998 engine spec ADVICE NEEDED! i'm a complete novice engine builder
Turbo Mini Forums

Hi, i've just stripped my A+ 998 engine & box, all bolts have come out nicely, i'm just degreasing all the parts to then take for machining, if & where needed

i'm planning on going to morespeed or if you have a better recommendation in the midlands plz advize! i have someone to check the gearbox for me although i may strip it 'i'll see how brave i'm feeling' Anyhow my planned spec is as follows:

A+998 block: acid dipped to clean inside and out, valve pockets in the block added for future 940 head (maybe) rebore if needed! also can i have a centre main strap on the 998 block, just not heard of this on here yet!

crank, rods & flywheel: crank reground if needed, rods checked! i may polish the rods myself going by the vizard book, flywheel checked & the hole assembly fully lightend & balanced

pistons: not sure if i should go for dished or flat top or what type?

cam: mine is standard slot drive, i'm not sure with this at all!!!

oil pump: will i get a high capacity 998 pump or metty turbo, or is there better

clutch: Not sure what to do/go for

295 head converted to unleaded, i'm not sure if there are specific mods needed for the turbo setup as its 28cc as standard going by the vizard book

timing: either vernier duplex or vernier belt drive, what do you think?

standard rockers at the moment but may get some kieth dodd 1.5.1 ratio jobbys

gearbox: sticking with the standard helical setup just a full recon with a centre oil pickup-pipe & uprated diff pin, if the budget allows i may get 1.1 ratio SC drop gears, what final drive should i go for? i'm staying with 10" wheels & in my wishful thoughts i'd like to be able to do 1/4mile in 15.5

to start i'll stick with the standard dizzy with aldon ignitor but what else should i do ignition wise? i am thinking over the idea of megasquirt for the reliability/smoothness/power aspect, just depends on if i have enough in the back pocket!

obviously new bearings cam followers & perishable/high wear items

i'll be running mirage manifolds with a T2 & S2rs turbo intercooler & a metro radiator front mounted

this is my 1st ever engine build!!! a little much to start off with maybe but 'what the heck' its going in my daily driver so just aiming for a hard-wearing powerfull-ish fast road car that'll give a suprise or to on track days & the drag strip

i need some pointers guys, cheers

Edited by clubminiflip on 23rd Aug, 2006.

SKYLINES ARE LIKE CLITS, EVERY FLANGE SEEMS TO HAVE ONE: see this sticker on my silvia

the Search-section on this forum is blummin superb & simple to use, unlike some other forums, without the search-section & the help of this bunch of chaps on here i'll never be able to !!!Start the day with a 998cc turbo!!! :) i'm getting closer though!

Tom Fenton says: I have it all, make me an offer

Pockets for 12G940 head- only have these done if you are going to use a 1275 head straight away. If not don't have them done.

is this due to it dropping the CR or another reason, i was just going to do it incase i put a 940 o in the future, its not a problem if i cant, i'd build a spare 998 block with pockets, if there is a specific reason tho let me know, cheers

SKYLINES ARE LIKE CLITS, EVERY FLANGE SEEMS TO HAVE ONE: see this sticker on my silvia

the Search-section on this forum is blummin superb & simple to use, unlike some other forums, without the search-section & the help of this bunch of chaps on here i'll never be able to !!!Start the day with a 998cc turbo!!! :) i'm getting closer though!

Tom Fenton says: I have it all, make me an offer

Well check out the speck of our engine for a start:
http://www.twin-turbo.co.uk/The%20Spec.html

A cetnre mani strap can be fitted to a 998 and is advisable. Make sure that when the strap is fitted that it still locates the thrust bearing properlu. If it doesn't then it will not last long.

I would not personally put pockets in for you are not using a 940 head.

A high capacity 998 oil pump will be fine.

