Can theese blocks be used on the street for a daily driver???

They make a ton of power NA, and I was wondering if it was worth it and if the accessories attached to each other, so as the LT1/4 heads?

I would just like to know...

There are 3 types...
The 350 type main bearings
the 400 type main bearings
and the 350 type main bearings with wet sump...

I know this might not be cost effective as you can make all that power with less hassle and money, but for 750 fwhp, you might spend 10-15k on either setup, either the bowtie block or the lt1/4 with a supercharger...

Aluminum blocks don't make power because they are aluminum.
The reason for using aluminum is lighter weight.

For maximum power probably the iron Bowtie (184 casting) blocks are stronger than the aluminum ones.


Of course you can use aluminum blocks on the street. Camaro and Corvette 5.7L LS-1s are aluminum block. Reportedly the 5.3L SSR engine will also have alum. block.

Bowtie blocks are not specifically for LT1, rather for earlier SBC.
It might be easier trying not to convert a Bowtie to an LT1. You'll need better heads than LT1/4 (even ported) for 750 hp NA.

If you want 750 streetable hp on an NA SBC that lives, 10K won't do it, and 15k is shaky. If that's your goal (or budget), go with the blower or nitrous and build a strong iron block bottom end.

My $.02

If you have to ask, they are too expensive! They are about $5,000. If you have the money, of course you could use one on the street. I know of no one who is doing this however. They save ~100lbs compared to an iron block, so it is far from cost effective.

As has been stated, they do not inherently make more power than an iron block. In fact, they are likely to make less, all other things being equal. Aluminum is a better conductor of heat than iron. By taking more heat from the combustion gasses, power may be reduced.

Rich Krause

If you come to think of it...

Then why did they move to an Al block on the LS1?

I just thought that you would be able to reuse your rotating assembly and maybe heads and have the Al block in with a normal cooling flow.. Instead of doing a reverse cooling. And hoping that the rest of the parts are exchangeable too...


If not its easier to swap in an LS1 into the lt1 fbod and it be cheaper.. sin for 2500-3000 you get everything, tranny included... Granted the LS1/6 is a better block than the lt1/4/5.

Just wondering... But if you could reuse your rotating assembly and all that stuff it would cost just about the same as swapping a complete engine, ecm, etc etc etc...

The other thing... If heat is a lot better for the gasses, why is it that lt1 make 20hp less at 200F ECT than 180-185F?

I thought of it in terms of weight, which would improve the distribution and heat dissipation, making it possible to run more HP and easier to dissipate all that heat.

Heat kept in the chamber is good unless it pre ignites the fuel. The rest of the motor i.e. intake, cylinder block, valvetrain, etc.can function more efficiently at a temp that keeps intake charge cooler and oil temp moderate. Aluminum is much more versatile than iron. It's just a bit more expensive to produce. The heat dissipation is easily overcome by a slight increase in static compression.

What do you mean by this?

Thanks

All thing being equal, the iron head will produce more power than the aluminum. That is because it dams more haet in the chambers. Heat =power... sort of. The aluminum headed motor will allow increased c/r with the same fuel and/or more spark advance without detonation due to it's heat dissipating characteristics. More heat more power. (gas expansion actually makes power but you can't have that without heat so they go hand in hand

A mass-produced aluminum block is going to be a much cheaper item than a limited production Bowtie block. I'm sure wieght savings was a huge consideration.... remember... the primary user of the LS1 is the Corvette, where they strive to maintain 50/50 F/R weight distribution. They build essentially the same family of "LS1"-design engines for the trucks, and they are all cast iron "LS1" blocks (the SSR is supposed to use an aluminum block 5.3L engine, again I would suspect that weight is the primary concern).

What parts are you going to reuse? If you are looking for big power out of an aluminum Bowtie block, you aren't going to be taking the cast crank, PM rods and hyperpeutectic pistons out of your LT1 and translplanting them. And you don't even have a compatible distributor. And you can weld and drill the heads to match the "conventional" cooling of the Gen 1 SBC, but why? You would have a large choice of inherently better heads/intakes to choose from in the Gen 1 SBC family.


Again, what are you trying to accomplish. Swap in a fairly stock LS1 engine, and you have a small HP improvement over the LT1.... again, not a cost effective solution when you figure the need to change the K-member, address engine height issues, address the mismatch on the bellhousing, etc. If all you want is 50 extra HP, there are much more cost effective ways of doing it then putting an LS1 in a 93-97.

