Thread: 377 Build

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Howdy Folks,

I am getting excited over here. There's light at the end of the tunnel for my kit car build. The engine for it is a dry sump, high-rev (8k) 377ci aluminum SBC (Brodix?) to make between 600-700 bhp and 450-550 Ft TQ.

Here's the exact engine...I just don't have the $20k for it: http://www.amerspeed.com/ultima.htm

So, I am going to build it myself...with a little help from friends and this list perhaps. The kit car I am building is the one mid-page.

Question 1: I know there is desktop dyno software out there that creates "virtual engines" to estimate performance. Does anyone have experience using these packages?

Question 2: I have been told by different folks that a 377ci is made two ways; a 400 block with a 350 crank, and a bored 350. Are there really two ways to make a 377, or is one method more accepted than another?

Thanks all. I am sure this is just the start of a long string of dumb questions!!!

Originally posted by techinspector1
Be honest Scott, do you have the money to do this or are you just bench racing. I'm asking because apparently you don't even know how to start building a 377, much less how to pick the right parts to keep it together at 8,000 rpm's, so you're gonna have to rely on a professional engine builder. The alloy block will be somewhere in the neighborhood of $6,000, so this motor assembled by a pro will be at least $26,000 and you haven't even started on the remainder of the drivetrain or the car itself.

Okay, that's what I thought...400 bored with a 350 crank. I asked because I know someone with a 377 in an Ultima. They beileve it's a bored 350 and are probably mistaken. Everything I have found on the Net says 400 with 350 crank.

To answer your question about money...money I got. Knowledge I want. Money to waste is another question. Not wasting money is how I got the money I have. You know. It's called saving your pennies. Duhhhh. I could buy the car completely built by the kit maker, if I wanted. The goal here is to learn and build something with my own two hands. I didn't come to this list for financial advice. I was looking for information about engines.

And apparently, you didn't comprehend my post very well. You suggest that I "don't even know how to start building a 377, much less how to pick the right parts to keep it together at 8,000 rpm's, so (I will) have to rely on a professional engine builder." What, really, is the intent or benefit in this bit of "info"? Not to be rude, but I will bet you there are many, many things that I can do that you might find quite impossible. And, learning how to build an engine is one of them.

Did you even notice that I put the right combination up there? FYI, I have a strong idea as to the other parts as well...Jesel, Brodix, Chapman, C&A... But, that's what I came to the list for. Aren't there engine builders on this list that share their knowledge? Seriously, my finances are really none of your business. You should be more concerned about the value of the content in the posts...especially your own post.

Time for you to be honest. Have you ever built an engine from the block up. If not, although I appreciate your links to information on the web and your cut-and-paste above, your really not going to contribute much. If so, why not share that knowledge?

Thanks!

That's what I thought. You too!

What exactly are you doing with this combination ? If you are using it for street use concentrate more on low end torque, than high end horsepower, you will have more fun and less expense that way.

Just wondering what's that Porsche Transaxel rated at for torque?

Hey, hey, hey Scot, I know what you mean in that you want to tie your own shoes. Most of the fun is designing your dream engine and designing it yourself, but the down side is that it is easy to make a mistake or two that will cause severe problems on startup after a substantial investment. I would say Tech1 is a little on the conservative side BUT he really knows his stuff as you would realize if you had looked at his past (very helpful) responses. Since you are nearer the west coast, shipping from PAW is much less for you than for folks on the east coast so I suggest you take a look at the many optional engine builds in the PAW catalog and order up one you like and then have the fun of the experience of the fun and tension of knowing that how you assemble the engine might be just right or might just destroy the engine the first time you start it up. Were it not for the shipping I would have preferred the PAW 383 which comes already with the clearance taken care of for the stroker crank. I get it, you could afford a top of the line crate motor (see the add at the top of the Forum page) but you want to say you built it yourself. I think the best compromise would be to get a PAW kit motor and accept the responsibility for the assembly yourself. As it is I am biting my nails every step assembling my 350 starting from a locally built short block BECAUSE I have built several other engines and found that small mistakes had an effect on the result. Item 1: a small pinhole leak in an aftermarket intake burned the valves on a VW rebuild. Item 2: using stock lifters with a aftermarket cam led to rapid wear of the lifters in a VW. Item 3: chopping the flywheel on a MG midget led to rapid wear of the clutch since the machinist shaved the face of the flywheel as well as the circumference. I could go on and on with personal mistakes that seemed to be "little" but had negative affects later on, so if you want to assemble the engine yourself, give yourself a break and buy an engine kit from PAW AND take heed of free advice from folks on the Forum who have vast experience if you ask them the right way. Since I am new to the SBC 350 I have learned a lot from this Forum and in fact many things that I didn't know I didn't know. On the other hand you can read every word of the Chilton's manual ten times!

