S4 Budge stroke engine build question??
#1
Instructor
Thread Starter
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I have 3 engines in hand (all need rebuild), and going to keep one engine for my S4
I want to build NA stroke engine with ITB (I need at least 400HPs), I am planning to spend 10Kon parts.
What kind parts I should keep for these 3 engines?
1.87 S4
2.90 S4
3.85 Row
Need your guy’s input
Many thanks!
I want to build NA stroke engine with ITB (I need at least 400HPs), I am planning to spend 10Kon parts.
What kind parts I should keep for these 3 engines?
1.87 S4
2.90 S4
3.85 Row
Need your guy’s input
Many thanks!
#2
Rennlist Member
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If you're going to bore the block you'll want to measure wall thickness. The '85 will most likely be the best candidate. They have a reputation of having thicker wall castings then the later S4's.
The heads off the '90 have thicker bosses for the headbolts, so may be the best choice for heads.
Although you don't have one, the oil pan baffle/pickup set up out of a '78/'79 is popular for its oil control characteristics. Everything else is going to get tossed in a stroker project, so the rest of the parts don't really matter.
The only other observation I can make is that when you use the words "budget" and "stroker engine" in the same sentence, you can almost consistently exchange the word "expensive" for "budget" and "grenade" for "stroker engine" and come away with the same meaning.
The heads off the '90 have thicker bosses for the headbolts, so may be the best choice for heads.
Although you don't have one, the oil pan baffle/pickup set up out of a '78/'79 is popular for its oil control characteristics. Everything else is going to get tossed in a stroker project, so the rest of the parts don't really matter.
The only other observation I can make is that when you use the words "budget" and "stroker engine" in the same sentence, you can almost consistently exchange the word "expensive" for "budget" and "grenade" for "stroker engine" and come away with the same meaning.
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#3
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Block from the '85 (theoretically thicker cylinder walls), heads from the '90 (definitely thicker bosses around the head bolt holes) .
Unless the exchange rate between Taiwan and the U.S is a lot better than I think it is, you're going to spend a lot more than $10K on parts. Just the crank, rods, pistons, and bored/nikasiled block will be $10K. An ITB setup is at least a $3-4K proposition, just the pieces themselves.
Unless the exchange rate between Taiwan and the U.S is a lot better than I think it is, you're going to spend a lot more than $10K on parts. Just the crank, rods, pistons, and bored/nikasiled block will be $10K. An ITB setup is at least a $3-4K proposition, just the pieces themselves.
#5
Nordschleife Master
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85 Row most likely is a 4.7 block, not a good choice vs 5.0 later block is it?
Normal stroker very unlikely with less than $20k.
Maybe if you keep stock pistons and just add a stroker crank, making something like a 5.5L instead of 6.4L (stroked and bored), then add better cams and some head and intake work?
Normal stroker very unlikely with less than $20k.
Maybe if you keep stock pistons and just add a stroker crank, making something like a 5.5L instead of 6.4L (stroked and bored), then add better cams and some head and intake work?
#6
Nordschleife Master
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I have 3 engines in hand (all need rebuild), and going to keep one engine for my S4
I want to build NA stroke engine with ITB (I need at least 400HPs), I am planning to spend 10Kon parts.
What kind parts I should keep for these 3 engines?
1.87 S4
2.90 S4
3.85 Row
Need your guy’s input
Many thanks!
I want to build NA stroke engine with ITB (I need at least 400HPs), I am planning to spend 10Kon parts.
What kind parts I should keep for these 3 engines?
1.87 S4
2.90 S4
3.85 Row
Need your guy’s input
Many thanks!
- GTS crankshaft (i.e. bump to 5.4L)
- Custom cams from one of the custom cams providers here on Rennlist
- ITB setup and custom intake
- Sharktuner Alpha (i.e. using MAP sensor - so no need to worry about MAF during intake design)
Keep the 87 engine for spares in case you blow up the 90 engine - but the 90 has better heads, better pistons (higher compression), and possibly the GT-style rods, so I'd stick with the 90 engine as a whole.
If that all goes swimmingly and you're not happy with the result, buy some used Porsche 968 pistons and have the 87's block bored out to 103mm (giving 6.0L from memory), then transplant the heads/intake/pistons/crank off the 90 engine.
However I'd start with the route that doesn't involve boring the block (GTS are also 100mm bores, like the 5.0L engines - so the GTS crank is a "stroker crank"), as once you start boring Alusil, you're opening yourself up to a whole lot of risk relating to your workshop's experience and availability of correct tools/materials to correctly finish the newly-bored cylinders in an alusil block (its not done with a cross hatch and stones like iron blocks).
Last edited by Hilton; 10-19-2011 at 05:47 AM.
#7
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So I could have put a gtd crank and some cams in my s4 when I jd the engi be apart and had a hybrid 5.5l? Has anyone done this
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#8
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1. GTS crank + GTS rods 2nd hand - several sellers here on rennlist asking around $2000
2. Bore the block to 104mm - no idea of costs of doing this outside of the UK
3. Custom 104mm pistons from JE Pistons designed to run in alusil bores - $1550
Gives you 6.0ltrs displacement... Almost as good as a 6.5ltr stroker minus the headaches of custom crank, rods and pistons
#10
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#12
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Thanks you guys input. That really help me.
To Bore the block in Taiwan is very cheap about 200USD, but the hardest thing is balanced crank with piston, I can not find factory who has experience.(Is that really hard?)
I think I might stay same block with stroke crank, make it to 6L
Another question, Is ITB can gain any HP?
To Bore the block in Taiwan is very cheap about 200USD, but the hardest thing is balanced crank with piston, I can not find factory who has experience.(Is that really hard?)
I think I might stay same block with stroke crank, make it to 6L
Another question, Is ITB can gain any HP?
#13
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1. Put 20K in an account for your budget stroker build
2. Add more money when you run out.
This is especially true if you are building your 1st stroker engine.
Don't even try the itb route yet.
2. Add more money when you run out.
This is especially true if you are building your 1st stroker engine.
Don't even try the itb route yet.
#14
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Thanks you guys input. That really help me.
To Bore the block in Taiwan is very cheap about 200USD, but the hardest thing is balanced crank with piston, I can not find factory who has experience.(Is that really hard?)
I think I might stay same block with stroke crank, make it to 6L
Another question, Is ITB can gain any HP?
To Bore the block in Taiwan is very cheap about 200USD, but the hardest thing is balanced crank with piston, I can not find factory who has experience.(Is that really hard?)
I think I might stay same block with stroke crank, make it to 6L
Another question, Is ITB can gain any HP?