1098 Engine Build - Is it a good idea?
Turbo Mini Forums

I am in need of motivation!

I just happen to have a 1098 (which I originally thought was a 998 when I got it) that I have hopes and dreams of installing a turbo on. I currently have the block at the machine shop getting cleaned up, getting the crank ground .010 under, and just placed the order for forged pistons. I am just about to place the order for all the bearings, gaskets, etc….however I am starting to get hesitant. I have seen a few successful 1098 builds on this forum; however EVERYONE I have talked to has told me not to do it. They claim the 1.75” crank is too weak and will fail! I knew there were issues with this going into it, therefore I have decided to limit the revs to 6500 RPM, add a center main strap, balance the crank, and get a half decent fluid damper.

Is this build a bad idea? Am I going to flush a couple grand down the drain? Ideally I would have found another engine to start with, however they are not easy to come by where I am located…and even if I found a rebuildable one I am probably looking at $1K just for the engine. I kind of also like the idea of doing things slightly different…but I do not want to spend anymore money if it is doomed to fail.

longer strokes make more torque and torque makes power, a turbo is a torque multiplier ..... this togeather with longer strokes ar fab!

in my opinion the cranks up to the job with a centre strap

but if you are after BHP try to get hold of a 1275 engine and start from there

Go for it, make sure the rotating assembly is balanced, and strictly keep the revs down, and it will be very torquey. In my younger days I built a 1098 based NA engine with a 12G295 head and a Piper 270 cam, it was as quick as a 1275, and pulled really well.
With the long stroke crank you get some high piston speeds so make sure you fit teflon buttons to the gudgeon pins. I had a circlip get loose which spelled the end of the 1098 engine I built.

Ben and I both have 1100 Turbo's
He is making 140banana's (hp in Aus and I am just over 130

They are absolutely brilliant to drive and blazingly quick.

I have had my issues, I definately would recommend fitting top quality parts.
Eg/ New valves (stainless) k-line the guides, good rockers, good valve springs, balance everything as mentioned.

You will love it.

Pete

1132cc Turbo ~120 bananas ATW - Fun Fun Fun

Its tosh

I have a 1098 n/a engine in the mini and its fine. People still try and swear blind that i would be better off with a 998 tho? seems they base this on the fact that 1100s rev slightly lower but with a turbo thats good isnt it?!

I too am building a 1098.
Slightly different route, as it is going to be supercharged, and the nay-sayers and woe-betiders all said the crank was too fragile. The bloke at Vmax was particularly rude to me about it. Sod 'em ! I have a good chum who has been tweaking 1100s for years, and that's good enough for me.

Metric is for people who can't do fractions.

How did I double post ??

Anyway.
I've just noticed that the original poster in this thread is in SC - my business partner and US parts store is in Cola, so if you need any bits, just shout !

Edited by Alex on 13th Jan, 2008.

Metric is for people who can't do fractions.

It was a guy at Vmax as well that swore up and down that the 1098 was a bad idea and that the crank was good for 65 hp max! Either way, I appreciate all yours posts and I have definitely decided to continue on with the 1098....

For those that have successfully built the 1098, I have a couple questions:
1. What cam did you use? I think I have settled on the ph2 from Avonbar and I have sent them an email to make sure that it will fit with no issues.
2. What sizes valves are you running with, stock or larger? I have a 12G206 which I have heard is quite rare, I am assuming the 295 valves will fit though…

Any info on what you have successfully used would help me in deciding which components to buy.

1152cc turboed mini clubman, most powerful 1.1L a-series?

http://boostmini.justboard.net/

Do they sell the RE13T online somewhere?

The 206 and 295 heaqds are indentical bar the inlet locating rings. I'd get some Minispares 26,5 exh valves to clean up the seat and get a proper valve seat radius for sure. The exh. valves will get very hot, and the standard A valves are soft as butter.

Edit: 206

Edited by Vegard on 15th Jan, 2008.

1152cc turboed mini clubman, most powerful 1.1L a-series?

http://boostmini.justboard.net/