Don Shillady
Retired Scientist/teen rodder

Originally posted by southerner
What exactly are you doing with this combination ? If you are using it for street use concentrate more on low end torque, than high end horsepower, you will have more fun and less expense that way.

The car will be driven around town for the odd thrill, but mostly to the tracks - Thunderhill, Buttonwillow, Laguna Seca... Maybe trailored 50%, but it's street legal. So, I plan on driving it a lot. Not a daily-driver though. I have a modded '96 Impala for that.

Originally posted by Mike P
Just wondering what's that Porsche Transaxel rated at for torque?

Depending on the model, up to about 300 ft. lbs. But, the trans is also modded to handle the torque.

As a side note: This car has been around since about '91. There are only about 100 in the USA, but many hundreds in England and Europe. The car just set the world record for 0-100mph-0 at 10.3 seconds for a registered vehicle on street tires. It holds every track lap record in Europe for street-legal cars. It's a fairly well-proven design.

Originally posted by Don Shillady
Hey, hey, hey Scot, I know what you mean in that you want to tie your own shoes. Most of the fun is designing your dream engine and designing it yourself, but the down side is that it is easy to make a mistake or two that will cause severe problems on startup after a substantial investment. I would say Tech1 is a little on the conservative side BUT he really knows his stuff as you would realize if you had looked at his past (very helpful) responses.

Hi Don,

You are probably right. My response was a little heavy-handed. But, the point is that Tech1 doesn't know anything about me and I don't know anything about him...so, what's with the presumptions? If you equate Internet forums to a school and source of learning, the books don't start by asking about your financial status and state publicly that you don't know everything the book does. Ask me about my $$$ and I figure someone is trying to sell me something. He apparently presumed I was indigent and ignorant. I presumed he was meddlesome and arrogent. Tech1 was right about ignorant. I have a lot of learning to do... Don't we all? That's why we join lists like this. BTW, the completed car (from a kit) is about $80k and I have been planning the build for about 3 month. A rolling chassis from the factory is $90k. So, the savings are great in building it yourself.

Anyway, maybe that's the best program to follow (PAW). I didn't know about them and will look into them further. I have been reading a lot about engine construction, but I know there's no replacement for EXPERIENCE. Sounds like you've had some interesting "fun" with your experience!

I have done a fair amount of "bolt on" type mods...engine and suspension. The deepest I have been into an engine is rocker and spring replacement on LT1 heads (my '96 Impala). Shallow, at best. I consider myself capable, just never motivated to build an engine before. Now, I have a reason. And, I will have some local help from a guy that has been building cars since the mid 70's.

My original post had two (generic, I thought) questions about desktop dyno software and 377 base configuration. I think the 377 question is resolved. Have you ever tried any dyno software?

Thanks, and I appreciate your comments.

Someone stuffed this twin turbo into the same car!!!
http://www.spectrum5racing.com/DCP_0667.JPG

Hi Scot, with an adequate wallet you should find several engines of interest in the PAW calalog. To partially respond to your dyno-software question, I have not bought any yet but I have studied in considerable detail Ryans SBC dyno page:

http://www.ryanscarpage.50megs.com/combos1.html

There are quite a few hardware combinations there. One limitation is that Ryan's list does not show the rpm curves. Comp Cams had a page with full H.P. and torque vs rpm which was very informative but it may have been removed. Edelbrock also has a site with a number of such curves for their products. The list by the Ryan site has a list of references at the end of their page and probably there are curves in the original papers. The comment above about low rpm torque being better for the street is in agreement with my views.

