LT5 bare block

[tpepmeie]

Maybe the last LT5 "virgin" block in the world. Who wants a 700bhp / 380 cu. in. engine?

In all seriousness, I am using this block to develop the liners and block machining program for new liners. I'd like to offer aluminum nikasil coated liners up to 4.000, and ductile iron closed deck out to 4.130 bore. The designs are being worked up.

[Blue Flame Restorations]

Neat stuff, Todd

[Paul Workman]

I'm interested! Do keep us in the loop!

Paul.

AES has done a few closed deck LT5s; Bob Gillig's 427, Al Dashto and Kevin Costello's 441s (cranks came from Bryant, IIRC). I don't know if that would interest you - save having to do some of that machining - or NOT (I dunno). But, the 4.000 nikasil liners are VERY interesting, especially if the machining to the block was minimal.

My pending build plan would be a sleeve and cam re-grind - NO offset grind on the crank seriously being considered at the moment. Being able to have 4" nikasil aluminum sleeves...would be ideal for what I would hope to be a very reliable upgrade.

[A26B]

Great concept Todd.

Rebuilding the LT5 with new rings & sleeves is becoming a vanishing possibility. The first item to go extinct will be rings, then sleeves & new pistons.

For several years now, I have been toying with the idea of developing a major overhaul kit comprised of new sleeves, pistons & rings, with an increase in bore to 4.00". I see no reason to rebuild with a stock 3.90: bore. I am glad you are doing this and I would be glad to refer my customers to you for those parts or buy from you for my customers.

[tpepmeie]

Jerry,
the problem with an aluminum liner is getting enough wall thickness at the bottom. You cannot go less than .120, or the liner won't have the necessary stiffness, at least I wouldn't feel comfortable less than that. I have a Cosworth XD wet liner which is .120". Stock LT5 is about .135".

An iron liner can go .080" or even less because of the stiffness of the material.

If I go ahead with the Aluminum liners, the OD would be oversize and thus require the bottom of the block to be machined larger. This shouldn't be a big deal for most competent machine shops. Nonetheless, a 4.000 aluminum liner wouldn't be a "drop-in" replacement.

So, why bother? Well, a couple of reasons, mainly the same that Lotus decided. 1) lighter weight-not a big deal for most of us, 2) better wear resistance, and 3) friction reduction again due to the properties of the coating.

[tpepmeie]

Cosworth liners and the OEM LT5 liners. Guess which is which

[W i l l]

Hi Todd, I think there is a speck of dirt on the floor.... Just kidding. Nice shop!!

[W i l l]

Since aluminum 4.00" liners would not have enough wall thickness, would it be possible to machine the liners from titanium (for strength) and line them with Nikasil (for wear resistance) to avoid machining the block? Not that I have anything against deflowering virgins..., but just looking for an alternative to block shock

[tpepmeie]

Will, I don't think Ti would be a very good liner material, and I am not aware of anybody who uses it. From what I understand, the surface properties aren't well suited to any application which involves rubbing or friction.

I'd still like to concentrate on the Aluminum liners, but I'm not sure there is much of a market there. The cost would be more than twice what the LA sleeve iron liners are because of the nikasil coating, plus the additional block machining. For a 4.00 bore at nearly any moderate performance level it's hard to beat the economics of the good old ductile iron sleeve. LA Sleeve sells these for $145 ea. retail and they drop right in.

Hopefully I can have something new to display at BG this year. Whether it will be iron or Al, I'm not sure yet.

[Paul Workman]

Looking forward to seeing you and your creation!