Got a small win tonight. The new oil pickup tube fits properly. Something definitely changed in the production since early 2018 when I got the first batch of parts. Now I don't have to cobble up anything.

I needed that win too...

I have an Improved Racing tube brace but didn't use it first time around because Holley puts a big weld blob right in the way. But I cut down the brace to clear the two welds and it's going on this round.

 

great news! here's a pic of my holley pickup tube. does yours look similar? like i said, mine came with a 2 bolt mounting flange right out of the box. sounds like yours didnt?

 

Went for a drive today and noise is still there. I'm out of ideas.

I asked some people next to me at a stoplight if they heard a clicking noise and they said no. That's interesting and also hard to explain because I heard it loud and clear in the cab.

 

Usually paranoia enhance sensitivity to senses

i tried to listen to video couple different speakers
And really don’t hear any ticking I do hear rattling
But could be the exhaust distorting the sound
But with that sound if it’s accurate to what you hear sounds
more like clutch exhaust or one of the pulleys but
hard to say but really doesn’t sound like anything wrong with engine

Enjoy her already lol

 

See if you can find one of the mechanic listening device, it has several wireless mics that you put on suspect parts and it let's you cycle through the mics to see where it's loudest.

 

I'm going to have some friends listen to the tapping noise but I'm not expecting any more revelations. Going to start driving the car while keeping my eyes and ears open. Not confident enough yet to hand it over to a shop for a dyno tune though, so I'll just do a little street tuning in the interim. Good news is that it only took a few drives to dial in idle and street manners. All I've got left is tune for power and throttle response but that's pretty much impossible to do without going waaaaaaay too fast for the street.

This time around I have fuel pressure on the laptop. Looks like fuel pressure goes lower than I had anticipated so now I am pretty much expecting to run out of fuel before the engine makes peak power. That sucks because the next step up is not cheap. I'll just see what happens though because I'm not rushing to spend a lot more money on this thing.

 

I'm sure its somewhere in this thread, but which pump are you running? I just noticed aeromotive has a baffled tank with a 340lph pump specifically for thirdgens which is supposed to support 700hp for $550. I didnt have a chance to see how it works with the stock cluster though. I assume 675-700 hp is right around where you are at the crank.

 

what injectors your running ? have you de-capped them
what's your duty cycle at ?

and the pump can always run 2nd inline one as well for
not to much

 

what injectors your running ? have you de-capped them
what's your duty cycle at ?

and the pump can always run 2nd inline as you already know

 

60 lb/hr Bosch tall body EV6. FOMOCO injectors actually, and I'm not ashamed about it.
I don't know what you mean by de-capped... ?

Thanks for the lead. I'll go take a look at it.

More. These Mamo LS7 packages are incredible with street manners. I know what it will do in a C6 Corvette. Never seen one run in a F-body yet with single exhaust and such. I already can tell you that I can drive slower with less surge than my old engine, and the car never moved so fast even at part throttle and radically conservative ignition timing.

 

On factory style injectors de-capping almost doubles flow

those injectors should flow to support above 700 rwhp
Nothing to be ashamed rather have a over achieving fuel
system then under as usually that’s the usually set back in many builds when hitting the dyno
aeromotive have ave some good pumps internal and external

 

Im excited to see what it dynos at and traps at. My LS7 is going to look very similar from a build perspective.

 

But what do you mean "de-capped"?

 

On stock style injectors there’s a cap at the end it restricts flow so
removing them removes the restriction so injector can flow more fuel

its useful modification to get more flow and working with what you got
for budget minded people or give you time until you buy higher flow inj
depending on your build power needs a lot guys do it on other car platforms
and usually seen once you start needing 50lb or more
highest flow for stock injector are ls9 which is at 48lbs I believe
fuel pressure plays a role as well but your duty cycle in tune will
tell you on your fuel needs and fuel pressure as well

 

I see, that makes sense, but does it make a difference in how the spray pattern is directed in the port?

 

The battle of the 427's begins.

The old engine was a 427 6.0L stroker with ported L92 heads and FAST 102R intake. The new engine is a 427 LS7 with ported Trick Flow heads and ported MSD intake. Cam specs are virtually identical. Same injectors, headers, and exhaust.

I got a baseline pull today on the LS7 before tuning. I was carrying a passenger. Car went 75-100 mph in 2.5 sec in 3rd gear with only 20 degrees of timing. Injectors climbed to 80% duty cycle to maintain enough fuel supply (pressure is dropping). In addition to a larger fuel supply, it looks like I might need a less restrictive intake tube because MAP value was at 97 kPA.

Comparison wise, that is right on top of the best times the 6.0L stroker ever managed with no passenger aboard. Injectors would have been at 58% duty cycle. One of my old data logs the 427 stroker did 2.2 sec 75-100 mph.

We'll see what happens with tuning and whatever else I need to do. One thing about the LS7 is the fuel demand skyrockets past the 6.0L stroker above 5500 rpm. More to come....

 

And...? Did I miss a post about any results?