An MG metro cam works wonders with our engine so that i sall I can advise. Stay away from turbo cams designed for 1275+ as they don't work n the 998.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

benh cheers, i think i'll be going with the centre main strapp then, i just was'nt 100% sure,

morspeeds should be able to do this mod properly so the thrusts locate as they should, should'nt they,
i'm only going on the reputation that a few have said they are good but if anyone can give a personal recommendation PM me

can i get an mg metty cam new or as a regrind? if i could find a mint one 2nd hand obvously that is prefered :oP

rob walker was also recommended to me for my machine work &
autosprint which i think is birmingham based?

do you think i'm heading down the right road with my spec, i'm not after big power, but a nice rounded engine, just the few issues listed above that i'm confused with, i've put them all in this thread rather than doing lots of posts, cheers

Edited by clubminiflip on 23rd Aug, 2006.

SKYLINES ARE LIKE CLITS, EVERY FLANGE SEEMS TO HAVE ONE: see this sticker on my silvia

the Search-section on this forum is blummin superb & simple to use, unlike some other forums, without the search-section & the help of this bunch of chaps on here i'll never be able to !!!Start the day with a 998cc turbo!!! :) i'm getting closer though!

Tom Fenton says: I have it all, make me an offer

I'd use flat top pistons if you are going to use the 12G295 head. The new Minispares Mega ones should be available soon.

If you use a 12G940 head with standard chambers, then you will need dished pistons to get the compression down. The 20773 dished pistons have been proven by Wil & Ben.

Personally, I am going to use the standard cam because I believe it will give good torque at low revs which is what you need for a fast road car.

Edited by Paul S on 23rd Aug, 2006.

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."

been reading the vizard bible again tonight! i think i may give the rod polishing (ooh-eer) idea a miss as i'm a novice to engine building and with this build i dont think its really neseccerry 'but' i think i'll make the point of possibly having the rods balanced end to end & make the point to the machine shop i choose to check for ovaling of the rod ends! & the on the block caps that they are inline & round/correct!

axel: what would be the differance between the standard cam & mg cam, would an SW5 work well at all???
i'd like to have a quite a broad power-band when on boost possibly from 2000rpm to ?
i'd like my car to be high-revving,

my 'complete novice' theory is: if the engine can rev well/easily & to a high rpm its making consistant exhaust gas to keep the turbo spinning consistently in the optimum boost amount, there for not laggy? i'm probobly wrong but i'm allowed :oP hehe!

what clutch should i be looking at, i'm sticking with my verto setup

plz guys have a check of my 1st post so i can clear up my question marks/gripes, i'm gettin a bit nervous as i'll be finalising my spec then its machine shop time, this is a lil scary to me but i feel confident & have plenty of 'panel wipe' for cleaning and oil for assembly oh that reminds me do i need specific lubes for engine assembly?

Edited by clubminiflip on 23rd Aug, 2006.

SKYLINES ARE LIKE CLITS, EVERY FLANGE SEEMS TO HAVE ONE: see this sticker on my silvia

the Search-section on this forum is blummin superb & simple to use, unlike some other forums, without the search-section & the help of this bunch of chaps on here i'll never be able to !!!Start the day with a 998cc turbo!!! :) i'm getting closer though!

Tom Fenton says: I have it all, make me an offer

i've read on here that alot of 998 turbos that ppl have done stick with the standard cam but i've also read that the SW5 in most road going NA applications is a really good choice, i dont feel i'll need top end for the drag strip as you try to change gear before the power drops off (usually top end) so the sw5 is on the maybe list if you've had decent results, what would it rev to?

what flat top pistons would i be looking at?

i'll be making notes now for the head mods & i now have my reading homework in the vizard book for tomorrow, i'll go with that advice 1071s as the guides need changing + i have some 1275 valves in the garage i think they are standard 1275 ones, will these be ok, also do i re-use the double valve springs from the 295 head

what sort of boost would be possible with this setup? i have a good S2rsturbo intercooler for boost temp reduction

clutch-wise a turbo clutch cover, what spec plate? cheers

THE a4 sheet is filling up fast :oP

Edited by clubminiflip on 24th Aug, 2006.

SKYLINES ARE LIKE CLITS, EVERY FLANGE SEEMS TO HAVE ONE: see this sticker on my silvia

the Search-section on this forum is blummin superb & simple to use, unlike some other forums, without the search-section & the help of this bunch of chaps on here i'll never be able to !!!Start the day with a 998cc turbo!!! :) i'm getting closer though!

