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How to increase b21ft compression ratio?

Redwood Chair said:
I think you should because what you're saying about old Volvos isn't adding up.

Or simply buy that AE86 you seem to lust after, and go bug the guys on the Toyota forums.

:-P
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I've been on the market for one for 4 years, only ones that pop are beat to hell by wannabe teen drifters who the try to resell the car after its become FUBAR for 5x what they bought it for.
 
bobxyz said:
You can replace the original deep dish B21FT pistons with shallower dish B21A pistons, but you'll most likely need to buy a set new and have the block machined. Doing a B230FT engine swap, or just buying a 740T, are more practical.

The B21FTs will have a SCR of ~8.0:1, the B21As will get SCR up to ~9.5:1. http://forums.turbobricks.com/showthread.php?p=5421139
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Wow, very helpful! Might just go this route, I wonder how the pistons will deal with boost tho.
 
740atl said:
Aside from milling the surface of the block, use a thinner head gasket.

Or, do nothing and just raise the boost. Low comp loves boost.
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Thinner headgasket meh realistically you have to leave something around 030, so going down from 044 to 030 ain't gonna do squat..Old B21 and B23 leave the piston down the bore a goodly amount--on paper around 027 below deck.. can't see the guy decking the block with no tools, no garage..

That leaves your answer...Keep the T cam cause that gets you the most static comp with its modest intake valve closing, and UP THE BEWST..
 
Keep the t cam and throw on a 15g or a 16t on the cheap and have fun. I had a stock b21ft and a 16t with a t cam in my old Toyota and it was alot of fun
 
IWantedAnAE86 said:
Gas isn't that cheap here in BC Canada, AND MAYBE I WILL!
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There are plenty of 240s down here in th Unexplored Southern Area but 240 turbos are a less common...

Importing a car from the Unexplored Southern Area is evidently pretty easy as at least 5-6 cars have gone up to Kanuckistan from right here...

Ultimately the root of all unhappiness is desire, so desiring teverything = unhappiness..
The thing you are simply going to have to learn to do is work on cars and build the car that suits your taste... Look at Volvos as just a bigger Toiletta Commodah...

Anything a AE86 can do, you can make a 240 do only better and cheaper.

IF you can work on a car..
so given that you have desire to have a fun car what are you doing to remedy the lack of tools and lack of garage space?

THAT is the harder part---the path to enlightenment is clear and known, that's the easy part..

What are you doing? is the hard part.

Where in Bee Sea are you?
You want a pimpy boulevard cruiser? a FUN!:omg: road car? A gravel road fun machine?
 
John V said:
There are plenty of 240s down here in th Unexplored Southern Area but 240 turbos are a less common...

Importing a car from the Unexplored Southern Area is evidently pretty easy as at least 5-6 cars have gone up to Kanuckistan from right here...

Ultimately the root of all unhappiness is desire, so desiring teverything = unhappiness..
The thing you are simply going to have to learn to do is work on cars and build the car that suits your taste... Look at Volvos as just a bigger Toiletta Commodah...

Anything a AE86 can do, you can make a 240 do only better and cheaper.

IF you can work on a car..
so given that you have desire to have a fun car what are you doing to remedy the lack of tools and lack of garage space?

THAT is the harder part---the path to enlightenment is clear and known, that's the easy part..

What are you doing? is the hard part.

Where in Bee Sea are you?
You want a pimpy boulevard cruiser? a FUN!:omg: road car? A gravel road fun machine?
Click to expand...

I have experience working on vehicles, small things such as swapping turbos, cams, exhausts are not a problem for me. It's just the larger things such as pulling an engine out completely and swapping in another that would not be possible.

And pffffffff... Just like the 86, I love Volvos with all my heart, but the ae86 and 240/740 are completely different animals. The 86 is only 2200lb and has a 1.6L dohc that can rev to the moon and back, can be stroked to 1.8L for <$100 and has a much, much larger aftermarket store. But they are rare and like I said often beat to sh*t.

As for 240, if I can find one that's not some young kids drift sl00t, I might go with the b21a pistons, V cam, and slightly thicker head gasket, trying to bring as close to a 9:1 compression ratio as I can.

I really appreciate everyone's help on this, even the ones that were trying to he smarty pants. Also Prius > 240.
 
IWantedAnAE86 said:
I have experience working on vehicles, small things such as swapping turbos, cams, exhausts are not a problem for me. It's just the larger things such as pulling an engine out completely and swapping in another that would not be possible.

And pffffffff... Just like the 86, I love Volvos with all my heart, but the ae86 and 240/740 are completely different animals. The 86 is only 2200lb and has a 1.6L dohc that can rev to the moon and back, can be stroked to 1.8L for <$100 and has a much, much larger aftermarket store. But they are rare and like I said often beat to sh*t.

As for 240, if I can find one that's not some young kids drift sl00t, I might go with the b21a pistons, V cam, and slightly thicker head gasket, trying to bring as close to a 9:1 compression ratio as I can.

I really appreciate everyone's help on this, even the ones that were trying to he smarty pants. Also Prius > 240.
Click to expand...


Anything a AE86 can do, the 240 can do better and cheaper.. Look at this nice little clip

<iframe width="560" height="315" src="https://www.youtube.com/embed/g5U6cwX8RcE" frameborder="0" allowfullscreen></iframe>

To do that in BOTH cases reliably you have to do the same things.. build a motor, put a clutch on it, a good gearbox, a stronger axle and LSD get good suspension--and quicker steering and better brakes..

Now realistically you make it 1800 easy enough ("i've built 'em and suplied LOTS! of parts to AE86s pervs around the world)( I do like 'em) What kinda of ft/lbs you think it could make? 145?.....Spend LESS money on a Volvo and you can do way more HP and more importantly, just cause its bigger, a LOT more ft/lbs..

