What’s the pick of the litter on Straight 8 engines?

Sorry if this response comes off a little bit ramble-y Frenchyd, there's a lot that I know but it hasn't really been "condensed" I guess I would say.

1) Budget? I'm not considering one yet, simply because this is an idea and a project that will be years in the making and working with 70+ year old iron. I would say at best, I'm going to be as frugal as possible and try to plan as best I can so I don't get caught off-guard.

2) How far do I wont to go? I try not to build anything to numbers, I'm really just trying to make the engine as efficient and fun to drive as I can. I plan on making more of a roadster/speedster type build, so even if it was "only" 200HP if it was fun I wouldn't mind at all. Part of the reason I want to make all these modifications is, I just kinda want the mental excersise to see how far I can take this elderly technology with modern stuff.

3) I've rebuilt a handful of things and I've got more than enough people around me to help. But if you're always waiting for the perfect time it'll never come, so i'm compiling information and ideas NOW so when I just start "doing" i'll be ready and have good things to work from that i've been prepared for.

4) Believe me, It'll be original with what I'm scheming Using one of these long bois alone is unique enough, anything I do on top of that will just be gravy.

5) Modification experience is my Achilles heel here because the two "main" engines (I feel like it'll come down to at least, there's been few other opinions so far) are either the first stumbling beginnings for overhead valves OR the end of a technology slowly made as could as it can get over 50 years. I guess what I'm trying to say is, there are VERY Deep relations between bore and stroke that I haven't yet fully understood and some things remain Theory to me, which is made all the more interesting by these engines limitations.

For instance- I know that Packard engine, if I went with it, likely shouldn't go higher than 9-10 :1 compression or thereabouts no matter what HEI or fuel injection I could toss at it because (stop me if I'm wrong) eventually your combustion chamber in the L head becomes so small it becomes some kind of detriment. On top of that is the real reason I want to boost it; it's not just because boost is cool, it's also to force air through a complicated air path and make sure that whatever E36 M3 intake I make doesn't affect performance.

Also, I can use IH pistons in the Buick motor? Hot damn, I'll look into that thanks.

Little known,

         Stutz DV-32.   322 cu.in.  156 hp at 3900 rpm.

In reply to GIRTHQUAKE :

You have that right about high compression and flatheads. As compression goes up flow goes down. Since the valves are on the side basically you mill the top of the block to increase compression and part of the force of the burn is wasted pushing on parts that don't move. ( non piston parts ) so some of that energy is wasted just heating up the motor.  

Overhead valves solve that issue in that all the force pushes on the piston. However the small bore long stroke limits the size of the valves. 

With Buick the fireball head is designed to achieve better fuel mileage not more power.  If you open that up you will get much better flow but lose compression ( since the most you start will is 7.5-1  there is a lot of room for improvement )  

Now if you supercharge the engine that's OK but be careful a 40 inch long engine using a supercharger designed for a shorter V8 and it will look funny. Now a 12-71 might be long enough to look respectable but even well under driven it will put out a lot more boost than 320 cu in can handle not to mention the efficiency will be terrible. 
A centrifugal blower could look period correct  they had those by the late 20's and they all look similar.  The problem will be matching the carb to the demands. Modern EFI would not be an issue but I tremble in fear of attempting to get the carb working on one.  Fuel demand is not linear in any way. It goes from massive at start up to tiny at idle and then starts curving up nearly vertical as you reach peak RPM 

One other thing here, alcohol is a better fuel for this application.  Alcohol has a slower flame front then gasoline so the burn pressure continues further down the stroke.  Plus alcohol is more tolerant of mixture. It will run both leaner and richer than gasoline ( although gasoline will help initial starting )  perfect application for E85  

I have no knowledge to impart. My (very correct and indisputable) opinion is that the only thing cooler than a straight 8 would be a flathead 8. And the GRM even ran an article on flatheads for endurance racing, so don't discount the simpler valve train. Simple is reliable. I would think that the lower compression/boost combo would be the way to go. Especially with a stealthily implemented port injection setup. I would imagine that the cooling system could be tweaked too with some care and maybe electric water pump(s). Anyway, I really like the idea. Eagerly awaiting the well documented build. 
 

*edit for hair brained ideas that just struck me. 
heat. It must be shed. If you were to use a flathead, it may be possible to either cast your own or modify a cast one. If you're looking at machining it flat anyway, why not weld big meaty cooling fins, or water passages? It's a bit of dark magic, but cast iron CAN be welded. Just spitballing. 

In reply to barefootskater :

My Opinion ( worth exactly what it costs ) is a supercharger would be a major hindrance to completion.  Alignment in 4 axis puts extreme demands on fabricating skills. And since most blowers are designed for V8's will look silly on a inline 8. Yes a 12-71 might look a little better but would need to be massively under driven to avoid excess boost. To the point of being way out of the efficiency range of that blower at low RPM. 
Not a good place too be. 
 

