyls? YES

Millennium Technologies
1404 Pilgrim Road
Plymouth, WI 53073
Toll-Free: (888) 779-6885
Millennium Technologies LLC

[Turboman]

Walt, thanks for your comments, I do have a 964 oil pump on hands.
Francisco

[Henry Schmidt]

Originally Posted by Turboman

Walt, thanks for your comments, I do have a 964 oil pump on hands.
Francisco

The 964 oil pump is huge and does indeed offer a tremendous amount of oil delivery and scavenging but they are also prone to housing cracks. If you're fitting a used 964 oil pump, be sure to inspect the housing for cracks.
The 964 also offers another challenge and that is "what sump cover to use?".
Burnham performance makes a great alternative for just this purpose. Made in the US by a fellow Pelican (may be Pelican offers it) there was a great deal of thought brought to developing this product.