Work begins

[peter b]

Keep us posted. Out of Interest what tyres are you running on the omega rim. They are only 17x7

16X8 i think from memory.

[etrocket]

what tyre you put on it??

[peter b]

Mickey Thomson street slicks but they only for the drags when I get it back on the road will go and have a crack.
At the moment has std SSV rims on it.
Oh and another change the APC exhaust came off I cracked the poos got sick of being too loud and a few other fitment issues. Car now sports a full di fillipo 3 inch exhaust with 17/8 headers. Loving the note but still have to get around to putting tips on

[peter b]

Bit of an update ran car on the dyno for first time since the cam install as had fitted 4.11:1 gears after shorter gears will show less power on dyno. Car showed 320rwkw but did not sound healthy at higher rpm now when raced at the track always felt the car fall over but was leaning towards being too short a gear ratio however being able to be outside the car whilst at high revs it became apparent that was not my issue.
I was already set on pulling heads off to deck them 40 thou and install street series tie bar lifters. Whilst heads were off gave me a good opportunity to test the springs (has been on the to do list for a while but never had time) well upon removal of the spring the retainer and base showed signs of valve float. Checked two springs and they had dropped from 155lb @ 1.810 to 116 lb @ 1.810. There are a few factors that come into play as to why the springs dropped that much pressure, Heavy valvetrain I was running a steel retainer which probably didnt help, Cam ramp rate too aggressive for rate of the springs (more likely). So the decision was made to change to a diff set of springs, bases, titanium retainers and new seals of course. This time shimmed up the springs to have 185lb @ 1.820 408-416 lb @ 0.625 lift this may seem too heavy for a hydraulic roller but with a genuine LS head you are restricted to running a 1.3 OD spring which is one of the downfalls of the genuine heads. The camshaft is quite aggressive and thus needs valvetrain to be able to absorb the effects of the camshaft without suffering from valvefloat. Harmonics is a big thing with LS engines and if the valve spring pocket was larger would be able to fit a larger OD spring and make it easier to keep the valvetrain stable.
Due to seat pressure I changed from the street series Morel lifters to the Race series lifters.
Sat heads on checked piston to valve and had no clearance without head gasket and minimal with gasket so the nightmare of a task to flycut pistons began. This was done with engine still in the car and is a very mundane task. Cover top of engine with tape, Turn engine over so piston is at its uppermost position (L98's the piston protrudes the bore by 8 thou) Install cutter into head and fit head with 2 bolts, Set up cutter it has a stopper so basically set how deep you want to go do this 16 times and clean up everything. On went 40 thou compressed cometic head gaskets, decked heads, new arp head bolts. Set up with 1/4 turn preload engine fired straight away and before being retuned showed a significant improvement down low more responsive and wants to pull in every gear. Car has been retuned and currently makes 343rwkw 809nm roller torque (for those that dont understand and read a lot into numbers, dyno can read torque 2 ways, reading what the car is actually putting to the rollers i.e roller torque, or with correction taking into account diff gears as having 4.11's does increase the number)
Has shown a remarkable improvement in torque and is a lot more fun to drive and turns tyres in 2nd gear on the roll snapping straight up to 7100rpm in doing so. Previously car would fall over aroung 6500-6600 rpm mark but is now holding right up to 7000rpm
For those that have L98's I highly recommend decking heads the extra comp gives back low and mid range which you lose when fitting the camshaft
Stock they have a 70cc chamber and around 10.2:1 comp. 40 thou off gave me a chamber size of 63.2cc and combined with the thinner head gaskets gave me a compression ratio of 11.5:1.
Makes them really come alive.

[peter b]

[jaykay]

Nice pic..whatever it is of peter

[peter b]

Hmm not workin will try later

[peter b]

small update and is a sad sad death to the 4.11 gears oooh poor pinion who has no teeth left oopsss
and before anyone says i wasnt doing burnouts at the time but these things will happen time for new gears and try again

[qwigybo]

should've been doing burnouts and it probably would've lived :P lol

[Tryhard]

Treat em mean keep em keen

[peter b]

there were plenty of burnouts before hand gotta warm up the ets somehow....

[BEARWOOD]

Going with 4.11 again?

[peter b]

Yeah I was happy enough with how it was with 4.11's and know what the car does my other option being 3.7's wouldnt be a massive difference and can get the 4.11's cheap enough.

[dogsballs]

did they have the snout on the pinion gear?

[peter b]

did they have the snout on the pinion gear?

Trying to picture what your meaning as the pinion is one piece goes through the diff and has the coupling which is splined and goes over the splined end of the pinion. The coupling bolts to tailshaft. The bearing that the pinion goes through is now locked up but could be due to metal going through the bearing but as far as any kind of snout I am very much unsure as only split the case and pulled the centre out.
I will see if I can upload some pics soon as a pic shows a thousand words.
I always steered clear of building diffs and plus hate the smell of diff oil once you get it on yourself you smell like it for days.