steve40th

Noland, they were installed by the machine shop. I did the intake portion of the head too. They were called time certs, and supposedly allot of motorcycle people do these do, and are stronger than standard helicoils.

BlackHarleyMan

Thanks Steve, I'll check into them.

rklessdriver

External Balance engines... All that means is that the crankshaft counterweights do not have enough mass to balance out the weight of the rods and pistons so the factory put a counterweight (external mass) on the flywheel and/or harmonic balancer.

Internal Balance engines... means that the crankshafts counterweights have enough mass without utilizing external weight.

One way or the other it dosen't matter. Both ways balance the roating mass out. At 500hp and 6500RPM thre is no advantage or dis-advantage to either performance wise. Since LTX's orginally came external on the FW and neutral on the blancer, if it is feasible I intend to keep Nolands engine balanced this way. Should he need a new flywheel, he dosen't need to do anything special. Should he want to convert back to a dual Mass FW all he has to do is buy a new one (Ever seen a neutral DM FW?? Want to be the one to grind that weight off it everytime you need a new FW??). Convert to an auto trans, all he has to do is go down to the Auto Zone and buy a stock Flex Plate. It's just easier.

BTW, if you don't use header gaskets, all that leverage hanging off your headers (your exhaust system), won't crush them and you won't need to re tq the bolts.
Will

96lt4c4

I did



But this was because I bought an already internal balanced rotating assembly. If mine goes out I am going with a single mass.

MTVette

Hey, Noland. I just got back from a fun day at the track. No, I'm no longer running the HotCam. I updated my profile page for clarification. The cam is a custom grind, based on the cylinder head flow numbers. The criterion for the grind was to restrain the exhaust flow so as to permit the car to pass emissions inspections. The injectors are 30#, and the tune was done by SloRVette. This was his first shot at the tune, done without a dyno. Next week he'll finish the tuning for partial throttle.

At the track today, in 95* weather with a baro of 29.71, the car was consistently running 12.02 - 12.06 times. I made it into the third round of mod class, before giving up a -0.002 second red light.

Mike

BlackHarleyMan

Very nice Mike!.......Times seem to be rock solid even in the heat! Here's a few questions for you, why did you choose 30lb injectors for your motor? Was that what was recommended with the build or what? When Will told me what he expected my HP level at the crank to be on this motor, I called Jon (FCInjectors) and talked to him about what size I should get. He explained to me that the size injector was based off of the expected motor's HP output, and informed me that I needed 42's for my build. I then marched my happy butt off and bought a set of Jolly Green Giants. When I spoke to Will about his he informed me that he uses a smaller injector for his monster motor (600+chp) and his injectors see less than 80% duty cycle. Now i'm in a daze and wondering if I over achevied or if I made the right choice. The science behind these 383's and injector sizes seems to be "Smoke and Mirrors" to me at this point. Thanks for the update and hopefully you'll drive that beast down to Carlisle this year, we can get together, run down the streets and scare the Natives!......LOL

Noland

BlackHarleyMan

I think Rob (BlueWasp) did this as well. Maybe he'll pipe in and clarify.

Noland

STL94LT1

Sometimes it seems if you talk to five different tuners on injector recommendations, you may get five different answers. I'm sure Jon won't lead you wrong.

My LPE Twin Turbo is putting out 650 HP, and is running the SVO 42's. But the C5's fuel pressure (58 psi) is much higher than our C4's.

BlackHarleyMan

I totally agree with THAT statement, I trust Jon 100% and just as an insurance policy on it all. I bought an AFPR and got the Walbro GSS307 255gph Racetronicx fuel pump to feed this puppy. Hopefully that'll be enough insurance to make my tune achievable with the 42lb'ers without too much of a headache for Ed.

Noland

BlackHarleyMan

Will,
Are you recommeding to install the headers with-OUT gaskets? Or am I sniffing too much of these residual brake cleaner fumes? PLEASE explain that one.

Noland

Bluewasp

My 383 is internally balance using a GM dual mass. The dual mass was balanced to zero first...

Bluewasp

I'm using 30lb injectors with my 847 383 setup.

42lb sound a little big but i could be wrong.

BlackHarleyMan

I appreciate you confirming that one. I thought you told me that it was a Internally balanced motor with a neutrally balanced Dual Mass.

Oh-Kay!...........Another 383 with 30's.........What's your CHP/RWHP on your Motor Rob?

Noland

LT4POWR

I'm running 42lb injectors on my stock bottom-end 350ci LT4....don't worry about it...it's all in the tune...mine idles and runs great. Also, imo, I don't see the need for an AFPR, just get a good dyno/street tune.

BlackHarleyMan

OK, JUST to let YOU know..........Alot of the research on this build came from your combo!...........You send me the specs on your engine awhile back and I've used it as a template for this setup! SO, Thanks to you, here I sit BROKE AS A JOKE!.......Thanks!

Noland

P.S. I would love to see your dyno sheet if you have one for your motor. When I saw your combo, I knew that if a stock bottom LT4 could make that type of power and be driven daily, then a stroker would kick Azz!

N

MTVette

Noland, I'm not enough of an engine guru to give you an informed answer. My builder said he wanted to go with 30# injectors, so I did and I'm happy with the result.

BlackHarleyMan

OK, Thanks..............I just wanted to know how you got there. So the builder spec'd them out.

R/Noland

JimiHendrix

Can you describe the performance difference between the 350 and 383....via seat of the pants description. Is it a drastic difference?

BlackHarleyMan

Now THIS, is going to be GOOD!

Noland <- Sitting back eating Popcorn!

MTVette

My experience covers much more than just increasing the displacement. In addition to the work on the rotating assembly (0.030" overbore on the cylinders and a 3.75" crankshaft), major work was done on the intake to increase airflow. The LT1 cylinder heads were ported, so that the intake flow increased from the stock 210 CFM to 272 CFM (cu. ft. per minute) at max valve lift. The stock intake was also ported, and the 48mm throttle body was replaced by a 58mm body. To keep up with the increased airflow, the standard 22#/hr injectors were replaced with 30#/hr. The exhaust work had already been done - long tube headers, high-flow cats, and an X-pipe.

All engine builds have to be done as part of a plan. Increase just one component and the results will be disappointing, because some other part of the engine now becomes limiting. For instance, when I installed the HotCam without any changes to the intake or exhaust, my best time on the quarter increased my a measly 0.05 seconds! Then, when I changed out the exhaust, I got a full three tenths off the quarter, and the intake became the limiting factor.

Finally, to answer how the change feels, it is now scary fast. Estimated 0-60 time is about 3.4 seconds, and the 0 to 100 time is about 8.5 seconds. When I hit the gas while cruising at 30 MPH with traction control off,, the back end skitters back and forth as the car leaps forward with a screaming roar. In the quarter mile, I took almost a full second off my previous best, and increased my trap speed by 10 mph.