Centrifugal blowers would be OK looks wise since they were used from the late 1920's  but carburation  would be horrible.  It needs a massive dose of fuel at start up and idle a tiny trickle.  But the problem with centrifugal blowers is their fuel requirements are anything but a straight line.  Actually it's a very sharp curve. Something carbs really have a problem adjusting too.  
 

Then add the cost of the blower, drive, and carburation  to get everything working. I see delay after delay. 

 The Buick makes up to 170 Hp 290 ft pds of torque. To start.  I can see 300 horsepower with 4 simple SU carbs. A simple tube and two flange manifold per carb.  A camshaft reground, pistons with 9.0-1 compression. And headers. 

You could even hide the SU's with what appears to be a oil bath air filter 

frenchyd said:

Now if you supercharge the engine that's OK but be careful a 40 inch long engine using a supercharger designed for a shorter V8 and it will look funny. Now a 12-71 might be long enough to look respectable but even well under driven it will put out a lot more boost than 320 cu in can handle not to mention the efficiency will be terrible. 
A centrifugal blower could look period correct  they had those by the late 20's and they all look similar.  

This aesthetic problem could be solved by mounting the supercharger hanging off the front of the crank, ie Potvin or blower Bentley style. It would certainly accentuate the already lengthy length of an I8.

In reply to newrider3 :

That's a nice idea. 
 

My favorite straight 8 car is the one in The movie Topper with Cary Grant.  The one with the great big tail fin. 

Curtis73 (Forum Supporter) said:

Two 4BTs welded together?

I'll see myself out.

The thought of two 4bts made my phone shake so bad the screen cracked.

As long as we're tossing out unusual and custom straight eight creations, there was the Chrysler Atlantic show car from the 1990s:

The Chrysler Atlantic was a retro concept car created by Chrysler. It was first shown in 1995. The Atlantic was designed by Bob Hubbach and inspired by the Bugatti Atlantique. The idea for this car began out as a sketch on a napkin by Chrysler's president Bob Lutz in early 1993 and also involved the automaker's chief designer, Tom Gale.

The Atlantic has several similarities to the opulent vehicles of the 1930s such as the aforementioned Bugatti Type 57S Atlantique (or Atlantic). Its styling is also more than a little inspired by the Talbot-Lago T150 SS Coupe that was constructed in 1938, such as the shape of the side windows and the curved boot. Some of the retro details include a straight-8-engine that was actually constructed from two 4-cylinder Dodge Neon engines.

In reply to frenchyd :

Everything was oil-bath, though I found this MASSIVE thread of info that details how a filter can be added- including tons of other details, like head porting and what pistons work with them! A GREAT find:

https://forums.aaca.org/topic/277721-hi-performance-straight-eights/

I don't think i'll go with carbs after seeing some of the Microsquirt work Nilvacs has pulled here; but the sheer number of things I can do with the Buick engines is getting interesting (if the link is ocrrect) whereas I haven't found too much on the Packards. Might have to make a handle on the HAMB to get more opinions. So far, my pros/cons list goes:

PACKARD

+ Intake and Exhaust is on the passenger side, making routing the steering shaft easier.

+ Independent intake/exhaust ports

- L head design limits compression

- slightly heavier

BUICK

+ Pistons can be adapted from other brands (International for 320?), and from a link i've found 263 cu I8 can use Harley Pistons of some kind...

+ Some custom parts- like rocker arms- have been found.

+ 1950 and up engines use modern-style crank bearings.

+ Overhead Valve is more efficient than L head

+ Slightly lighter

+ Heavy customization has been done for the "Bombshell" Buick for Salt Flat racing so there are experts to ask.

- Siamese Intake ports. 4 holes for 8 valves.

- Intake and Exhaust is on drivers side, complicating the steering path.

Little bit of straight-eight, Lemons-style, here. And cool chatter on the subject. 

Buick used different cranks for manual trans vs automatic.

You can use the manual transmission crankshaft with the automatic but not the other way around.

The automatic crank has no provision for a pilot bearing unless you pull the crank out and have it machined yourself.

Also, be aware that IHC used cast iron pistons far longer than anyone else. If you're shopping old stock pistons, make sure you get aluminum ones.

Here's what I would do if I were you:

There's a bunch of guys in the classic car hobby (AACA full classics, not mustangs with crybaby dolls on the bumper) who have been buying 1930s and 1940s fire trucks, stripping the body off and building a roadster out of that.

You get a giant roadster which is huge amounts of fun.

Fire trucks are dirt cheap at auction because nobody wants to deal with them.

They were well maintained their whole lives.

They usually have huge engines.

We saw one in Monterey a few years ago built out of some fire engine that had an 865cid Hall-Scott engine. It had an open exhaust and sounded incredible when the guy drove away.

Probably the cheapest path.