By the way, you can't include the "LT5" in the LT1/4/5 family of engines... the LT5 is totally unrelated to any SBC designs, and is probably equal to, if not superior to the LS1, and it is an aluminum block engine.... but it wasn't cost effective, adding about $15K to the price of the Corvette.


I still don't understand what you are trying to accomplish..... take a high $$$ aluminum block, and then put a mundane rotating assembly in it.... why?

An engine is a "heat" machine..... it converts energy in the combustion chamber into power at the crankshaft. Reducing the combustion chamber temperature reduces the overall thermal efficiency of the engine, and means it recovers less enregy to apply to the piston/crankshaft, and pees more energy into the coolant where it is lost... basic thermodynamics. However, the energy losses can be offset with more timing, more compression, and any reduction in inlet air charge temperature. In the reverse-cooled, aluminum head LT1/4 design, you can make more gains than you lose, but the laws of thermodynamics still apply. Look up "Evans Coolant"......


If you really feel that way, you don't understand how an internal combustion engine works. Heat is transformed to mechanical energy. Lost heat is lost energy. What do you mean "in terms of weight"....? Are you suggesting that somehow a change in block weight is going to make more power..... please explain... I'm confused. But then I don't understand the whole point of your question, or what you are trying to accomplish.

Originally posted by Injuneer:

I'm confused. But then I don't understand the whole point of your question, or what you are trying to accomplish.

Amen. That's at least two of us.

Good post.

Sorry I put a comma where a period was needed...

There is a weight reduction that is very important... It will even the distribution out...

But, the heat dissipation is a major concern...

I would be reusing what I have right now that is my all forged 383 and afr heads, so I dont think it wouldn't be such a bad idea.

But then again...

The purpose of this was general knowledge as I know it would be a costly project, but then again, which project isn't costly.

The LT5 engine is part of the LT family although, yes, a completely different engine. But I do think the LS1/6 is a better engine than the LT5.

The point of the Al block was the ability to dissipate more heat and to get more power out of a setup. Probably for those people on the 1k HP area... I was just wondering why people didn't use them on the street as they "seem" feasable for what you can do with them... And when 1khp is around the corner, for those people money is not that much of a concern as others.

buy a dart block and make a 440 inch small block. you can make a 470 ci small block but not too streetable. and run bridix 18 degree heads and a huge roller cam and a little bit of juice and you'll have your 700 + hp on the street. i wouldn't run too much comp though so its streetable but you could run as much as you want and make tons of power.

I'm not sure what you mean by "LT family".... it's like saying because the RPO designation for the original LT-1 engine (1970-72) has the letters "LT" in it, it is the same as the current "LT1" engines.... How can a limited production engine, designed by Lotus and built by Mercury Marine be in any way shape or form related to the "LT family"?

How many angels can dance on the head of a pin? .

Not design wise.. Why you guys take everything to an extreeme... If it were not part of what they wanted to be known as why didn't they name the engine the LR1 or something... Or the current LS1 be called LT9 then??? Anyways... The real point on putting LT1/4/5 is because those where the engines available at that time. The LT5 got out at the same time as the LT1 was still in production... so its the same family by desgnation not by desing... Dont get everything to such an extreeme...

The real point to this thread is why haven't more people with big HP numbers used the bow tie AL blocks? With the answer I was expecting technicall stuff that would relate on why or why not.. So I dont see the point in trying to bash tiny detail that are not part of the thread or the question like if LT1 and LT5 are or not the same generation or same type of engine.

The other thing is I have the same last name as my father, yet I am a different person and I am not a copy of him and yet I am still his family... Its a way of seeing or puting things... Please read when I quote, "Although, yes, a completely different engine." The purpose that was to stop this kind of comments that I might have gotten, which I got, that I didn't want, since I do know where they come from and what they are and are not.

Yet the LT5 was available first

Summary: here's why not

1) They are friggen (non-technical expression) expensive for the 90 or so pounds saved, which gives about 2.5% less front weight and 2.5% more rear.
2) They aren't quite as strong as the iron Bowties with the same features like splayed 8620 main caps.
3) There is no power advantage; perhaps a slight disadvantage.