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iTrader: (2)

After losing my clutch back in July .I decided I would go ahead and rebuild my engine.i just got my block back and new CCW crankshaft (1729 grams)
my question is the last crankshaft my clearances were between.0024 and.0025 on the mains and the bearings were perfect.
I will be running a 150 shot of nitrous, will I need to tighten them up or leave as is.
(Coated king bearings)
one more? After having lifter issues (2 years ago)and damaging one lobe on my mike jones cam.
he’s doing a regrind for me.
The cam I’m running right now is a Cam Motion llsr 255/269 114+4.5 @703/683lift
mike is regrinding the cam to 261/268 115 @683/689 lift
my question to you guys .do you think I will gain hp changing back to the mike jones cam .if so how much difference in hp.
any idea the car is making 650rwhp right now.I’m thinking very little if any
450 cid engine with ls7 415 cfm@700 lift cylinder heads

IGN-1A

Hi Rod, OK.
What I do for a Laugh GAS Rod IS to GRIND a GROOVE in the top half of the Conn Rod.
Where they "kiss" AND at the crank side.
This will allow OIL to Squirt into the crown of the piston.
Lance

jayyyw

The Mike Jones cam will make more power. With 450ci, I'd go with that, if not bigger. All depends on your end goal, really.

Vega Racer

Please explain more. And a picture please.

Che70velle

iTrader: (6)

The nitrous shot will affect the rod bearing load, not the mains load. Leave the mains at .0025
I would go .0025 on the rods if the N2o is an occasional toy. If your gonna spray a lot, consider going .0028 on the rods.
Rule of thumb is always set up bearings for intended power level and RPM. More power OR more RPM will need more hydraulic wedge (cushion) in clearance (bigger). Of course your oil pump must be up to the task of handling the added clearance…flow trumps pressure here. Volume lubricates the engine, not pressure. Pressure is just an indicator of the health of the oil circuitry. I’m NOT a trying to turn this into an oil pump discussion. Just explaining why you’d want to go a tad bigger with clearances and not tighter as you were asking.
As far as the cam question, I feel like the lower lift numbers of the new cam could hurt a tad, as lift always adds the potential for torque. Your heads being rated at .700 lift is an indicator that you’ll want to push past that threshold for a few degrees of duration. The phenomenon is referred to as Flow Dwell Time. If you have a port that flows peak at .700 lift, push past it by .020 for a few degrees of duration, in order to take full advantage of that flow potential at that .700 lift. Just a tip for maximizing torque, all things being equal. Basically your holding that valve open longer at that number to maximize the effort.
Mike is a smart guy and won’t steer you wrong, so it will be interesting to see how it turns out. The tighter split might help some to counteract the lift. I think we have all been putting too much split in our LS7 grinds, myself included.

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iTrader: (2)

Jayyyw he first spec it for 261/273 with 115 lsa @743 / 746 lift
it being a regrind and he decided he didn’t want take away of all hardness of the cam.
the original specs on the cam was 260/264 with 114 @643/645 lift (when I first had this cam spec I was running stock TFS 260x now ported by Greg Good)
it’s been laying in the garage for the last 2 years with the cost of these 8620 cam cores.
I was thinking it just stupid to leave the cam just laying around when it might be fixed.
I’m going thru the short block right now. I was thinking maybe I can pick up a few more hp.(this all started when I lost my clutch last month the snowball affect)I ordered a monster triple clutch with aluminum flywheel it’s been 2 months maybe next week.
hopefully I can get everything back together and get to track in October and get that 9s run.just dreaming

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iTrader: (2)

Che70velle thanks for the feedback on bearings clearance.
I’m not second guessing mike I’m thinking lower lift and better spring longevity for the street.just guessing
I’m using a max 5 controller set up for a 150 progressive shot on a 102 plate system
if I ever decide to go to a bigger shot .I’ll go direct port just saying

Fishmasterdan

Reduced bearing clearance helps spread out the load over a wider area.. This is a second theory on the oil wedge.
I ran between 200 to 300 shot for several years on a .00017 rod to crank.. No noticable bearing issues when refreshsed.
Another motor I ran .00027 to 30 and it egg shaped the rods over time running juice.