 

There is also a wireless version, but it lets you put the mics over the engine or suspension and then switch between them to narrow down where the noise is coming from. Also you could try a different weight of oil and see if things change.

 

The tapping noise did not change with any of my work. Couple of my friends think it is lifter noise but they admit it is very curious why the noise is louder in the cab than in the engine bay. One of them has Morel lifters and says those are louder.

I've been driving and beginning the process to sort things. The 4" air intake appears a bit restrictive but the big issue right now is fuel supply. The data is telling me there is more than one issue causing fuel pressure drop. There is a stair-step drop that I don't think has anything to do with pump capacity. And then there is an aggressive pressure ramp down as the engine truly begins to exceed pump capacity. I think the LS1 F-body pressure regulator is the cause of the stair-step; and the ramp down is a classic case of pump capacity, supply voltage, etc.

 

The other thing I did is raise the height of the car a bit. From a visual standpoint the tires now look meatier and wider and I'm digging the new look. And the car is getting better traction too.

The front end naturally raised up with the weight loss after the engine swap. The rear springs have always been ridiculously short with the Ground Control weight jacks, so I custom ordered new springs that are 2" longer to take up the slack. The new springs are perfect with the weight jacks at lowest setting. The stiffer spring and higher ride height is doing a better job of keeping the axle off the rear snubbers and the car is hooking up a lot better on the street. There's hope on the horizon that I can beat a 2.0 sec 60' time!

 

This is a story worth sharing. I called Quiet Ride to order a new firewall pad with the intention that I would cut it in half and replace passenger side. The salesman was listening to my sob story and and offered to send me a piece of 4'x4' scrap for the cost of shipping. I hardly think that large of a piece is "scrap", which makes the offer even more generous. The package arrives and not only is there a brand new pad inside, but they threw in a large can of 3M spray adhesive too! That was just so generous and kind!

And I couldn't get the pad installed soon enough. All i can say is the floor pan get freakin' HOT with long tube headers! And the lifter noise is barely noticeable now with all that padding and carpet in place.

 

I have a Racetronix GSS340 (Walbro 255 lph ) in a 4th gen fuel tank. I've been looking at larger fuel pump options but I can't go any larger without losing the venturi feature that keeps the pump submerged in the fuel bucket. So I decided to try a Kenne Bell Boost-a-Pump to increase voltage at the fuel pump. It's a lot cheaper than a lot of fuel system options, and very easy to install. We'll see how far that takes me. I might control it with the Holley HP EFI instead of using the vacuum switch that comes with the kit.

I spoke to Lingenfelter about fuel filters and they started quoting numbers from charts that they've created over the years. The 4th gen OE fuel filter is maxed out around 270 lph before it causes too much pressure drop. The C5 Corvette filter isn't any better. Also, the OE filter has 5 micron filter media which is much better than aftermarket filters that I've seen. I think what I might do is install two OE filters in parallel. That way I have easy access to inexpensive service parts.

I'm going to leave the 4th gen pressure regulator in place for now and see how things behave after the Boost-a-pump. I don't relish dropping the fuel tank so I'm not dealing with it unless I have to. I don't care if pressure drops some as long as it is consistent and I can tune around it.

 

i think it is a good idea to try the voltage booster, it should help.

i can't recommend this yet personally as i have not yet tried it, but this is what i will be trying on my next large LS build... holley hydra mat... should let you open up the fuel bucket and have it act it place of the bucket effect so won't need the venturi feed...

https://www.summitracing.com/parts/hly-16-111/overview/

i really like using the 4th gen tanks for many reasons and personally will not go back to the 3rd gen style so i have been thinking about this for a while on what i will try next build

 

Alan, have you used the hydramat before? I have the large mat and it will be too much fab work for my stock tank. The one you posted has a different attachment (Non AN). Do you know if that fits on the pump like a traditional fuel sock? If this doesnt work, I plan on cutting the stock bucket out and fabbing an AN fitting onto the OEM sending unit pickup. Or just abandon it for an aeromotive fuel tank kit that was recently brought to market.

 

So I looked into this HydraMat last winter when i was beefing up my fuel system. I called and emailed holley (and even had a thread here on TGO about my fuel system upgrade) in the end I was left to the determination that it would not work with my racetronix 340 lph in tank pump in a 3rd gen tank. my main dilemma was, how would I mount the hydramat and keep it from sloshing around in the tank (i wanted to use magnets), and at the same time get the mat connected to the pump? I was told it wouldn't work??!? So, I have done a few autocross events since then and have had no starvation issues because I keep the tank over 1/2 full capacity. I know you dont want to drop the tank(nobody does) but maybe the 340 lph pump would help? I am sure it could physically be made to work with the hydramat, but it wasn't something I wanted to experiment with at the time. if you do go that hydramat route, keep us updated.

