No we good and I agree with that mentality. It's just 1 part on my car that If breaks could be catastrophic. I built the rest of the car to handle about 900 wheel knowing I will most likely not even get above 650. So I'm continuing in that path by choosing the strongest k member possible. Which is the stocker, which we all know won't break. also if the after market were to break and all ended well, replacing it will be a headache

 

still open to ideas on oil pans if necessary...


but moving on to vacuum pumps. im almost certain that i will need one. ERL said in the paperwork that the stock PCV system wont work with a motor this size. also this is a gen 4 5.3 block and have read that these have terrible bay to bay breathing and a vacuum pump will help. also there is an assembly for sale in the classifieds so might pick that up.

question is, his pump is recommended for 1000 hp turbo builds.....what happens if i run that on this motor? according to what i have read i should use 10 AN fittings, the used pump is 12 AN, will that be a problem? it does come with a valve to help control how much its producing.

 

i currently have a mighty mouse can that i never used on my old setup. do you think that will be all i need?

 

Floorman,

Someone correct me if I'm wrong here - but from my understanding:

Running a vacuum pump will not hurt your engine in any way shape or form, unless you use excessive vacuum, which causes oil to be robbed from key parts of the engine.

I can tell you that the stock PCV system isn't enough even for a 427. I have more smoke from my single breather than I should.

One of the very near future additions to my front drive, will be a vacuum pump. I've done the research, and all things point to: Why don't I already have one?

The advantages out-weigh the risks, especially if you run low to moderate vacuum on an NA application. Blowby is a part of every engine - how minimal depends on numerous factors. One thing is for sure, a vacuum pump rids you of this.

 

Depending on the kit they do come with relief valve. 12 in about all you should run in a DD to prevent starving the wrist pins.

You can also control that with pulley size. If you size your pulleys to pull 12 in at 7500, then unless you rev past that you have nothing to fear.

It will somewhat tame your cam also fwiw.

 

the only issue here is his pump will probably eat more power. i found a site called GZ or something like that and they helped explain a lot. they also said you dont want run a larger pump unless you have too because it takes power to move the pump, so a smaller will eat less and a larger will likely not add any hp because my gains are being consumed by the pump. so yea its a good deal in the classifieds, but not for my build. what i will do is run this mighty mouse can which vents, and see if that gets me by. ill just make sure i buy an ATI balancer now that has the ac pulley attachment that way if in the future i do go vacuum, i wont have to touch the balancer.

 

I am doubtful you would actually lose any power from the pump. If anything, you stand to gain a pony or two. It takes power to turn the pump, but what it provides in return imho is more important than just some hp gains.

Don't look at this pump for potential hp gains or losses. Look at it for the advantages it provides..

 

correct but 9 times out of 10 you will gain a little bit of power running a pump is what i have found. so why run a bigger pump then necessary if it still eats 4-5 more? its n/a so im pinching ponies here

 

Right. No one is recommending you run an oversized pump. Just get the appropriate pulley, and you're good to go .

 

correct, thats what im saying, but the one im referring to in the classifieds is a large pump. large pump will still consume more power weather you put a small pulley on it than a smaller pump with a correctly sized pulley.

 

some questions about sensors, obviously for the most part i would want to run GM sensors, but even the new ones id buy at the dealer isn't REALLY GM. would it be better to run my 18 year old stuff like the knock sensors, cam/crank, oil level etc from my LS1? or should i just go buy the new stuff from the dealer?

water pump recommendations, electric isn't for me right now so stick with a standard belt driven......same question, re run my old ls1 pump? buy a reman from the parts store? new thermostat for sure, probably a fail safe from auto zone.

 

GZ sportsman will be perfect for you

 

yea thats the one i saw that i liked. im goona have to hold off the mighty mouse should do ok for now

 

bump, the heads are a week or 2 out so would like to start sourcing the little stuff. can i re run my ls1 knock sensor even tho its in the new locations? would you rerun the 18 year old crank sensor vs buying a new ac delco? basically any sensor would you trust the old oe quality one or the not so great but new ac telco

 

Buy new. It's not worth plugging in old stuff. This is an opportunity to renew as much as you can. Imho. For example, when I did my 427 swap, my oil pressure sender unit died. No joke. It was a pain to replace.

Also, knock sensors on the side (so you're working with a gen 4?) Are m8 1.25. your gen 3 sensors are m10. Won't fit. You can plug it in the secondary m10 on the side with an extension harness, but it's not a great spot and tuning them in to work properly can be tricky. So either drill/tap a m8 1.25, or don't run k sensors.

Edit:

I wanted to add, that people have made it work. But it was tricky. If you Google knock sensor from gen 3 to gen 4, you'll get a crap ton of people asking the same question. Some have different tricks. At the end, the best way for the sake of accuracy, you'll have to drill/tap. Someone more knowledgeable may know a trick to make it easier without drilling/tapping.theres really no "easy" way that I know of.

 

correct gen 4 5.3......so these motors only had 1 location correct? so were the gen 4 computers tuned to operate off the side like that where im assuming it runs a little different? so the gen 3 computers are looking for a different type of signal thats whee the tuning can come in? ill ask my tuner his opinion on this as well.

we can agree that the OE units are the best quality, and basically all acdelco is still basically a reproduction approved by gm, and its not possible to get a new OE piece correct? you would prefer to run the new ac?

 

Gen 4 blocks have a knock sensor on both sides. Driver, and passenger. The picture below explains the situation, because this is extremely common:



Correct, the gen 3 sensors were a 2 wire plug, the gen 4 sensors are a 3 wire plug (or 1 wire and 2 wire... that's irrelevant anyway). The Gen 3 PCM is not compatible with gen 4 knock sensors in any shape or form on a high level. Now, if you want to do the research, there are tricks people use with HPTuner, to make it work. The problem is two fold:

1) It's a lengthy process, or one that's lengthy because of all the googling
2) The accuracy achieved with this method is so far deemed *not* reliable.

Given those two factors, people just don't run a knock sensor unless:

1) You drill/tap both sides to accommodate the original LS1 (gen 3) knock sensors. Then, you're good to go and you will have properly working K Sensors.

As for the sensors: Yes. AC Delco are the closest you can get for sensors that are from factory. These will serve you well. *Keep* your original sensors in case your AC Delcos fail.

I think this will be a matter of opinion. Some will say use the old ones, and that's totally okay, too.

I am currently not running knock sensors on my 427 swap. As long as the air/fueling is dead on, and timing is properly tuned, this isn't really an issue. A GOOD tuner will be able to tell when you're knocking - and they'll back off the timing to get you to MBT (Maximum Torque Timing) without the onset of knock/detonation. The trick is finding that GOOD tuner.... ask me how I know.

Edit:

And yes, you're reading that correct. One of the alt. locations on the gen 4 block are an engine mount hole. Someone correct me if I'm wrong. My memory is failing. But, again, this is another reason why drilling/tapping will be your best route out of this.

Edit # 4,456:
I suck at getting all my helpful thoughts out on one go, BUT: *IF YOU plan on tuning this combo YOURSELF, TAKE the time to drill/tap knock sensors in!!* - I wish I did this.

 

awesome info i appreciate it.......and i would feel comfortable doing this retap despite never doing this before, because it doesnt need a lot of torque to hold in there so as long as the tap is semi ok it should work out. my tuner is supposedly on par, but thats what everyone says until their fancy build goes. and that definitely is a mount hole lol......i wouldn't consider than an alternative.

 

its just bizarre how they kept everything the same throughout the LSX generation but some silly stuff they changed, i dont car about them moving the sensors, sure they had their reasons, but why change the threads?