Che70velle

iTrader: (6)

I think you put toooo many zeros in front of those numbers…

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iTrader: (2)

Well it’s back to the machine shop for me today(2hour drive).started checking
my cylinder bores this weekend and they vary from.0032 to .0040 with about 5 of them
under .0035 and I asked them to hone them to.0040(it was 4.166 bore )their no way in hell that I’m going to put a 2618 piston in a .0032 bore.(4.170 bore) and me shooting a 150 shot of nitrous .at that clearance I wouldn’t run them NA.(I keep measuring them hoping they would grow)trying to make them work.
l was just thinking ,I wonder how many guys have assembled their engine and due to bad machining . They lost their engine and go to back to the shop and they tell you it was a part failure.
a engine builder is only as good as his machinist

IGN-1A

Hi Last1, I would ask your machinist to Mill a "flat" of 1/400000000 " wide on each side of the ConnRod at the rod
side where the bearing lives. Then clock as CHEV70 stated, this WILL ADD OIl FLOW (cooler oil) to the rod bearing where it is needed AND act as an Oil Jet to COOL the piston crown.
Lance

Last 1

iTrader: (2)

ING-1A it would nice if you would post pictures of the rod mod ,for people that’s not familiar with it.to let people see what your doing.
my block is setup for oil squirters as far as for the pistons
the machine shop correct my block today,not the first sorry that we missed machine your block .anybody can make a mistake but it would’ve be nice to hear were sorry about it.
I’m hoping I can get the car up 680 rwhp from 650rwph with this new short block.
@ 72 I’m starting to lose a little fire working on this car.i should be up and running by October so I can get back to the track for test and tune.

Che70velle

iTrader: (6)

Spot on here. And I’ll add to this…A machinist is only as good as his MACHINE. I realize that not everyone out there has access to a shop locally…or semi-locally…that utilizes CNC equipment. Living in the southeast has its advantages in this manner. Don’t have to drive very far to find a shop with CNC equipment that is ***** on accurate and the user has the gullibility to know how to measure out to .00001
My latest build required me having to change machine shops. My previous guy worked for Joe Gibbs and was good. Like real good. But retirement was on his radar and I’m happy for him. Now with the help of a few friends, I was able to get in with Ernie Elliott which is only 7 miles from me, but his doors have always been closed to the public. I measure everything. EVERYTHING. And this machine work is the most accurate I’ve seen in a long time out to .0001
I told him I’d bring him all my stuff if he didn’t mind, and he is on board. Of course Ernie is retired from the big stage of Cup stuff, but he’s still involved in vintage racing classes (80’s-90’s) of older Cup cars on road courses primarily. The guy is good, but when every station in his air conditioned shop is computer operated, it makes him simply look that much better. I couldn’t be happier.

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iTrader: (2)

With most of these machine shop they just want to get it out the door.it’s just a job to them.(but this is your baby)
most of the employees are just waiting on 5 o’clock
it’s pretty sad that they don’t care .
want I’ve found out over the years ,that a lot of people go to work but don’t come to work
after working 44 half years in a underground coal mines.
but when they hired me they knowed what they were getting with me /from the neck down.
we all can’t be doctors ,but I did raise one
sorry about ranting on.it’s pretty sad that most people can’t work without having a phone in their hand this day and time.
Che70velle that’s one bad a?? Chevelle /Scott you would’ve been right at home @ LSX fest yesterday

Che70velle

iTrader: (6)

Hope to make it one year. I’m a busy boy!!

grinder11

iTrader: (1)

Last 1, you need to find a good machine shop. Believe it, or not, there are a lot of guys out there that do take a lot of pride in their work. I'm a retired T&D guy. But I was/am one. If I made a screw up, it ruined the next several hours of my day. I liked challenging jobs. There are good shops out there that have skilled workers who don't just watch the clock. Finding them is the hardest part....

Guy with a Chevy

Phones are the devil!!!

I was escorted through the GM north auto dealer in Corpus Christi , TX last week to look at the 80k engine they sourced to replace mine and took me to the bay of the tech that would be working on it. He was sitting on something short on the ground where I could see he was looking up parts. Just as an observation I saw behind him he had a comfy looking stool where 2 computers sat open and powered on and I just laughed it off inside my head for a sec because I see this everywhere. Sadly this is our adaptation of something that will never stop.

grinder11

iTrader: (1)

At least he was working, looking up parts!

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iTrader: (2)

yes there are good employees out there and people who care.and anybody can have a bad day
this shop has the best equipment in town.lots of CNC machines.
i keep asking myself why did they have to take a day off when my shi? was there.
they even nicked the crank were the rear seal runs albeit shouldn’t affect the rear seal
it being a billet CCW crankshaft I can tell you they don’t give them away
they were even so nice not to tell me about it.

jayyyw

My engine builder used to use a drill with a customized hone head attached to it to do all his blocks. He finally upgraded to a machine but its still a manual setup. His tolerances are in that .0001" range. Blows my mind what skilled people are able to achieve.