GIRTHQUAKE said:

In reply to frenchyd :

Everything was oil-bath, though I found this MASSIVE thread of info that details how a filter can be added- including tons of other details, like head porting and what pistons work with them! A GREAT find:

https://forums.aaca.org/topic/277721-hi-performance-straight-eights/

I don't think i'll go with carbs after seeing some of the Microsquirt work Nilvacs has pulled here; but the sheer number of things I can do with the Buick engines is getting interesting (if the link is ocrrect) whereas I haven't found too much on the Packards. Might have to make a handle on the HAMB to get more opinions. So far, my pros/cons list goes:

PACKARD

+ Intake and Exhaust is on the passenger side, making routing the steering shaft easier.

+ Independent intake/exhaust ports

- L head design limits compression

- slightly heavier

BUICK

+ Pistons can be adapted from other brands (International for 320?), and from a link i've found 263 cu I8 can use Harley Pistons of some kind...

+ Some custom parts- like rocker arms- have been found.

+ 1950 and up engines use modern-style crank bearings.

+ Overhead Valve is more efficient than L head

+ Slightly lighter

+ Heavy customization has been done for the "Bombshell" Buick for Salt Flat racing so there are experts to ask.

- Siamese Intake ports. 4 holes for 8 valves.

- Intake and Exhaust is on drivers side, complicating the steering path.

The siamized intake ports of a Buick probably aren't a problem and may be an asset, depending on firing order.  What happens is anything with mass like air or fuel  tends to want to stay in motion. Not start and stop like an inlet valve forces it to do.  So once that mass gets going it will keep going if the inlet valve next to it opens soon after the other valve closes. 
 

And far as a steering shaft goes, that is easy to deal with, giving you several choices.

1st  nothing wrong with Right hand drive. 
2nd headers can go over or behind steering shaft.  
3rd steering shaft can be lowered 

4th safest of all is u joints in the shaft in the event of a front end crash you don't shove a steering column through your chest 
 

I've been sort-of wanting a late-30's Buick with the 320, from what I've read they were one of the few production cars of the era that would do 100 mph off the showroom floor.  Buick even pulled a neat trick, stuffing the big straight 8 into their smaller car, creating what could arguably be called one of the first "muscle cars".  Buick Series 60/ Century, 1936-42. 

I would love to stick two Volvo B18 engines inline, creating a 3.6 liter I8.  Output would be about 170 HP stock, with 4 SU carbs.

An acquaintance who frequented the machine shop I worked at built this monstrosity.

Starting with a Buick I-8 he bored out the cylinders for larger cylinder sleeves. Then he cut the deck down for the offset ground de-stroked crank. After fitting a new deck plate he furnace brazed the deck plate and cylinders into the block. Chevy pistons and jaguar rods, He welded 2 20R Toyota cylinder heads together and a work_of_art stainless TriY header. This was all slated to occupy a 32 ford chassis and compete on the salt In a vintage class. 

I wonder what became of that car, that was years ago (80's).

Shawn is right. Old firetrucks make rad roadsters.

If you want a motor to take apart and play around with check your mailbox:

I'm off looking for old fire trucks.

bentwrench said:

An acquaintance who frequented the machine shop I worked at built this monstrosity.

Starting with a Buick I-8 he bored out the cylinders for larger cylinder sleeves. Then he cut the deck down for the offset ground de-stroked crank. After fitting a new deck plate he furnace brazed the deck plate and cylinders into the block. Chevy pistons and jaguar rods, He welded 2 20R Toyota cylinder heads together and a work_of_art stainless TriY header. This was all slated to occupy a 32 ford chassis and compete on the salt In a vintage class. 

 

I wonder what became of that car, that was years ago (80's).

That's really interesting.  The Jaguar pistons start out at 3.600 and Buick is 3.700 .  Current racing Jaguars are over boring more and more plus maybe Chevy 283  pistons will work?  That's 3.75.  
Adapting Jaguars long rod sounds doable. 

Packard because it says thunderbolt on the head and that's cool as E36 M3

In reply to oldopelguy :

That Buick engine brings back some memories. We had a 1940 Buick on our farm, that I grew up wanting to get back on the road. I don't remember ever riding in it, but I had grand plans. I never made any real progress. I believe it was crushed when I was off in college (along with a 1957 Ford wagon and a 1960 Rambler 4-door).

In reply to oldopelguy :

I'll message you back soon, oldopelguy.

I have no idea where to look for a fire engine of that vintage. Even the oldest on eBay and GovDeals was like mid-70s.

I'm still looking for details on the inline 8 Packards; OldOpelGuy might be a big help, because I've found some random threads and little else so far. A lot of this info also is super-threatened since most of the "experts" are easily in the 70s-80s, so a good reason to go for the Thunderbolt would simply be to "preserve" the data as best as someone can. Sadly though, I find far more math and measurements on the Buick than the Packard; most recent is a page from the "Buick Fan club" or something similar which lists all the bore and stroke combinations, even the torque for all the studs! I'll post it in a little bit off my phone.

In reply to GIRTHQUAKE :

Have you seen this?  eBay linky

Not a thread I ever thought would see on our board! I love it.