Don Shillady
Retired Scientist/teen rodder

Originally posted by Don Shillady
Hi Scot, with an adequate wallet you should find several engines of interest in the PAW calalog. To partially respond to your dyno-software question, I have not bought any yet but I have studied in considerable detail Ryans SBC dyno page:

http://www.ryanscarpage.50megs.com/combos1.html

The comment above about low rpm torque being better for the street is in agreement with my views.

Thank you for the references, Don. Yes, I have read through the entire site at Ryan's. Excellent reading!?! I particularly like that Ryan has discovered God drives a Chevy...probably a '70 425hp 396 Camaro SS

Also, I ordered the PAW catalog today. It should be here in about 3 weeks (years)!!! I have been reading the websites of Jesel, Brodix (got that catalog today), Chapman, and CompCam, as these are the known parts in the American Speed 377.

Looks like a guy could spend $40 to $300 on this kind of desktop dyno software. Don't think I want to go there without seeing it, or at least speaking with someone that has used it before.

While I do agree that low-end torque is important, the GTR only weighs 2,200 lbs wet. So the low end of low-end torque may not be as important for this rig. My Impala, on the other hand, has more torque than HP. It weighs in at about 4,200 lbs.!

The close-ratio transaxle is designed for about 8k RPM max. The 377 should turn 7,500 without over-stressing the assembly. I don't know what the piston ft. per second rate is for that RPM, but the parts makers will have to support that requirement.

Don - Tech1,
Here are some additional high-HP combinations with forced induction (starting on page 8):
http://www.procharger.com/pdf/Chevy.Prod.du.pdf

Thanks again,

If you are serious about an aluminum block, like a Rodeck or Brodix, they are very similar, Brodix copied Rodecks design, hang around some sprint car guys. They will only repair a block 2 times before it is scrap to them. I picked up a 93' Rodeck Block that had been windowed twice and been repaired buitifully. Once they blew it up again (blew the No. 2 web out) they were going to throw it away. I picked it up for $650. Had to get it fixed, that cost me $1000, but I had to covert it to wet sump. Believe me I'm not rich, took me 5 years to build it. I leaned a lot. If you get a good machinist they will help guide you, mine did. The only problem finding a used block is the deck height and most newer blocks the sprint car guys are running don't have starter or fuel pump provisions anymore, weight you know!

Originally posted by blwn31
If you are serious about an aluminum block, like a Rodeck or Brodix, they are very similar, Brodix copied Rodecks design, hang around some sprint car guys. They will only repair a block 2 times before it is scrap to them.

Hi Blwn31,

That sounds like a good tip. I hear that NASCAR engines are also a good value used. I will check into the sprint car guys, too.

I picked up a 93' Rodeck Block that had been windowed twice and been repaired buitifully. Once they blew it up again (blew the No. 2 web out) they were going to throw it away. I picked it up for $650. Had to get it fixed, that cost me $1000, but I had to covert it to wet sump.

Geezzz! What a deal! By "windowed", do you mean a hole in the block?

Believe me I'm not rich, took me 5 years to build it. I leaned a lot. If you get a good machinist they will help guide you, mine did. The only problem finding a used block is the deck height and most newer blocks the sprint car guys are running don't have starter or fuel pump provisions anymore, weight you know!

Hey, rich is relative. I know plenty of "rich" guys that can't save a penny. They have lots of stuff and live paycheck-to-paycheck. I wouldn't take this on, if I couldn't pay my bills! On the other hand, I am completely addicted and could become a junkie!!! BTW, it's taken me 5 years to remodel my last house.

The GTR is a little picky about the block. The whole car is only 42 inches tall. I was going to use in-tank fuel pumps (two tanks) with an in-line primary, filter, and regulator. The starter can be moved to the trans on some models. Although it may take a little more work to find that kind of block, sweat equity is always a good thing. If there happens to be availability when the block is required for the build, that could be an option. Thanks for the heads-up...

