A few questions about my 998 turbo plans
Turbo Mini Forums

Hi,
i just have a few questions about my planned 998 turbo build.
I am hoping to run 10 or so psi to give me about a 100bhp road engine.
I plan to rebuild the engine and maybe fit bigger pistons (+40) and go with a standerd gearbox with a minispares cross pin diff.

-i was wondering if there is need to rebuild the gearbox,
-also i have a verto clutch (well i think it is, its a 86 mayfair) so is changing to pre verto a must.
i have read on another topic that you can use a turbo verto cover and a non-sprung centre as a cheaper option, but what does this actually alow you to do,
-I was thinking of fitting larger valves in the 12g295 head i have, what size would work well and wheres the best place to buy them.
-Is there need to get anything fancy done to the crankshaft or is it ok as it is.
-when rebuilding the engine will all standard bearings and bits be up to the job and what about rocker assembly and pushrods.
-i was also thinking of fitting a fibreglass flip front, what are your views on them, do the affect handling with the extra weight loss.
Im on a bit of a tight budget but dont want to sacrafice reliability for an extra few pounds.
Im a complete novice when it come to engines so sorry for all the questions.
Any help appreciated

A job worth doing is a job worth over doing

I can answer some of your questions:

"-i was wondering if there is need to rebuild the gearbox,"

If the box has done a lot of hard road miles then it may not last long.

"-also i have a verto clutch (well i think it is, its a 86 mayfair) so is changing to pre verto a must.
i have read on another topic that you can use a turbo verto cover and a non-sprung centre as a cheaper option, but what does this actually alow you to do,"

A heavy duty verto as sold by MED/Min-its/Minispares will hold over 100 lbft, so should be fine. use with an unsprung driven plate.

"-I was thinking of fitting larger valves in the 12g295 head i have, what size would work well and wheres the best place to buy them."

No need for larger valves for 100hp. i run standard size valves in an unported head and get 120hp. Minispares do standard size valves in stainless C-AEG587 & C-AEG588.

"-Is there need to get anything fancy done to the crankshaft or is it ok as it is."

Standard crank is fine. Balancing will help.

"-when rebuilding the engine will all standard bearings and bits be up to the job and what about rocker assembly and pushrods."

Use VP2 bearings if you can get them (you may need to modify the main caps for the VP733 bearings). Standard pushrods and rockers will be fine.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Thanks for the reply,

Would this clutch do the job ok.
http://www.minispares.com/Product.aspx?ty=...id=38496&title=
And is there need to get an upgraded pressure plate, and what do you mean by an unsprung driven plate (like i said earlier , im a complete novice) :). I never stripped an engine down or anything so its all new to me.

The valves in the 12g295 head i have are sitting a bit low, not sure were they change and lapped incorrectly but they aint sitting right, so i was going to fit larger ones any way, or would i be better off fitting unleaded valve seats and going with standard size valves.

I also plan with going with a gt1544 turbo and i was wondering would using this smaller turbo over a T2 effect the power by much.

Also where is the best place to get any bits i need, minispares seems the most popular but are a bit more expensive in some stuff than other places.

A job worth doing is a job worth over doing

That MS clutch you list is an unsprung driven plate.

This is the heavy duty verto clutch that I was talking about:

http://www.minispares.com/Product.aspx?ty=...id=42699&title=

Most standard 12G295 valves look sunk into the head. Not surprising if they have already covered a lifetime of use. My choice would be to get unleaded seats fitted and use the valves listed above.

Have a search for GT1544, there was a useful discussion only recently.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Thanks for the help Paul, cleared up a few things that were puzzling me, probally go with the a few of the bits you mentioned and see how it goes.

A job worth doing is a job worth over doing