# Gm engine weights

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#### spaschke

##### Well-Known Member
Thanks ekimneirbo. That sounds like a good way to build one.
I have a 98 vette engine on my Adventurer 333 project right now. Almost ready for final assembly. iron block, aluminum intake, not sure about the heads. About 333 hp and has a belt psru. This is what the plans called for. I am considering an LS engine to lighten it up. I should have all the hp I need with the present engine, so I am not looking for more. But If I could get an engine at least 100 lbs lighter AND then lose the psru, that would be super. But the psru is not real heavy, so I guess keeping it isn't bad. I would rather have fuel injection also.
I think a cam designed for the needed rpm range would help a lot.

#### ekimneirbo

##### Banned
Thanks ekimneirbo. That sounds like a good way to build one.
I have a 98 vette engine on my Adventurer 333 project right now. Almost ready for final assembly. iron block, aluminum intake, not sure about the heads. About 333 hp and has a belt psru. This is what the plans called for. I am considering an LS engine to lighten it up. I should have all the hp I need with the present engine, so I am not looking for more. But If I could get an engine at least 100 lbs lighter AND then lose the psru, that would be super. But the psru is not real heavy, so I guess keeping it isn't bad. I would rather have fuel injection also.
I think a cam designed for the needed rpm range would help a lot.

If you decide to pursue the use of an LS engine, you might watch Craigs List and Ebay for someone parting out a 6.0 liter LQ4 or LQ9 engine....or just selling some heads and maybe the used camshaft outright. The reason I say this is because they have excellent ports (like LS6 engines) but have larger combustion chambers. The 241 casting for the LS1 has a 67.3 cc combustion chamber, while the LQ4/LQ9 (317 casting) has a 71.06 cc chamber and will help keep compression down in a stroker engine. Used LS1 blocks can be found cheaply, but they are very limited on oversize. I have read anywhere from .010 max to .030 max. Less than
perfect placement of the liners in the block can cause thin cylinder walls.....so I would recommend using a new block. As far as camshaft selection goes,the
consensus seems to be that cylinder filling is what to strive for at lower rpms. I think that while a new $300 aftermarket cam might? help, a$25 stock truck cam may do quite well. I would think the completed engine would be dyno tested to see where the power curve is with a stock cam before investing in a
aftermarket one. Here are a couple of attachments which will give you some food for thought. Like everything, this is an opinion, but it was written by a
very knowledgeable person.

One more thing, the truck intakes are kinda ugly but
can be dressed up a little with removal of the unneeded stuff. I haven't looked lately, but I found almost new/low mileage truck manifolds with the fuel rails and injectors but no throttle body for about \$150. If you watch ebay and check regularly you can find real deals on these components. You can't even buy injectors for what I gave for the whole shebang. If someone sits down and takes the time to decide what components they want and scans ebay for a time, they can come up with most of the needed components extremely cheaply.....because the parts you need are the discards that high performance engine builders don't want and there isn't much market for them....sooo they are cheap to buy.

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#### Toobuilder

##### Well-Known Member
Log Member
...I have a 98 vette engine on my Adventurer 333 project right now. Almost ready for final assembly. iron block, aluminum intake, not sure about the heads...
If you have 98 vette engine, then you have an all aluminum LS-1, which showed up in the Corvette in 97.

#### spaschke

##### Well-Known Member
I'll check again. Just bought the project earlier this year. recommended engine was a Chevrolet HO350. Previous owner got the vette engine and had it rebuilt.
Thanks for the great info.

#### ekimneirbo

##### Banned
GM used the smallblock Chevy from 1955 until about 1991/92 then also continued its use in some trucks for a while. In 92/93 they changed to a reverse coolant flow which sent
the coolant through the heads first and then on down to the block. This was a nice engine and it was produced in a couple of different displacements. It was used in several GM
cars (buicks etc). The best version will come from the Corvette/Camaro, displaced 5.7 liters (350 cu in) and was called the LT1. It had aluminum heads,and a cast iron block.
The intake manifold on it was for fuel injection, sat very low, and was made of aluminum. This was still a smallblock Chevy engine for all intents and purposes.

In 97/98 GM produced the aluminum block and aluminum head LS1 for the first time. The intake manifold on it will be plastic.

As time moved on, GM started producing different displacements for use in SUVs and trucks.........these often used various combinations of cast iron blocks,
aluminum blocks,cast iron heads,and aluminum heads. If you have an LS engine, the back of the block should have a number like 5.7 or 5.0 cast into it.
Also, the heads will have a 3 digit number cast into them up by the end of the valve cover. That will tell you a lot about what you have.

