Thinking of a LT4 swap - will it fit in a NB?
 

Anyone know if the LT4 is too tall of a motor (when you include the SC) to fit in a NB?

Also, anyone know what fuel pump would support that kind of power?

Thanks

Parker

Try it and let us know...

Figure it fit in a similar hole as an LS series engine, give it a try

According to information I have read the LT4 will not go into any Miata without doing a major firewall modification. If you check with V8 Roadsters or Flyin Miata they have all the information you will need in this area of fitment.

LOL. So make something more nose heavy and overpowered than a standard LS conversion, which is already silly fast. It's your money. :-)

The real beauty of the LS swap is it doesn't mess with the weight distribution, so you still have a sweet handling sports car. That's all out the window with the extra weight on the nose of a supercharged motor.

The LT4 will fit anywhere the LS1,2,or 3 fits. The SC cover is actually a bit lower than the top of the stock intake on an LS2. The in-tank Delphi fuel pump for any corvette, 2008 and up, will work just fine. The bell housing will give you fits, though, as the flywheel on this motor is very different than the LS series. If you can mod the front of the tunnel for the T56 six speed, fitting the clutch and bell housing should not be that much of a problem. Just be sure to keep the pedal position in mind when you do it or you'll either be sitting sideways or find it difficult to get on the brakes without hitting both accelerator and brake.

I have a customer wanting an install in an RX8. No dice. My information found that the LT4 is actually about 3/4 inch taller than the LT1 and also there are some issues on the oil pan side of things that increased the height as well. My local GM Performance outlet told me changing the LT4 oil pan voided the warranty on the wet sump crate engine.

I think your local performance guy is blowing smoke up your southern orifice.The supercharger cover of the LT4 is less than an inch above the valve cover on that engine while the intake on an LS3 is 2.4 inches higher. Deck height on both motors is the same so the difference in manifold height is the total difference. As for the warranty with a pan change, The pan on the LT4, like the LS3 and LS2 is a structural element which adds rigidity to the block. Use the dry sump version and you have no clearance problems on the low end either.

Ironically the GM Performance tent is set up at Daytona International Speedway right now for bike week. They have LS3, LT1 and LT4 engines on display. I'll have to head over with a tape measure!

Great Idea!:yippee:

Ok, just got back from the track. Seems my GM guy was really close. LS3 and LT1 are virtually identical from the sump (front shallow portion) to the highest point on the intake at 21". The LT4 comes in at 22". The valve covers and coils are configured totally different so they don't make a good reference point to go off of in comparison to the intake. On an LS3 RX8 swap I have about 1/2" hood clearance so I need to find a way to get an LT4 down a bit but that would mean moving the rack, not ideal. Or a hood bubble.

Dropping the rack leads to really screwy handling. That's why I shit-canned the Boss Frog front crossmember and went with the V8 Roadster subframe. You can squeeze about 0.25 inches by building new motorplates drilled with the motor mount holes up 1/4 in but that's about all you can get. So now all you need to do :eek4: is find another 1/4 inch somewhere. Good luck!

This site:

https://www.improvedracing.com/tech/...dimensions.php

shows the LS3 pan at 1.93" at the shallow point above the rack. It also shows the F-body pan at 1.38" Seems to me you could cut the LS3/LT4 pan down to the F-body dimension and get your needed 1/2" or so.

Mike

My GM source also told me that changing the oil pan can cause warranty issues. If you have an oil related problem and have anything other then the pan it came with, no dice on warranty.

Everybody is an expert right up to the moment when you have to install it, but mine actually fits!

https://cimg4.ibsrv.net/gimg/www.v8m...e5ea0541e6.jpg

https://cimg7.ibsrv.net/gimg/www.v8m...a5e5274da.jpeg
Lt1 here fits fine

Am told it will fit. Lack of available kits/parts is the issue. I may donate my NC just for that.650 hp/tq would be a blast.

Not sure you realize that the OP for this thread has not been on the forum since 02-20-2017 11:33 AM You might want to check such things before dredging up a 5 year old thread in the future.


Bill S.

Will do, thank you Bill.