gsi bottom end

[benthehash]

I'm doing an engine re-build on my gsi lump.

when finished will run;

t40's
cam and pully
loads of head work including over sized valves
L&B flywheel
4 branch

i'm wondering what to do with the bottom end.
i'm thinking of high compression pistons, arp bolts and shot peened con rods.

any 1 done such work or any ideas?
thanks

[Nick]

Well mine is just about to go in for a full bottom end rebuild.

It depends what you really want to use the car for. All this "lightening and balancing" is a bit of f**** in my eyes, if you intend to use the car on a track, revving around 7k alot, you need to make sure that basically everything spins balanced, also that there's not much wear in the bearing shells e.t.c So yes you need to make sure the crankshaft and flywheel are balanced and maybe lightened slightly. Also shotpeening the rods gives them a little extra strength, but the rods are pretty good and should last with any sort of power your put through them in a t40 lump

if you plan to use it on the road as a daily driver, the L&B wont give you anymore Horsepower,it just reduces rotational mass. Substantially lightened flywheels can lead to suffering on inclines, due to the decreased momentum it's able to carry (i think that's right ?)

basically, on a road engine, just get the block checked over, maybe replace the rings and big end bearings, set of ARP rod bolts. Then do some light headwork and camshaft.

If your lookig for something to race, or use ona track, go for the whole shebang.

At the end of the day, alll that money on the road isn't going to make a significant difference. You get most gains out of a camshaft. But on a 1/4 mile, the more headwork, or the L&Bing is going to give you that slight
edge over a competitor !

Maybe a bit of a long and lengthy post, but there's no point spending tons of money on stuff that isn't needed for an everyday application

[Nick]

And i can vouch for the fact that an E16SE on T40's and a kent cam is really really great fun.

The only reason i'm doing the whole lot is because i'm gonna start using it more as a track car, but then it sets a ball rolling i.e fully L&B bottom end, so i may as well fork out for Solid lifters and cam to suit e.t.c

But at the end of the day, if it's what you want then go for it ! I'l be able to say exactly what i'm doing on mine. but the kinda General idea you've got. And some other more technical people like stu or dan e.t.c will beable to give you some better advice (probably)

[benthehash]

who are you getting to rebuild your bottom end? and what you getting done?

think i'm just going to put new gm piston rings in and bearings.
i's it worth sending it away to rebore the block for the piston rings?

im getting b+ head from blydenstein piper cam kit, pully, twin 40s

more info the better

thanks nick

[Dan]

when i built my engine i had autosprint in birmingham do my bottom end, i had actually took mine to 112k miles from 58k so i knew it had mucho abuse and needed a proper tidy. if you are going for a l/b flywheel then just aswell get the lot done imo. no major gains to be had but might help it rev abit better. I had the block decked on mine, and due to condition i went for a rebore

head and cam are the main choices which you seem to have sewn up, either the kent ast2 cam which i opted for or the piper 300 which jim uses are v good cams and deliver the goods.

twin 40's are a must as you have already decided, the key here is to find someone you trust to tune them and get the best from the car. there are alot of 'tuners' around and there are fewer good tuners. with finding someone decent you will find the carbs will be very reliable and offer decent fuel economy considering what the spec will be rather than going out of tune every other week and guzzling like no tomorrow.

After this as i have said in a previous thread gearing will make the car come alive. the standard f13cr cluster is ample, but changing the final drive from 3.74 to 4.18 will make the driving experience complete imo. it can be found generally in the 1.3 sr f10 box but others have sourced them from other places also as vaux chopped and changed their minds like the weather

[Adam]

I think some early 1L had a 4.18 FD too.

[mikey14sr]

The block will just need a good clean out, new bearings are a good idea, just standard size should be ok if the crank journals aren't too worn. You should be able to get away with just honing the bores and fitting new standard size rings, again, thats if the bores werent excessively worn in the first place. A set of stronger rod bolts and idealy new main bearing bolts should help stop it flying apart at high revs. A quick re-build of the oil pump is a good idea too.
All of this is basically covered in the haynes manual, just follow what it says in there if you have the tools, time and ability to do it all yourself, or try to find a local engine builder.

[benthehash]

the bores are in very good condition, and some light honing was recomended.

dan when you said got your block decked do you mean skimed?
if so how much by and whats the advantage?

im buying a new box from a company called T2 its got 4.53 final drive and LSD

[Stuart]

how much are you paying for the box and FD.. please DONT let it be those con artists on ebay in wales

[Dan]

basically yeh the block was skimmed, this can aid a better compression ratio for the engine, as regards the fine details i'm afraid they escape me now as its been over 5 yrs since i had it done lol

I also back stuart up fully, i to hope you havent paid alot of money for what is effectively a bog standard box with a diff that could be built for half the cost to the same end result.

[benthehash]

yeah it was ganna be from them but not now.
looks like i'm gana be ripping my spear box apart but saving loads of money!

where's the best/cheapest place to buy
arp main bearing bolts/rod bolts
and
gm (or better)?
pisten rings
bottom end bearing

[Stuart]

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=8033229526&ssPageName=STRK:MEWA:IT those theiving bastids!

the price DOSENT include the diff..... good job we saved you lol If it did include the diff then its nearly worth it.

[garyc]

Try http://www.allittmotorsport.co.uk/ for bearings and rings etc. I doubt you will find anywhere cheaper.

As for decking the block, you need to measure how much the top of the piston is to the top of the block. You will need to use a dial guage for this. Whoever does it will then be able to skim the block accordingly.