QTB

As the time nears to actually cranking over my engine for the first time I keep raising questions in this confused little head of mine. So I thought I'd see what the masses say

1. My bottom end has stock LS2 components with ~27k miles, but I have replaced the cam, timing chain, heads, lifters, rockers, retainer and locks. All put together will assembly lube. Do I need to use a break-in oil on the first start up? Regardless, I'm going to get it up to temp and do a full oil change.

2. I'm thinking of converting to SD from the stock MAF system, for several reasons but would it be to my benifit to do the initial starup with the MAF in place to get a sort of base assessment on the tune? I'm still looking into all the details needed but I'm using HP tuners and they appear to fully support this.

3. With the replacement of my top end I've decided to go away from the hydraulic cam and switch to a solid roller cam. I've set the initial rocker arm clearances to 0.015-0.016", per Ed Curtis. My cam sheet calls out 0.018" HOT. For reference I'm using Jesel sportman shaft rockers for L92 heads. What are people running that are using a SR cam?

4. I don't know yet but I'll fill this in at some point.

Thanks in advance!

QTB

I thought of #4

It looks like SD should use the MAP, and a IAT sensor in conjunction with a good WB O2 sensor (Currently using AEM). Where are people putting the IAT? I believe it's part of the MAF in OEM form.

QTB

Bueller?

S10xGN

iTrader: (11)

Nice build! Sorry, I have no experience with solid rollers or EFI. Not many here running a solid cam, you might ask in the "PCM Diagnostics & Tuning" section about the SD setup...

QTB

Thanks! I guess I'll do like the rest of this build and wing it, fail, try again.

COPO9560

Solid roller cam does not seem like a good match for stock bottom end. Solid roller advantage is higher rpm - something your stock bottom end will not support for very long.

Solid roller, Jessel shaft rockers etc are big $$ parts. Why would you put these on top of cast pistons, powder metal rods and cast crank??

QTB

Initially I'll have the rev limiter @ 7k which the stock bottom end is capable of holding I believe. After tuning it may move as high as 7200rpms. Which yes the valvetrain is overkill, I agree. But eventually the bottom end will get replaced and the rev limiter will move further north.

The other reason for the high rpm goods is it's primarily a weekend road racer and I wanted a top end that will hold 4-7k for 20min sessions and all the power at the upper end of the power band. I know every muscle car guy in here will flame me but I can honestly care less if I lose low end torque and power below 4k. If anything it will keep me from spinning up the tires out of corners.

Now do you want to contribute anything useful or just critique the rest of my budget?

COPO9560

Useful contribution:

Your short block is all stock and was not disassembled, no need for break in oil. On subject of oil, are you planning to restrict flow to heads? Stock or modified oil pan to control oil in turns? Pump replaced or shimmed?

My experience with solid roller cams & Jessel is limited to BBC but make sure you double check stand height and geometry. Valve spring life on solid rollers is poor so keep an eye on these every time you have to set lash. Solid rollers don't need adjustment as often as solid flat tappet but definately not set and forget like hydraulic. Checking hot is not a lot of fun, on LS with coils on valve covers will be a pain. Old trick is to get a few set while hot (both sides, intake & exhaust) and let engine cool down. Check these when cold, record the value and reset the others. Running slightly tighter lash can produce a little more power but this is risky.

Solid rollers are an issue for BBC street cars - life very short even for the "street" versions. At low engine speeds, oil flow to lifters is inadequate and rollers end up failing - then dump their needles into your rotating assembly. Lesson here is to minimize idle time.


Assume you upgraded pushrods too as stockers will likely bend at speed with springs you will need to control the valves. Lighter valves help alot at high engine speeds, not sure what you have as you didn't mention what kind of head you installed.


Older LS1's had some potential rod bolts when pushed, not sure about LS2. A set of ARP bolts is cheap insurance.

Good luck and hopefully it will hold together.

QTB

I have an 8 qt pan with trap doors and baffleing. It will hold 9 qts when I install the oil cooler. I'm looking into the Melling HV pump, but haven't purchased anything yet. Per your comment below about low oil flow to the lifter at low rpms this leads me to believe I should consider the high pressure version. I've also drilled a 3/8" hole in each of the lifter trays to help oil return.

I was a little curious about setting lash while hot, I think I'll try using your tip and see how things work. Depending on how good the tolerances are I see some potential issues but I guess it will depend on how sensitive the engine is to slight amount of lash variation.

Good to know, I learned something

I'm using FTI 3 pc heavy wall push rods and the heads are un-ported, un-milled L92 heads.

I appreciate the feedback. I hope it holds together too, until I figure out which route to go on the bottom end.