31 replies to this topic

[Reece Jackson]

hi there everyone i have recently took delivery of another new ultra high spec 998 cc unit to go in my autograss race car current engine spec to be improved is as follows
998 a series block bored to 1046cc pocketed decked
+60 slipper pistons
lightened balanced wedged crossdrilled crankshaft and rods
centre main strap
arp bolts
kent 310 camshaft
fully adjustable duplex timing gear
full slarky 940 head 37.5x31 plasma nitrated valves skimmed by 120 thou
1.27.1 rockers
lightened followers
megajolt v3 mappaple ignition
ultralight billet flywheel and backplate
sintered paddle clutch
45 dcoe webber 38mm chokes
7.5" manifold
large bore lcb manifold
0.9456 sc drop gears 24/23
engine pushes out just over 100hp at the fly wheel and around 87-90 atw at 8'500 rpm with about 85-90 lb/ft of torque
pictures will be added shortly

[Reece Jackson]

pictures as follows

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[Reece Jackson]

my car weighs around 430kg with fully adjustable rose joint rear arms etc etc.

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[liirge]

JUST WOW!!!
that's a lovely specification you have there. What kind of Compression ratio you got?
What's the advantage of the paddle clutch is it a race specific thing?
Any reason why you didn't go for Roller rockers?
You sill using the mechanical pump, and what kind of breather system are you using?
Sorry about so many questions i just love spec'ed Small bores.

Edited by liirge, 15 November 2009 - 06:12 PM.

[Reece Jackson]

hiya mate the compression ratio is as high as possible so about 13:1 i run a facet red top pump i didnt go for rollers as in my eyes there is no advantage of roller rockers im sure many people will disagre but i think the old type split rockers are just a good as regarding the breather system i run every breather possible eg.custom breather on rocker cover custom tappet cover breather and 1275 flywheel housing with breather also i run a paddle clutch because i need to set off as quickly as possible on dirt cheers

Edited by Reece Jackson, 15 November 2009 - 06:35 PM.

[Reece Jackson]

head will be fitted tomorow im just in the process of searching for a set of straight cut gearsanyone have any for sale

[Reece Jackson]

hi again everyone i was just wondering if anyone has ever done a 998 to a similar spec to mine cheers

[liirge]

yer i have kind of....
not quite as wild cam, but double your overbore.
everything lightened balanced, 12g940 head, twin HS4's, Megajolt. look at my build thread in my signature
Thank you for your answers, previously,
its amazing how many people don't increase the amount of breathers on a 998 when they up the power, they only didn't put 2 on the 998 as a cost cutting exercise.

Edited by liirge, 17 November 2009 - 01:23 AM.

[Reece Jackson]

tell me about it mate revving as hard as mine does it eould blow it's self in bits without all the breathers ive used

[9FDXEH4]

hi again everyone i was just wondering if anyone has ever done a 998 to a similar spec to mine cheers

Hi there!

Small bore power mate!i have an engine spec similar to yours.

take a look
http://www.theminifo...x...06914&st=30


cheers

[Reece Jackson]

nice engine mate i have just got off the phone to bill richards who is helping a bit with my engine and he tells me that he once built an engine to the same spec as mine that was running 118hp so i was maybe a bit low with my estimate bering in mind my engine spec is still well in the development stages i plan to go to 40mm chokes instead of 38mm which will up the power even more
and i dont run an alternator or fan which takes a lot of drag off the engine and gives good power gains not
i love small bore motors any more specs!!

[Reece Jackson]

just fitted the cylinder head and rockers back on to the engine and blooming eck a kent 310 cam doesn't half have some valve lift the rockers are always tight with tappets fully slackened off !!

[Reece Jackson]

hi there here are some pics of the cylinder head fitted this is with a very slight rocker pedestal spacer does this amount of lift look normal any help would be greatly aprreciated cheers reece

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[liirge]

is there any reason why you didn't stick roller rockers on here...
how much thread left on the adjuster of number 1 exhaust and number 2 inlet?
are they all gapped?

Edited by liirge, 22 November 2009 - 12:25 PM.

[benpopham]

Hey... Love these small bore topics... Iv posted my spec up before, will keep an eye on this one