Tom Fenton says: I have it all, make me an offer

Also reading the vizard book it says the metro turbo rad has 50% more capacity than it needs to keep the metty turbo motor cool, is my thinking correct that this could be a cheap cooling option if i front mount it in my 998 turbo mini, it has to be cheaper than an uprated mini rad?

SKYLINES ARE LIKE CLITS, EVERY FLANGE SEEMS TO HAVE ONE: see this sticker on my silvia

the Search-section on this forum is blummin superb & simple to use, unlike some other forums, without the search-section & the help of this bunch of chaps on here i'll never be able to !!!Start the day with a 998cc turbo!!! :) i'm getting closer though!

Tom Fenton says: I have it all, make me an offer

For the machining that you want any local machine shop should be able to do what you want. there's no point lugging an engine around the country for simple stuff. Porting and fancy head work is Simons skill, so use him for that.

Buy the centre strap of Morspeed though then you can just get the cap machined flat as Morspeeds straps have the tab location in them.

1.5 rockers work well on our car, but for what you want stick with the standard ratio as it should improve low down torque. And for as road car stick with a chain to drive the cam. IMO the later standard 'simplex' chain with the tentioner is more than enough (nice and light too).

The MG metro cam can be had from Kent as a regrind, its badged a KC500.

Is there any more questions I've missed that haven't already been covered?

Wil

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

right i think i have the basics for getting the block crank rods & pistons, sorted,

any clutch help would be good, what to use? i'm staying with the verto setup but with the outer casing drilled with a few holes to let the heat out quicker from the clutch plate for those fast starts at the strip

gearbox check what i've come up with above, is the spec enough?

it it worth having the block & box drilled for the 5/16 bolts

i think i'll go with the vernier duplex setup so i can adjest the cam timing a little to get perfect!

last and most importent What Ignition? i'd like to stay with the dizzy, but what works best initially, cheers

SKYLINES ARE LIKE CLITS, EVERY FLANGE SEEMS TO HAVE ONE: see this sticker on my silvia

the Search-section on this forum is blummin superb & simple to use, unlike some other forums, without the search-section & the help of this bunch of chaps on here i'll never be able to !!!Start the day with a 998cc turbo!!! :) i'm getting closer though!

Tom Fenton says: I have it all, make me an offer

right i've got my initial quote from simon at morspeeds for the block & bottom end & it works out at £390ish including fully lightend & balanced, what i'm asking for ins'nt to far from the mini7 spec bottom end he supplies so i think its not a bad deal, he recommended a turbo cover & bonded plate, verniour duplex timing set, mg metro cam, is this sounding the right sort of ballpark cheers guys

SKYLINES ARE LIKE CLITS, EVERY FLANGE SEEMS TO HAVE ONE: see this sticker on my silvia

the Search-section on this forum is blummin superb & simple to use, unlike some other forums, without the search-section & the help of this bunch of chaps on here i'll never be able to !!!Start the day with a 998cc turbo!!! :) i'm getting closer though!

Tom Fenton says: I have it all, make me an offer

Sounds OK to me

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

brilliant!!!! cheers for your help & adivce all who have, i think i'm pretty much ok on my spec & i'll get my parts machined, & start the build, i'll include photos in the 'show me yours thread & probobly bug you all with little probs along the way

i dont really want to start a fresh thread, so could i have some advice on what to do with my dizzy, do i stickwith the 998 one i have, what settings should i start with, any recommendations for cam timing?

i'm really excited now! hopefully give this some stick at avon nxt year hehe!

SKYLINES ARE LIKE CLITS, EVERY FLANGE SEEMS TO HAVE ONE: see this sticker on my silvia

the Search-section on this forum is blummin superb & simple to use, unlike some other forums, without the search-section & the help of this bunch of chaps on here i'll never be able to !!!Start the day with a 998cc turbo!!! :) i'm getting closer though!

