20v 4age VS 20v 7age

[v33sonata]

So if any of you read my other post you know I need to do something with my motor. I have a brand new rebuilt 20v BT head and 2 dead blocks. I have a 20v BT block with rod knock that I can rebuild or I have a fully forged 7a block from my old turbo project I can get a new set of custom piston for and do a hybrid 7age 20vbt. Any suggestions anyone? Has anyone here ever done a 7age 20vbt? What do you suspect might be the differences between the 2. Lets hear your thoughts.

[v33sonata]

Also where can I find rods for the 20v?

[krammit the frog]

Never been a fan of frankenmotors. I'd rather get something that was designed by someone who really knows what they are doing.

Think about how much you will dump into getting maybe 150 whp out of a 7age reliably and think of how much power you could make with a factory motor with easy parts availability. Just my take on that subject.

[v33sonata]

Never been a fan of frankenmotors. I'd rather get something that was designed by someone who really knows what they are doing.

Think about how much you will dump into getting maybe 150 whp out of a 7age reliably and think of how much power you could make with a factory motor with easy parts availability. Just my take on that subject.

Hey 150hp is 150hp LOL! I wouldnt have to dump much more into either or motor to make it work. I also have no idea where to source BT parts if needed. I do appreciate the input! Anyone else...........

[krammit the frog]

Yeah, 150 is 150, but you can spend a bit more and put in something like a 1uz to get over 200 with a lot more torque.

[yoshimitsuspeed]

As for parts it really depends on what you are looking for. Some things can be hard to find but mostly only top end stuff.
You asked about rods. Any 7 rib 4AGE rods will work fine. Only ones that won't are the early 3 rib rods with 18mm wrist pins.
The 20mm LP, SP and silvertop rods are a little heavier than BT rods but all are very strong and will work fine.
I am generally not a fan of 7A builds. I have yet to see one that could beat a stock 2ZZ and the time and money they require to get there just seems silly to me.
Since you have most of the parts including what sounds like a pretty sweet bottom end the idea makes a little more sense but I'm still not a huge fan.
I disagree with Krammit's general logic because some hybrids have proven to be a great idea. The 5SGTE for example. The 7A on the other hand has never proven to be terribly impressive. I think mostly because most people try to half ass the build and take shortcuts that equate to unimpressive numbers. On top of that it's still just 1.8 liters.
You say the 1.8 was from a turbo project though so I am hoping that you would be thinking of boosting this motor?

[v33sonata]

Yeah, 150 is 150, but you can spend a bit more and put in something like a 1uz to get over 200 with a lot more torque.

Already had a turbo ,motor with over 250hp. definably not looking to do a V8 swap as that would be much more in money to do then a simply rebuild of the current engines I have.

[v33sonata]

As for parts it really depends on what you are looking for. Some things can be hard to find but mostly only top end stuff.
You asked about rods. Any 7 rib 4AGE rods will work fine. Only ones that won't are the early 3 rib rods with 18mm wrist pins.
The 20mm LP, SP and silvertop rods are a little heavier than BT rods but all are very strong and will work fine.
I am generally not a fan of 7A builds. I have yet to see one that could beat a stock 2ZZ and the time and money they require to get there just seems silly to me.
Since you have most of the parts including what sounds like a pretty sweet bottom end the idea makes a little more sense but I'm still not a huge fan.
I disagree with Krammit's general logic because some hybrids have proven to be a great idea. The 5SGTE for example. The 7A on the other hand has never proven to be terribly impressive. I think mostly because most people try to half ass the build and take shortcuts that equate to unimpressive numbers. On top of that it's still just 1.8 liters.
You say the 1.8 was from a turbo project though so I am hoping that you would be thinking of boosting this motor?

Good info. True the 7a is an odd ball build with out huge gains for the cost. The only reason I am considering it is due to having the block in the garage now with all the goodies on it. Yes its only a 1.8L (closer to 1.9L now) but the BT is only a 1.6L. As for turboing it. I have been there and not going down that road again. Thats the hole reason I got a BT to begin with was to dump the turbo. What does LP and SP mean?

[s24a]

LP = Large Port
SP = Small Port

Large Ports were early 4AGEs with the secondary intake tuning plate assembly to cut off one of the runners in the intake manifold.
The Small Port engines did not need this device and dispensed with it.

[yoshimitsuspeed]

I have been there and not going down that road again.

Why not? Sounds like you have most everything you need for a badass setup.

[v33sonata]

I have been there and not going down that road again.

Why not? Sounds like you have most everything you need for a badass setup.

I just parted it all out casue. Just sold the turbo and my FMIC stuff. Things kept breaking. Alot! No more turbo's for this 86. LOL

[yoshimitsuspeed]

I have been there and not going down that road again.

Why not? Sounds like you have most everything you need for a badass setup.

I just parted it all out casue. Just sold the turbo and my FMIC stuff. Things kept breaking. Alot! No more turbo's for this 86. LOL

What kept breaking?
A good modest turbo build should go for 100k miles.
If you are going for crazy numbers like 350+ hp then it's expected to break parts but if you are comparing a 165 hp 20v to say a 220 HP turbo they should both live a long happy life assuming they both have a good tune.
What kept breaking and how hard were you pushing it?

[v33sonata]

Lets get back on topic. LOL. Go ahead and look at some of my old posts.

7a vs 4a BT...........

[Evo_lucian]

My vote is for 7a. No need for custom pistons, stock 4ag pistons will do. The torque increase from the 7a will be worth the trouble.

[oldeskewltoy]

concerning "tall block" (7AG) builds... you just need to know what you are doing.... Proper 7AG builds can easily make 175+hp and well over 150#/ft....

[v33sonata]

I have to do custom pistons due to the rods I am using. I think 7a it is