Built engine. How hard is it?

[86 South Africa]

We all info FI adds stress on the FA20 motor which can sometimes end in tears... particularly as it’s fairly well known the rods are first to go if stressed too much.

So my question is what is a reasonably safe “built engine” made up of?
Is it as simple as new (stronger) rods and maybe some pistons, or is this much more involved?

I’m not asking so much from a labour point of view - assuming work would be done by a qualified and competent mechanic. I’m asking in terms of parts/upgrades/changes you would need to make?

[swarb]

Originally Posted by 86 South Africa

We all info FI adds stress on the FA20 motor which can sometimes end in tears... particularly as it’s fairly well known the rods are first to go if stressed too much.

So my question is what is a reasonably safe “built engine” made up of?
Is it as simple as new (stronger) rods and maybe some pistons, or is this much more involved?

I’m not asking so much from a labour point of view - assuming work would be done by a qualified and competent mechanic. I’m asking in terms of parts/upgrades/changes you would need to make?

You don't mention any power goals.
Your best bet is to go to various reputable builders' websites and look at the parts list and compare. If any of the parts are near half the expected life, it is a good idea to just replace it since it is already opened up.

[x808drifter]

Replace:
Pistons
Rods
Crank
Cams
Valve Springs/Retainers
All bearings
Sleeve Block
New Custom Filed Piston Rings
Dry Sump
ARP Hardware

Start with those.

[Tcoat]

Start with the new reinforced block from a 17.

[gtengr]

Depends on the hp goals. I would do pistons, rods, and all bearings at a minimum. Buying the hardware is the easy part, who will be putting it together and checking all clearances is the most important question.

[x808drifter]

Originally Posted by Tcoat

Start with the new reinforced block from a 17.

I'd go with the Gallo 24.

[86 South Africa]

Originally Posted by x808drifter

Replace:
Pistons
Rods
Crank
Cams
Valve Springs/Retainers
All bearings
Sleeve Block
New Custom Filed Piston Rings
Dry Sump
ARP Hardware

Start with those.

Thanks. This is sort of what I wanted to know.

Mine is currently a DD, but I may get a company car next year.... which means the FA20 could become a bit more of a playground (& learning ground) for me as I could live with it in pieces much longer if required.

It’s also clearly more involved than I first thought

[Darth Khan]

Originally Posted by Tcoat

Start with the new reinforced block from a 17.

I like the idea of this (I have a 17 so not something I need to do). My initial thoughts on this are:

(Please Note: All statements and questions are from the perspective of a reliable daily driver)

1. Why was the block strengthened? Was it decided that F.I. upgrades required it or because the standard build was weak in some areas causing normal warranty issues?
2. How much stronger is the 17 block compared to earlier versions.
3. How does it compare to historical N.A. rebuilds. (I ignore racing builds as I suspect anyone who is intending to race would need to do a complete rebuild regardless).
4. If I wanted to do a low to medium F.I. upgrade how more resilient is the 17.

[Tcoat]

Originally Posted by Darth Khan

I like the idea of this (I have a 17 so not something I need to do). My initial thoughts on this are:

(Please Note: All statements and questions are from the perspective of a reliable daily driver)

1. Why was the block strengthened? Was it decided that F.I. upgrades required it or because the standard build was weak in some areas causing normal warranty issues?
2. How much stronger is the 17 block compared to earlier versions.
3. How does it compare to historical N.A. rebuilds. (I ignore racing builds as I suspect anyone who is intending to race would need to do a complete rebuild regardless).
4. If I wanted to do a low to medium F.I. upgrade how more resilient is the 17.

Don't have the document available here but when home tonight I will pull up what was done and why. The pictures are very informative.




Edit:
I found a work around!
The critical high stress sections of the block were reinforced a the pistons hardened. I would say that in tock form the 17 engine will take moderate FI much better that the old ones. Doubt there would need to be much building required for a street car.

[gtengr]

Originally Posted by Darth Khan

4. If I wanted to do a low to medium F.I. upgrade how more resilient is the 17.

Probably marginal because it's the rods that fail first. The stiffer block should help the engine hold its geometry better under high rpm, which may tangentially increase the rod capacity a small amount, but you'll still probably have to do the rods if you want to reliably do medium FI (I'm guessing by medium you mean 12-18 psi?). My understanding is that bearing oiling also needs some attention at higher power levels (+350 rwhp or so).

[Jo0]

Originally Posted by Tcoat

Don't have the document available here but when home tonight I will pull up what was done and why. The pictures are very informative.




Edit:
I found a work around!
The critical high stress sections of the block were reinforced a the pistons hardened. I would say that in tock form the 17 engine will take moderate FI much better that the old ones. Doubt there would need to be much building required for a street car.

That's odd, if rods were the failing point, why did they only improve the pistons?

[mrspindlelegs]

Originally Posted by Jo0

That's odd, if rods were the failing point, why did they only improve the pistons?

Because rod failure has not been a problem with the naturally aspirated engine that they install from the factory. We are on our own when it comes to the engine being reliable under boost.

[15limited]

Originally Posted by Jo0

That's odd, if rods were the failing point, why did they only improve the pistons?

It would seem from the two pictures given this was only from an OEM NA perspective, and I believe gtengr was talking from a FI standpoint.

Sent from my 2PQ93 using Tapatalk

[Tcoat]

Originally Posted by Jo0

That's odd, if rods were the failing point, why did they only improve the pistons?

The rods may have been the failure point but that does not mean they were the root cause. The piston heads may have been warping causing the rods to fail or even the block may have been letting the crank twist under power which again could cause the rods to fail. (these are just examples of what COULD have been the root cause I am not saying either is remotely true since I am not privy to their FMEA engineering reports). The parts that fail in a mechanical system are not always the ones at fault. In fact, it has been my experience, that the parts that fail are very rarely the cause.