If the engine has a carburetor, then it is probably a version of the original smallblock chevy, although carburetors can be mounted on LS engines by using
a different intake manifold and something to power the ignition. If you are unsure what you have, download a couple of pictures of the engine and I'll try

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#### Bin31

##### Member
In the other situation you may wish to remain as light as possible by using direct
drive at 2700-3200 rpms. At the 2700-3200 rpm range you can build engines that will easily produce 200-250 hp.
Do you consider inverting the engine in the direct drive option ?

#### ekimneirbo

##### Banned
Do you consider inverting the engine in the direct drive option ?
Yes, I would probably invert a V8 if I installed it in a high wing airplane.
The reason is to raise the thrust line closer to the wings and lessen the pendulum effect when power is applied or reduced. If installing a V8 in a low wing aircraft, I would
mount it conventionally as the thrust line is near the wing that way.

If you choose to invert an engine, I would look at some of the modifications made by Steve Wittman on his Olds V8. Several things were done to insure oil reached components
like the timing chain. The heavy LS oil pan could be removed and replaced with a light weight plate or pan that has a lower profile. GM uses a stamped metal pan on LS short
blocks that might work if you can find one. This means you would have to locate an oil reservoir somewhere else. One thing to consider is some kind of clip, bracket, or
rev kit that would prevent a lifter from falling out of its hole. If one fell out, you would lose most if not all of your oil pressure.

There are several benefits to inverting an engine. For one thing, the heads are the low point in the cooling system,so there should be no air pockets trapped in them that
would cause the exhaust valve to run hot, and you can probably get away with reasonably high compression ratios. With the LS engine you have no "distributor" per se,
so you don't have to worry about oil leakage or saturated points. It might be preferrable to use the early 97-98 heads that have perimeter bolts on the valve covers,
although I think the center bolt heads probably would be fine.

#### TXFlyGuy

##### Well-Known Member
My choice is an stock crate LS3 engine with an appropriately modified ECU. Nothing crazy or out of the ordinary. Some minor changes here and there, Viola! Marry that engine with an AutoPSRU and go flying. That is what will happen with my P51.
I just ordered the LS3 crate engine. It will be installed in our T-51D Mustang. The Titan factory is already flying an LC9 5.3 Litre 327. I have flown this engine...unbelievable power!

The PSRU is a 1.9 to 1 ratio. Max T/O rpm will be 4,500. The prop will turn 2,370 rpm. The engine will make 350 hp at this speed.

#### BoeveP51

##### Well-Known Member
Are you going to use the PSRU from Titan ?

#### TXFlyGuy

##### Well-Known Member
Are you going to use the PSRU from Titan ?
The gearbox is an Autoflight / Titan PSRU. From New Zealand.

#### Goatherder

##### Member
I built an aluminum 4.3 V6. As pictured engine (with a gawd-awful heavy road-race oil pan) weighs 275lbs. With 1.53 gearbox weighs 350. Hp should be around 300. I think I can make an aluminum pan and knock a few pounds off. Here's a picture of it mounted on a test stand. Turns a 66x74 Catto pusher prop about 2500 rpm. Will power a jumbo-sized Long-EZ

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#### rv6ejguy

##### Well-Known Member
I built an aluminum 4.3 V6. As picture engine (with a gawd-awful heavy road-race oil pan) weighs 275lbs. With 1.53 gearbox weighs 350. Hp should be around 300. I think I can make an aluminum pan and knock a few pounds off. Here's a picture of it mounted on a test stand. Turns a 66x74 Catto pusher prop about 2500 rpm. Will power a jumbo-sized Long-EZ

View attachment 42911
What gearbox is that?

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#### stol

##### Well-Known Member
I built an aluminum 4.3 V6. As pictured engine (with a gawd-awful heavy road-race oil pan) weighs 275lbs. With 1.53 gearbox weighs 350. Hp should be around 300. I think I can make an aluminum pan and knock a few pounds off. Here's a picture of it mounted on a test stand. Turns a 66x74 Catto pusher prop about 2500 rpm. Will power a jumbo-sized Long-EZ

View attachment 42911

I am impressed....

#### Goatherder

##### Member
Also, if you go on YouTube and search for "Marc's v-6 4", posted by mfryer100...you can see us blowin' leaves. Plug in your speakers...the sound is good.