Which car are you referring to?

 

Yeah, except the cannon is 0.25 miles long. Form follows function...that's a sweet look'in bird. I have always wondered what it must feel like when you can't see the ground in front of you on the way to 100 mph.

 

Yup, that's what it was designed for...a street-legal, component-built, Chevy-powered, tube-chassis road-race car.

 

Who is putting this engine together?

 

Ha! Not me!!! I have a friend that has only worked on Corvettes since 1975. Vettes are his life. He has offered to help me build the engine. He builds a couple a year for his personal project cars and a couple a month for his corvette customers.

I have been reading forums and books (about 10 now) for the last few months and hope that I can contribute to the assembly process...as well as suggest logical choices for dependable components to reach the power goals. I know there is no replacement for actual experience, so I would not try to build this myself. Besides, it would require an investment in engine-building tools as well.

 

I just read this thread and I had asked a similar question to mikey from Rapid Motorsports a few days ago. I was talking to him about building a solid roller motor versus a hydraulic motor because I thought the same thing about spinning the hydraulic lifters to fast and causing problems. Here is his response:

"Why do you want a solid roller? The reason I ask is that we are doing a hydraulic Morel based 402 LS2 that I fully expect will put down close to the numbers you spec'ed (Which were around 550rwhp). It used to be that we ran solids because of the lifter bleed at high rpm. Morel has solved this with their lifters."

So it looks like the new technology may have narrowed the gap betwenn solid and hydraulic motors. Hydraulic may be the way to go. I would suggest calling or pming an engine builder like mikey from rapid or Allan at Futral or any other sponsor for that matter and talking to them.. Those guys are the ones that are up on the best way to do things. Regardless it should be a sweet setup the Ultima is an AWESOME platform!!

 

Yes, the Ulitma will be very sweet...when I get done! I want to make the right decisions with it, but am also anxious to get started. An RX7 with a juiced LS1? Cool!

I will talk with more engine builders. Of course, there are many knowledgable folks on this board and it's my opinion that some (that have built their engines or had them professionally built for them) have responded to this thread. I just learned of Morel lifters (couple of posts back), but haven't found their Website yet. If anyone has it, please post up.

It's possible hydraulic could handle those revs, but, as far as I have read, it's not just the RPM that causes the problems with hydraulic lifters; it's the combination of RPM, spring pressure, and lift. With high revs, tall lift and heavier spring pressures (needed for lift), the lifter "pumps down". The oil is pushed out and you have a "dry lifter", which causes the valve to rattle up and down -- out of sync. The valving in the lifter doesn't have time to reset and retain oil. This apparently happens between 300-400 lbs and 6k to 6.5k RPM with higher-lift cams.

However, if there's another solution, nothing is purchased yet and I can consider all options. Although the spreadsheet is started with a quite a few selections, it's easy enough to change.

That said, building an engine can be 'lot like buying/building a computer. As soon as you buy it, it's obsolete. Something new comes out with better performance. Continuing the computer analogy, it's also important to use proven technology when the application is "mission critical". And I consider the Ultima's engine performance as such. I will be considering that when looking at Morel's products, as it's possible they have only been around for a few months?

Lastly, I don't want to run any given engine component above 85% of it's duty cycle. If I want the engine to spin to 7500, the lifters (and everything else) should be able to handle 15% above that, or I will be needlessly testing the manufacturer's quality control to the limit and opening the door to premature failure.

I really appreciate the comments, folks. Thank you for taking the time to share your knowledge and experiences.

 

For cars driven on the street, I believe that hydraulic is the way to go. Just to give you a little more perspective, W2W made over 1300 hp with their turbo motor and hydraulic cam. Why screw with the maintenance?

 

I hear'ya. Wonder what RPMs they were turning. Still nothing cast in stone, so I will find out what Morel has. BTW, just spoke with Scott at Morel Motorsposts (Gear Company). He referred me to their sales guy. You will never guess who that is (read: high-profile). I will post the results, which should be very enlightening...

 

Kurt posted the dyno sheets and seems like peak rpms were around 7200.

 

As unopinionated as I am about the components (brand names) that will go into my engine, I have to listen closely when someone with decades of vast experience takes the time to share their thoughts on what I am putting together.

I had the pleasure to speak with a guy who was the chief valve train designer for GM, built GTP cars for Daytona and Le Mans, and who started a very successful automotive manufacturing business; Mr. John Callies.

John said they are currently building lifter sets for NASCAR engines and that the reason many people don't know the name "Morel" is due to the large private lable business they have.

He said one of the toughest environments for engine testing is boat racing due to the long periods of WOT application and over-speed conditions when the props come out of the water (and back in). They ran their latest test lift at 0.657" and got in excess of 120 hours at a max of roughly 7600 RPM. These were very special lifters and very expensive.

When I told him of my specific goals, and the counterpoints on this board, he said, "Let me clear this up for you. Go solid roller." He said with the durability required in a road-race engine, it's the best way to go. John said generally available hydraulic products are good to 0.630 to 0.640 lift, but be careful above 7k RPM. So, with less lift, you could turn more revs, but that is the upward limit of hydraulic (piston) lifters.

Who am I to argue?

The newest solid-roller products will be very slick. John was a most gracious gentleman, and I didn't even really expect a call back...let alone in the same afternoon.

So, that ends the debate for me. I am sure there are folks who have had good experiences with hydraulic lifters and 7k+ RPM, and I would still like to hear about them. But, I am definitely going with the solid-rollers.

Thank you all very much for your valuable comments. I might not have learned of Morel Motorsports without this board.