I'm running a 4V motor with single turbo, air/water intercooler on a jet boat. I can run 3800 rpm easily for 30 min. I am rebuilding this engine w/forged crank, rods and pistons. The valve guides and piston to cylinder clearance will be a bit larger per spec for a marine engine. My question is, does anyone know what else I should do internally to run at 5000 sustained for 15 minutes. With the AA impeller in my boat, that would be around 85-90 mph. This would also be loading about 10psi of boost. The intake air temps are around 54* due to cold river water running through intercooler.

Thanks in advance,
John

 

I would definitely run a good size remote oil cooler setup if you aren't already, same with engine coolant. Keep the temps normal and it should be good I imagine

 

For sustained running, it's the details that matter more than anything ( on any motor regardless of use ).

Getting everything balanced and blueprinted to the nth degree, including the parts aft of the engine.

Controlling the harmonics in the engine and drive system. Find the best harmonic balancer on the market for the mod motor.

Barrier coat the pistons and bearings just to be safe.

Stud everything.

Upgrade the oiling system.

Upgrade the chain tensioners, and any other parts of the cam drive as needed.

 

Some time ago -Panoz-Elan- built a GT-2 Modular Ford 5.0 Liter

Panoz Motor sports offered up the challenge, could the Ford 32 valve modular V-8 be developed to compete against the most established racing manufacturers in the world: Porsche and Ferrari? In three short years, the Panoz Esperante and Elan Power produced shocking results with American Le Mans series wins: 12 Hours of Sebring GT-2 wins, and the crown jewel with team LNT, GT-2 winner of the 24 Hours of lemans.

Engine featured:
◾Factory Ford produced head and block castings
◾Elan low friction cylinder liners
◾Original equipment, forged, rolled fillet crankshaft with extensive lightening and counter weight phasing for extended high RPM use
◾Carrillo rods with DLC coated Del West wrist pin
◾Original equipment cylinder heads with extensive port development and lightening
◾Elan designed barrel throttle with proprietary castings and carbon fiber runners
◾Bosch MS 4.0 engine management system with active detonation control, flat shift, and lateral G sensitive traction control.

This was on a dry sump oil system setup & Jesel valve train

http://www.drysump.com/Fordmodular4.6.htm

http://elangroup.com/index.php?option=com_content&view=article&id=62&Itemid=58

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What he said, and I'll raise it one more..........

The Koenisegg sport cars all are powered by engines that started as Ford 4V modulars. The latest versions like the Agera R, Agera S and the One:One are some of the fastest and most capable hypercars in the world. Even though the engines are completely their own manufacter ( they cast their own blocks, heads and make their own hardparts ), in the beginning they used Ford's stuff.

 

What he said, and I'll raise it one more..........

The Koenisegg sport cars all are powered by engines that started as Ford 4V modulars. The latest versions like the Agera R, Agera S and the One:One are some of the fastest and most capable hypercars in the world. Even though the engines are completely their own manufacter ( they cast their own blocks, heads and make their own hardparts ), in the beginning they used Ford's stuff.

Do a look up on them also, they know how to make a twin turbo Mod run.

 

Oops, duplicate post, sorry.

 

Thanks for all the replies. I'm gathering that my key after blueprinting will be oil temp. I guess I ask because a car at 5k on a flat road for hours is not loading the engine. But in a boat at 5k, the engine is under Max load, ie no coasting or rolling.

 

Yeah, especially with all aluminum engines things move around a lot in the structure. Are you racing this boat or do you just want the margin?

 

No racing. I want t be able to keep up with my friends in their 38' twin big block boats when we're running down the river. There are some stretches that are 30miles between no wake zones. They cruise about 60-70 usually.

 

I know in sustained stress apps like this you have to have heavy, strong and overbuilt everything to be good.

 

Coyote in a carbon fiber jet boat with 2,500 hp intercooler. Engine is sleeved and with GenII 6466 Precisions turbos...

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Sexy beast, mmmm, mmmm, mmmm.

 

Ok, that's a beautiful engine. Great ideas for mounting the turbos and intercooler on the rail. My Young blood isn't carbon fiber, but it weighs in at a "Heavy" 500lbs. 19' Gullwing hull.

 

Did you say your hull is 500 lbs?

Oof, with 500hp at the prop she must be fun!

 

The new hull I picked up in Jan is 500lbs. That is a "Heavy" Lake hull in the company's opinion. They make same hull as low as 350. The 500lb is what I'm building the engine for and will be pushing 700net hp. Right now running 500 HP in a much heavier and run "wetter" hull. Still fun tho.

 

A lot of good points so far. One issue with long duration high RPM is piston heat soak. You really should consider piston squinters. That, more than anything else, will help stabilize the pistons. Also, make sure your piston manufacturer is aware of your intentions. They may want to control expansion with a certain alloy or build in extra clearance. With that infinite amount of constant temp cooling water put to good use with a properly sized heat exchanger you should have no problem. Needless to say your aluminum block will expand quite a bit so bearing clearances are critical and may need to be set a bit tighter than normal. Yeah, I know everybody is going to say that is nuts and high RPM needs more clearance. But when the block heats up, the clearances will increase to unacceptable limits. If you tighten up the main bearings an engine pre-heater is required.

 

Well, the engine will be built sooner than I had expected. I was running the stock engine this weekend and started getting tons of blow-by. I am taking block apart tomorrow and getting it to machine shop. Yes, in a marine application the pistons need a slightly larger piston to cylinder clearance and the valve guides need a slightly larger clearance. Once the block has been measured, I will order pistons. My next order of business is should I run a vacuum pump. I have read that MMR has run drag cars without a pump, but they do not run 15-30 minutes at 8-14lbs of boost. I have my alternator mounted up high-center and a single belt without a tensioner that goes from crank pulley to alternator. I would rather not have to run anything else belt driven. Any suggestions on yes or no on vacuum pump and if yes, on an electric pump such as an electric smog pump etc. One more question, I will be running pump (91 Octane) gas, should I run 8.5:1 or 9:1 compression? I get intake air temps of 54*-58* from constant supply of cold river water through an extremely large air/water intercooler designed for 1500hp.

Thanks

 

The 4V has a really good chamber, and since you have those cold intake temps you can get away with more SCR. Are you doing anything with the crown design with the new pistons?

Take a look at Microblue Racings coatings, I am going to get my bearings and rings done for my Poly, also the cam and lifters to reduce the friction and take some of the heat out. Couldn't hurt.

 

Yes, do evacuation of some kind. But you should be running a dry-sump and if done right that will be enough evacuation to make a difference. IMHO I would run 8.5 and add boost or try things out with your current boost and then add boost! 9:1 CR limits your options. With your wonderful supply of cooling water and your killer intercooler you are drastically limiting your options on boost with the higher CR. Boost, not higher CR is going to give you the most tuning flexibility and performance potential. CR is an efficiency thing but you don't care about that do you!

I thought boats ran wet headers? With the turbo are you running dry and hot headers?