Builder,
You can get a 377 from a 350 block, you just have to use a 400 crank and not bore the block, hence a 377.
I presently have a 377 in my 73 Camaro, it's a high revving version redline at 7800 though have had it to 8200 by accident. It's a good running motor and would do very well in a light car like you intend to build. I don't have all of the good stuff you plan on putting in the one you intend to build. I am running a 4 bolt 400 block, stock forged steel chevy crank and stock rods that were polished and shot peened. Running flat top forged full floating pistons, Victor Jr. Heads and super victor intake, topped by a 750 carb shop double pumper holley. Have a lunati cam 260 intake duration and 266 exhaust duration with .640 lift with 1.6:1 rockers, and lifters, driven by a pete jackson gear drive, the quiet one.
To get the power you want out of the 377 your gonna have to go with a really stout compression ratio or supercharge it. A blower is much more streetable depending on boost. It's a whole lot easier to get the kinda HP your looking for with a big cubic inch motor, such as a crate 572 from chevy, and you could probably be in about the same price range as building the 377 to that kind of HP. The streetable version of the 572 has 620 HP and the race version has 720 but you have to run race fuel as the compression is up there, think it's 13 to one.
I regret not putting a bigblock in my car all of the time.
Another option is one of the stroked up small blocks, I've seen them as high as 455 cubic inches, but that's pushing the limit on the block and all of those other moving parts.

Originally posted by 73RS
Builder,
You can get a 377 from a 350 block, you just have to use a 400 crank and not bore the block, hence a 377.

Hi 73RS,

Okay, now I am confused again. If you read the first reply, Tech said "apparently (I) don't even know how to start building a 377, much less how to pick the right parts to keep it together at 8,000 rpm's..." Just plugging the numbers into my calculator, both methods come out as a 377. Both methods = 400 block with 350 crank, 350 block with 400 crank.

I presently have a 377 in my 73 Camaro, it's a high revving version redline at 7800 though have had it to 8200 by accident. It's a good running motor and would do very well in a light car like you intend to build. I don't have all of the good stuff you plan on putting in the one you intend to build. I am running a 4 bolt 400 block, stock forged steel chevy crank and stock rods that were polished and shot peened. Running flat top forged full floating pistons, Victor Jr. Heads and super victor intake, topped by a 750 carb shop double pumper holley. Have a lunati cam 260 intake duration and 266 exhaust duration with .640 lift with 1.6:1 rockers, and lifters, driven by a pete jackson gear drive, the quiet one.

Nice! So, you are running the 400 at 30 over and 350 crank making the kind of RPM I am looking for. Have you put it on the dyno?

To get the power you want out of the 377 your gonna have to go with a really stout compression ratio or supercharge it. A blower is much more streetable depending on boost. It's a whole lot easier to get the kinda HP your looking for with a big cubic inch motor, such as a crate 572 from chevy, and you could probably be in about the same price range as building the 377 to that kind of HP. The streetable version of the 572 has 620 HP and the race version has 720 but you have to run race fuel as the compression is up there, think it's 13 to one. I regret not putting a bigblock in my car all of the time.

I hear'ya... Unfortunately, a BBC won't fit in the "stock" design. And there isn't much room for a blower. I have seen a twin-turbo setup though. It was crammed and had major cooling issues. Forced induction may be the only way to get the power, though.

Another option is one of the stroked up small blocks, I've seen them as high as 455 cubic inches, but that's pushing the limit on the block and all of those other moving parts.

The faster revving 377 is probably more appropriate for the trans...so I don't have to replace all of the gears. My guess is that the shorter crank of the 400 block and 350 crank will handle the RPM better than the 350 with the 400 crank...less feet/second for the pistons. This is why I am considering the software dyno...to play around with some of these figures. It would be great if I had the experience and could say, "Oh yeah, just put these parts in that block and you've got it." Short of calling the guy at American Speed, I am not sure of another way to get this done. Here's an interesting site with various calculators: http://www.bgsoflex.com/auto.html