Tom Fenton says: I have it all, make me an offer

Our mg cam is timed at 110 deg which seems to work fine. Power past 7k. Tghis seems to be the limit of the 20773 pistons though, so get the megas, that's what I'm tryinmg next.

As for the dizzy, chuck it ibn the bin and get some mapped ignition.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

have you got the 295 head already?

if so, check the combustion chamber cc as they are reknown for being skimmed, and also give the valve seats a good checking over, they are prone for that too...


good luck and keep us updated :)

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

joeybaby83 i have got my 295 head stripped and ready for machining, it looks in really good condition, the only bit that looks iffy is where the heater valve go's on the head but i think it'll be ok, (there are pics in the 'show me yours' of my build)

when checking the cc's of the head chambers could i do this myself with a pepete & oil, i.e: is cc a simular measuremant to mls,

cheers will i think i'll be goiing the mg metty cam route, i'll have to check out these mega pistons!!!

also am i right in thinking that if using a 295 head that has been skimmed to compensate 'CR-wise' you could use dished pistons or is my thinking well off!!!

will a recon gearbox be ok or should i uprate anything?

Edited by clubminiflip on 14th Sep, 2006.

SKYLINES ARE LIKE CLITS, EVERY FLANGE SEEMS TO HAVE ONE: see this sticker on my silvia

the Search-section on this forum is blummin superb & simple to use, unlike some other forums, without the search-section & the help of this bunch of chaps on here i'll never be able to !!!Start the day with a 998cc turbo!!! :) i'm getting closer though!

Tom Fenton says: I have it all, make me an offer

yeah, cc's = cubic centimeters

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

so i can check this myself, i know a pepete & oild is cheaper than a machine shop price to check it! do the pepetes come with cc's as the main measurement if so where can i get one :oP i feel all warm inside hehe!

SKYLINES ARE LIKE CLITS, EVERY FLANGE SEEMS TO HAVE ONE: see this sticker on my silvia

the Search-section on this forum is blummin superb & simple to use, unlike some other forums, without the search-section & the help of this bunch of chaps on here i'll never be able to !!!Start the day with a 998cc turbo!!! :) i'm getting closer though!

Tom Fenton says: I have it all, make me an offer

oh yeah! i presume i use the metty turbo carb, are rebuild kits availible for these carbs

i was just reading the threads on the undercrown cooling jets! i'm mulling over this, it seems a good mod thats cheap enough if the motor is apart hmmm i'm tempted

SKYLINES ARE LIKE CLITS, EVERY FLANGE SEEMS TO HAVE ONE: see this sticker on my silvia

the Search-section on this forum is blummin superb & simple to use, unlike some other forums, without the search-section & the help of this bunch of chaps on here i'll never be able to !!!Start the day with a 998cc turbo!!! :) i'm getting closer though!

Tom Fenton says: I have it all, make me an offer

hi a friend has some AE 22463 pistons, +0.020" oversize,

size 2.5420" - 64.597mm

are these a suitable piston for my 998 turbo project motor, cheers guys, they are flat top pistons

SKYLINES ARE LIKE CLITS, EVERY FLANGE SEEMS TO HAVE ONE: see this sticker on my silvia

the Search-section on this forum is blummin superb & simple to use, unlike some other forums, without the search-section & the help of this bunch of chaps on here i'll never be able to !!!Start the day with a 998cc turbo!!! :) i'm getting closer though!

Tom Fenton says: I have it all, make me an offer

I've had a good look arouns and I can't find what pistons these are.

I personally think most available pistons will be ok up to 10psi. Assuming that everything is setup right (fueling, ignition etc.).

There's not much data for 998 pistons. The 20773s I've used worked ok upto 20psi, but once I increased the rev limit they're not so good.

Wil

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

They are standard late model 998 A+ flat top slipper pistons.

http://www.minispares.com/Product.aspx?pid=37841

As Wil said - possibly OK to 10psi.

Edited by Paul S on 23rd Nov, 2006.

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."

In which case I suggest a maximum of 10psi. Mine fell apart at 15.

But we are planning on using these pistons on some roadgoing 998s runing max. 10psi.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk