Question: Crate engine advice

[coffeejolts]

I am beginning my research on a crate engine for my L81. It seems like everyone + dog builds small block Chevrolet motors. There is just so much information to parse through, and I don't know enough about the topic to know what I don't know. I'm looking for some advice.

I have a bone stock L81 with 42k miles on the odometer. I love the car, but the engine just does not have enough power. I do not want to modify the original motor or transmission. I'd rather replace them and save the original setup in case I ever want to sell the car.

Here are my requirements:

1. Reliable performance: I'm not an engine builder. I want an engine that will be no less reliable than my stock L81.
2. Between 400 and 500 horsepower with tons of torque.
3. Must work with stock gauges and fit under the stock hood.

As of now, I am leaning towards the GM ZZ383. Is this a good choice or am I completely off base? Thanks in advance for any advice you can give me on this.

 

[spikebot 81]

I'm for sure no expert and there are many more qualified here to answer your questions. I think the 383 would be a great choice. In my research I've found the dana 44 rear end is the weak link for HP. The th350c trany is plenty strong. Some guys have some high HP with the stock setup but I feel 400hp at the crank is about as high as I want to go. My 81 has 140k yours is far newer other than 27 yrs old. Put the wood to it and see what breaks

 

[douglasamariani]

I Agree..Anything more than 400hp and that Dana 44 rear may let go on you.

 

[sstearns2]

I Agree..Anything more than 400hp and that Dana 44 rear may let go on you.

It seems to me that a Dana 44 would be fine since street tires will just break loose before you hurt the rear end. It sounds to me like people start breaking things when they go to sticky slicks.

400-500 HP is a lot of power. I have to think that going from a stock L81 to a ZZ383 will be an acceptably huge increase in performance. I'd go with a built 4 speed auto for sure.

Good luck,
Scott

 

[Rodney Gold]

400-500 hp from a sbc , even stroked to 383 will not be a streetable car - you would have to use a high , circa 3000 rpm stall to utilise the powerband and will have many other issues beside.

If you really wanted to go that route , I would rather use some aftermarket sbc block and go 427 or 454 with it , that way you can keep the powerband in a useable range , have the gobs of torque you feel you need and still keep everything the same in the engine compartment and have an engine that doesnt rev in the stratosphere and will live real reliably.
I would also follow the advice of scott ... I just think that the power you will get from the direct swap will be more than enough for you..and going for an OD box would enable you to use a low rear gear for street fighting . like a 3.55 and still rev nicely at highway speeds.

 

[KANE]

I am beginning my research on a crate engine for my L81. It seems like everyone + dog builds small block Chevrolet motors. There is just so much information to parse through, and I don't know enough about the topic to know what I don't know. I'm looking for some advice.

I have a bone stock L81 with 42k miles on the odometer. I love the car, but the engine just does not have enough power. I do not want to modify the original motor or transmission. I'd rather replace them and save the original setup in case I ever want to sell the car.

Here are my requirements:

1. Reliable performance: I'm not an engine builder. I want an engine that will be no less reliable than my stock L81.
2. Between 400 and 500 horsepower with tons of torque.
3. Must work with stock gauges and fit under the stock hood.

As of now, I am leaning towards the GM ZZ383. Is this a good choice or am I completely off base? Thanks in advance for any advice you can give me on this.

Sounds like you want more pep. I get the feeling you won't be drag racing on a sanctioned strip or between stop lights either.

I think 300hp (target) to 400hp (max) will be plenty. You said you want to preserve the factory engine and tranny- so that tells me you want to keep it stock outside of the big pieces.

Rodney makes a great point- a 500hp C3 in all-but-the-engine-&-tranny stock Vette won't be streetable. The factory never set it up for that much power. Besides, you'll outspend the fun factor as you re-engineer all the drivetrain components to keep up with a monster block.

My thoughts: Go with a ZZ4 and a 700R4 transmission. The ZZ4 has plenty of grunt and the OD tranny has a great first gear. Between those two, you'll see a completely different car emerge from the shop. Evolution80 has that combo and he really likes it.

 

[Hib Halverson]

The GMPP "ZZ383" engine is a 383-cuin "long-block" that, given a proper intake manifold and carb choice will produce about 425 horsepower and 450 lbs ft torque and....that performance comes from an engine that is certainly streetable in the sense that most performance enthuaists have of the word 'streetable". Additionally, the ZZ383 has aluminum cylinder heads and that takes 30-40 lbs off the front end...a good thing.

The only problem with getting that engine's projected performance is the intake and car choice and the right one will probably require fitting the car with a different hood. There are choices that may fit under the stock hood, but they'll all be performance compromises (through manifold design and restricted air cleaner assemblies) compared to an Edelbrock Performer RPM, a modified Quadrajet or a 700-750 Holley and a high-flowing air filter assy.

The D44 axle is marginal in that application, but provided the rear tire package is not to large and sticky, if it's in excellent condition with a properly operating limited slip and uses the right lubricant, you'll be ok.

The transmission choice is going to be critical. Neither stock trans for that model year are going to be very durable.

 

[ChrisR8C]

I have just installed a 383 of this hp range in my "80". I used the Professional products intake ( compared to the Edl RPM ) and holley 750. It does fit under the hood with a drop base air cleaner and 3" filter with about 1/2 in. of clearance.

I am using a 700R4 with 3:73 gears and a 2400 stall converter. The tires I have are 265-50-15 BFG and a quick blip of the throttle will start them spinning.

 

[KANE]

I have just installed a 383 of this hp range in my "80". I used the Professional products intake ( compared to the Edl RPM ) and holley 750. It does fit under the hood with a drop base air cleaner and 3" filter with about 1/2 in. of clearance.

I am using a 700R4 with 3:73 gears and a 2400 stall converter. The tires I have are 265-50-15 BFG and a quick blip of the throttle will start them spinning.

AWESOME! Someone who has done it!

Tell us more Chris!

 

[coffeejolts]

Yes, I would definitely like to see pictures of how you fit it all under the stock hood.

 

[ChrisR8C]

Yes, I would definitely like to see pictures of how you fit it all under the stock hood.

I'll get some new pictures and post them in the next couple of days. Let me see if I have any of it going in.

 

[ChrisR8C]

This is the 383 on the stand, and 2 of it going in.

 

[ChrisR8C]

2 more. The new Alum radiator and fans. The front with cleaned up pulleys.

 

[ChrisR8C]

More pics, all under the stock hood.

 

[coffeejolts]

Very nice. How big is the drop on that air cleaner? Also, what is the advantage of the 383 over doing a LS3 swap? Crate engine depot has the zz383 listed at $5,228 and the LS3 for $6,134. After purchasing the intake and carb for the 383, I'm looking at the same amount of money. Perhaps I'll end up spending $1,500 more for the LS3 after all the adapters and the wiring harness, but it seems like it would be worth the money.

What are your thoughts on zz383 vs LS3?

 

[bucket]

More pics, all under the stock hood.

........

very nice..now you can pop the hood and with your best poker-face say..."It's Stock"....lol

 

[Koop]

GM ZZ383 installed in my '69. Works nice with the GM aluminum intake, I think the owners book says I make 10 less horsepower using this manifold than the 425HP it's rated at, a small sacrifice to keep the original hood. At a glance, the only obvious not GM items are the Thorley headers. I've never gotten around to putting the chrome ignition housing back on, it requires some minor mods to put it back.

Big Block power, small block weight (399 pounds delivered I think?) with Aluminum intake, pistons and heads. It was as close to a direct swap as I could get. It makes plenty of vacuum to run everything, it's smooth and great for daily driving. Maybe a little to smooth, (I wanted more cam!) but I wanted reliable. TH400 trans with a 2,100 stall converter and a very slight shift kit, the original (never been repaired) 3.08 rear end with a Gazillion miles on it. Deep groove pullies, electronic ignition, rejetted stock quadrajet.

