Darton cast liners

I have no idea who Darton is but the OE liners were the worst part of the 2 valve motors. I sure would not be buying those. They were cast as well BTW.

Steel liners did not come into use until the 355. Those are made by Mahle and are expensive.

 

There are several companies that make iron liners. I have just never heard of that one.

I just bore old liners and we leave them in place with a torque plate.


On QV motors I stick with alloy liners. They are a better cylinder.

 

I machine the blocks for Nick's large bore 308 engines using sleeves of my design I make at my shop using Darton ductile iron sleeve blanks. I just finished a 308 block this week and I will be starting on another next week, the long overdue 4 liter block for Mark Lewis.

Darton sleeves are not cast iron. They are spun cast ductile iron with tensile strength exceeding 100,000 psi. Common gray iron cast sleeves have a tensile strength one third of that number.

Darton supplies 100% of the teams racing in the fuel classes in NHRA because they have the best sleeve material on the market. They also supply most of the tractor pull competitors with liners.

That said, I work closely with Darton and am one of of the patent holders of their line of MID wet liners. I am also their sleeve installation center and do all their block R&D for new projects.

Any time you make an engine larger or modify it to produce more power, the cooling system needs to be upgraded. This holds true of any engine. This is the reason I came out with an upgraded coolant pump for the Ferrari which Nick sells. Nick also sells larger capacity drop in aluminum replacement radiators which I worked with an outside supplier to produce for Nick.

In any case, I machine the interior of the 308 block so coolant flow is not restricted. The Darton sleeve material is so strong the wall thickness can be reduced providing more room for coolant circulation than would otherwise be possible.

I recommend you check out the photos of block machining Nick has posted on his site so you can see what is involved.

The heads need to be modified to take advantage of the increased displacement. The stock 2V head is not up to the job. I did the 2V head development work and was able to increase the flow to a more respectable level. Still not up to modern cylinder head standards but capable of producing 350 hp at the flywheel with 3.5 liters with street able cams. Nick's 3.5 dyno run is still available for viewing on Carobu's web site.

Steve Demirjian
Race Engine Development

 

My 3 5 LITER does not run hot at all, it can sit idling and idling, no issues... We spent allot of time designing going through the weak points on the 308 engine design, myself knowing all of the weak spots of the engine spent time with Steve to do develop products that make our big bore engines reliable… no service intervals for a min of 90,000 miles with the exception of a possible valve adjustment. My engine is running cooler than a stock injected 2/ 4 valve engine with Marelli ignition. Using the Evans coolant was part of the design as it is very efficient, has no pressure, along with being a lifetime coolant it also does not cavitate and it is good form -40 to +375 Deg.

With the Forza water pumps & radiators along with the Evans coolant there are no cooling issues period…


http://www.youtube.com/user/NicksForzaFerrari?feature=mhum#p/u/14/8GbeoqQreTI

http://www.youtube.com/user/NicksForzaFerrari?feature=mhum#p/u/16/fqWjwMC2de4

Note, that the dyno results on Carobu’s site were preliminary, the person hired at the time to tune it on the dyno did not understand how the TEC 3 worked, he was tuning it as if it was a Motec plus the engine was running on 7 cylinders during that dyno test!

The Forza 3.5 liter & 3.93 engines have been designed to eliminate those Ferrari service intervals and expensive maintenance parts and is designed as a street engine that idles smooth to be driven on a daily basis. Here are some pictures of a block that is being done at this time for a client in Texas, this is a 3.5 liter, the next one on the schedule is a 4 liter using a custom crank and after that a 3.93 liter using a 360 crank.


Enjoy the pics!
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John, Is this a new project on a different 308? I thought that you completed your engine rebuild a few months back.

 

Nick , thanks for sharing .

 

Thanks guys!

 

Are the liners the same hieght as the deck?

 

We also replace the OEM cylinder head studs & nuts with a custom version made for us.

 

We are using original 360 cranks for the 3.93 liter engine, with the 3.5 that is in my car it is just a stock 308 crank. The 4.1 Liter that Steve is machining this week uses a custom crank made here in the USA. The price of custom high quality billet cranks has really gone up over the last 5 years so I decided to start using used 360 cranks, being that we have been making custom flywheels & clutch kits, it was less expensive to modify our clutch/flywheel package for a 3.93 using a 360 crank.

With these big bore engines we were more concerned in making the block stronger, making the engines more reliable and removing those service intervals. Ferrari cranks have always been stout, having Steve machine the blocks with the custom ductile Darton liners allows us to get a big bore engine that is much more stable and that runs cool.

The MLS gaskets are great as you can remove the heads, wipe the gaskets clean, copper spray them & re install them but you must have a block deck that is flat, the way that Steve does the blocks they are perfectly flat. Another cool thing is they can handle a whole lot of boost if done this way. Steve has some 3.5 liter Nissan EQ 35 engines making 2200 REAR WHEEL HP on methanol with 65 LBS of boost and they are staying together! We can make 1,000 HP on these 308 big bore engines and keep them reliable, the problem is the cost to do it.. Anyways, that’s my 2 cents worth for the day.

 

I would worry about the seal at the base of the liner. The stock liners .002" above the deck in order to have a proper crush on the base seal. Different set up?