More ft/lbs at less revs means its less stressed...Means it lasts longer..Important thing for a privat driver.. 25 years ago cars like that in the vid had typically about 230-235hp @7000 rpm...A 4AGE making that is going to be a $20,000 build doing 10,000 rpm..

I push 240s for rally which my only interest in cars...I have saying long enough that its become a "saying" and I acknowledge that the MkII Escort in Group 4 spec is the coolest car in all human history, (and everybody knows AE86s is a virtual copy of a Ford Escort with Ford BDA, it is, and it was intentional) but I say the 240 is "The Escort of North America".. Build it like an Escort, and it'll go like an Escort...only fitting North American conditions better...
(we have a lot bigger trees and bigger roads and higher speeds because of the roads built to get those trees out of the mountains)..

Now...go find a 240. Building engines is 75% maniacal cleaning 15% measuring dead accurate, then 10% assembly...It is NOT rocket science..

of course it costs money but you work, dontcha?
 
Yoshifab sell the Cometic head gaskets now. They are not cheap. Never have been. But it is a good gasket.

Pull head, measure deck height, get thinnest head gasket you can run safely, shave the **** out of the head. You might get to 8.5:1. More if you get really carried away with the head and run a shorter timing belt.
 
John V said:
Anything a AE86 can do, the 240 can do better and cheaper.. Look at this nice little clip

<iframe width="560" height="315" src="https://www.youtube.com/embed/g5U6cwX8RcE" frameborder="0" allowfullscreen></iframe>

To do that in BOTH cases reliably you have to do the same things.. build a motor, put a clutch on it, a good gearbox, a stronger axle and LSD get good suspension--and quicker steering and better brakes..

Now realistically you make it 1800 easy enough ("i've built 'em and suplied LOTS! of parts to AE86s pervs around the world)( I do like 'em) What kinda of ft/lbs you think it could make? 145?.....Spend LESS money on a Volvo and you can do way more HP and more importantly, just cause its bigger, a LOT more ft/lbs..

More ft/lbs at less revs means its less stressed...Means it lasts longer..Important thing for a privat driver.. 25 years ago cars like that in the vid had typically about 230-235hp @7000 rpm...A 4AGE making that is going to be a $20,000 build doing 10,000 rpm..

I push 240s for rally which my only interest in cars...I have saying long enough that its become a "saying" and I acknowledge that the MkII Escort in Group 4 spec is the coolest car in all human history, (and everybody knows AE86s is a virtual copy of a Ford Escort with Ford BDA, it is, and it was intentional) but I say the 240 is "The Escort of North America".. Build it like an Escort, and it'll go like an Escort...only fitting North American conditions better...
(we have a lot bigger trees and bigger roads and higher speeds because of the roads built to get those trees out of the mountains)..

Now...go find a 240. Building engines is 75% maniacal cleaning 15% measuring dead accurate, then 10% assembly...It is NOT rocket science..

of course it costs money but you work, dontcha?
Click to expand...

Look I'm not gonna turn this into a 240 vs ae86 argue, but saying that the 240 can do anything the ae86 can do better and for cheaper is outright wrong. They both have their strong and weak points.

As for the 4ag motor, there are plenty of builders making 260+hp at under 9k RPMs naturally aspirated, and the 7ag stroker motors go further than that. They also make plenty of power boosted, I've seen a twin charged 4age making 500+hp with the stock 1.6L displacement and even more when stroked to 1.8L.

Making power with those motors are cheap and easy as well, if you have an ae86, swap in a 4agze bottom end ($100-150), custom fab your own turbo kit (let's say around $500), put some crazy boost into and you'll be in the 250+hp range. Throw in a set of cams, up the boost even more you'll be pushing crazy numbers for a tiny motor. These DOHC motors breathe extremely well. If your tranny goes out, throw in a cheap W58 from a supra and call it a day.

Even with all the hp potential, you still don't even need that much power for something that can be stripped to sub-1800lb.

This is the last time I'll say it, the ae86 and 240 are completely different animals. It's like comparing apples to oranges.

And please explain to me how the 86 is a copy of an escort.
 
I don't know what all this nonsense is about, the T cam pulls good from way down low and the 240T will run just fine on regular gas if you don't tweak it out.

Besides Oh Pee doesn't even have a car yet so I call :benchrace:.
 
And I don't agree with it's a waste of money either. You can increase timing with super and get better performance AND better gas mileage. Usually 2-4mpg better.

Take some average numbers and do some easy math:

25mpg on super for 10 gallons = 250 miles. At $3 a gallon that's $30.
22mpg on regular for 10 gallons = 220 miles. At $2.60 a gallon that's $26.

A long road trip of lets say 2000 miles. $240 in super or $237 in regular.

Are you really worried about $3 over 2000 miles?
 
Redwood Chair said:
I don't know what all this nonsense is about, the T cam pulls good from way down low and the 240T will run just fine on regular gas if you don't tweak it out.

Besides Oh Pee doesn't even have a car yet so I call :benchrace:.
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I have a car and two trucks. All are slow and boring.
 
Tuff240 said:
And I don't agree with it's a waste of money either. You can increase timing with super and get better performance AND better gas mileage. Usually 2-4mpg better.

Take some average numbers and do some easy math:

25mpg on super for 10 gallons = 250 miles. At $3 a gallon that's $30.
22mpg on regular for 10 gallons = 220 miles. At $2.60 a gallon that's $26.

A long road trip of lets say 2000 miles. $240 in super or $237 in regular.

Are you really worried about $3 over 2000 miles?
Click to expand...


I get 25mpg at 60 mph whether I use super or not.
 
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