It is fun to say it's a stock small block chevy with some headers.

But a new Z06 can still kick my ass.

I don't know what it'll take to get this under the hood of a newer car, but I like it.

 

[baxsom]

Very nice. How big is the drop on that air cleaner? Also, what is the advantage of the 383 over doing a LS3 swap? Crate engine depot has the zz383 listed at $5,228 and the LS3 for $6,134. After purchasing the intake and carb for the 383, I'm looking at the same amount of money. Perhaps I'll end up spending $1,500 more for the LS3 after all the adapters and the wiring harness, but it seems like it would be worth the money.

What are your thoughts on zz383 vs LS3?

well the 383 will drop right in,
the LS3 will need the computer, pulley system, o2 sensor in the exhaust and electric fuel system installed.

 

[Koop]

Very nice. How big is the drop on that air cleaner? Also, what is the advantage of the 383 over doing a LS3 swap? Crate engine depot has the zz383 listed at $5,228 and the LS3 for $6,134. After purchasing the intake and carb for the 383, I'm looking at the same amount of money. Perhaps I'll end up spending $1,500 more for the LS3 after all the adapters and the wiring harness, but it seems like it would be worth the money.

What are your thoughts on zz383 vs LS3?

I think the LS3 is going to run you plenty more than $1,500 extra, it's not a drop it in a go situation. I was first looking at putting in an LS2 and it didn't seem worth the effort or $. The ZZ383 or the ZZ4 is quick, clean and easy.

I don't know what carb is on your car, but my stock carb feeds plenty of fuel and works great on the ZZ383. I use a stock radiator as well, I just didn't see any reason to put up the extra $ for an aluminum radiator. I do run my car to the desert a few times a year in 100+ degrees and heat is not an issue.

In reality, the ZZ4 is probably a much better buy than the ZZ383, that's a very nice motor and really should be considered.

I wanted to do the 700R4 and 3.73 rear, but my mechanic talked me out of it. His opinion was the TH400 and the 3.08 is the right match for street use and my driving habits. He's done a number of the ZZ383 conversions with the 700R4, sticks, different rear ends and tons of custom motors. So I do listen when he talks me out of spending my money.

I will say that as time has gone on I really prefer the LS6 in my Cadillac to the ZZ383 in the Vette, that LS6 is one smooth motor and I'd bet the LS3 is even better.

 

[coffeejolts]

I think the LS3 is going to run you plenty more than $1,500 extra, it's not a drop it in a go situation. I was first looking at putting in an LS2 and it didn't seem worth the effort or $. The ZZ383 or the ZZ4 is quick, clean and easy.

I don't know what carb is on your car, but my stock carb feeds plenty of fuel and works great on the ZZ383. I use a stock radiator as well, I just didn't see any reason to put up the extra $ for an aluminum radiator. I do run my car to the desert a few times a year in 100+ degrees and heat is not an issue.

In reality, the ZZ4 is probably a much better buy than the ZZ383, that's a very nice motor and really should be considered.

I wanted to do the 700R4 and 3.73 rear, but my mechanic talked me out of it. His opinion was the TH400 and the 3.08 is the right match for street use and my driving habits. He's done a number of the ZZ383 conversions with the 700R4, sticks, different rear ends and tons of custom motors. So I do listen when he talks me out of spending my money.

I will say that as time has gone on I really prefer the LS6 in my Cadillac to the ZZ383 in the Vette, that LS6 is one smooth motor and I'd bet the LS3 is even better.

You're probably right about it being more than $1500 more for the LS3 than the ZZ383. I hadn't considered reusing the pulleys from my 350 on the 383. My stock computer controlled carb probably would not work, but maybe it would. Dollar per horsepower, the ZZ4 is hands-down the best option. I could probably get it all in for under $10k including upgrading the transmission and diff. That is far under my 16k guesstimate for the LS3 and all the goodies.

I hate being rational. Someone talk me back into the LS3 before I change my mind for good.