 

again, I am just going by what I have researched and haven't tried it myself yet. the one I showed the part number for from summit is supposed to mount to the pump fitting just like you typically do, ie a push on type fitting (not AN)… if this is the case, what I was thinking of doing was cutting a couple of holes in the bucket and placing this in the bucket / letting it even exit the bucket. this would place the hydra mat at the bottom of the tank and be held by the bucket... it is just a thought in process so can't comment on how well it works or not... yet

 

Flipping topics agains because I'm fixing random stuff today. Or thinking about fixing it anyway.

My headlights always turn on, but most times the doors will not raise until I wriggle the harness. And the doors always fold down when lights are turned off.

I found a schematic and drew some colored circuits on top of it to help me understand what is happening. I've concluded the problem must be either the relay on the headlight module circuit board, or an intermittent connection at Terminal A of the connector. I'll put it on my to-do list and take a closer look at it one of these days. Just writing it down here for future reference.

Update: Using a C5 Corvette headlight module, Post #1561, https://www.thirdgen.org/forums/ltx-...ml#post6402215






I've also long wondered how the hatch pull-down motor works so I put together some graphics for that too. Nothing wrong with mine, but figure this will come in handy in the future.

 

it is somewhat common that the headlight control panel on the firewall ends up having the connectors make intermittent connection to the PCB board inside. i had this issue on my son's 87 formula. it is relatively easy to open up the black case by going around the back edge with a knife (you will see how it goes together when you have it out. once you gently are able to pry that apart then you will be able to easily see if you connector is a wobbler. i resoldered both connectors and put it back together. has worked 100% for a couple years now

the headlights can have this problem and then also the problem with the motors themselves that need new bushings installed

generally though if you are able to move the harness around the firewall panel and it corrects it, pretty likely the connector on the board is loose

 

Thanks, I'll check it out.

 

Mine years ago rubbed the wire until it shorted to ground. It would do that and eventually fried the controller.

 

It was bugging me not knowing the true specs of my old 427 stroker so I put it on the engine stand and got into it. And lo and behold a few mysteries have been solved.

The mystery of compression ratio --- Turns out it was a pretty nice set up with 64 cc heads at 11.8 compression. I did not expect that! PRC L92 heads are 70cc if I remeber right, so the heads were milled down by special request. The piston fly cuts were also smaller than I had assumed (-6.5 cc), hence the high compression ratio.

The mystery of camshaft timing --- And it turns out that the cam was installed 5 degrees too far advanced. No wonder the engine peaked so early! That's my fault of course. Chalk that up to using a small 7" wheel in the engine bay, and my lack of experience at the time. So with the engine on the stand I mounted up my 16" wheel and degree'd the cam to the gnats *** where it should be. Instant power gain.

There's no reason that engine shouldn't bust the 500 RWHP barrier now. Too bad I didn't figure that out when it was in my car.

 

And speaking of 500 RWHP.... I'm starting to believe that's all my car will support from an n/a engine. The LS7 is being choked from all sides (intake, exhaust, fuel) to about 500 RWHP. On the plus side the car isn't slowing down at all in the hot weather.

The 4" intake had maybe 1 kPa pressure drop with the 427 stroker. The LS7 is causing a 3 kPA drop, and would be even more if I revved the engine higher. I don't know what the engine really wants so I'm going to fab up a 5" intake and see what happens.

The fuel pressure is dropping but the fuel flow is still there. The 60 lb/hr injectors are at 80% duty cycle when at low pressure and don't act starved for fuel. I'm installing a Boost-A-Pump to stabilize pressure and support more power if I can free up the engine's breathing.

And then there's the 3.5" exhaust.... Man, I was hoping it wouldn't hurt me that much but I'm starting to think it's mostly responsible for cap on power. I'm not sure how much exhaust this engine really wants but it's probably 3.5" duals. I'm not doing that. Not even sure I'm willing to do 3" duals. But if I don't change exhaust then the LS7 was likely a complete waste of time and money. Going to have to chew on this for a bit.

 

4" system from mufflex is an option
-probably what I am going to do in the spring 2020 after the new engine is put in over the winter

 

I've talked about first principles before and it's directly aimed at adequate intake and exhaust no matter the power output.
You may want to investigate having sufficient air filter area. The cone filters I've seen used are short on what's required for any reasonably healthy engine. K & N have a chart for calculating sq in required per hp. Might be something there.
As for the exhaust, that's always a compromise on these cars. It's not an easy task trying to establish 2.2 CFM/HP so as to avoid the point where output starts to be reduced by the restricted capacity. Then of course there's always the strategically placed cutouts that will give you what you want when you really need it, as in track days. Then the LS7 can really breathe.
For the record, we feed the LSX454 with a 4x14 filter element and exhaust through dual 3". What does it take to get a 3700 lb brick to run 10.99 @ 126? I say 500 rwhp at least. Engine dynoed 650 at the crank.
PS: I'll emphasize "strategically placed" as simply dropping the exhaust after the short header collector will (almost always) result in a net loss of power.

 

I agree above you need to place cut outs in and see how it reacts or go 3" duals or a 4" with cut out
which is hard decision due to the fact its a added maintenance item and cant always
open them during street driving hooker has a nice dual in for our cars but its only 2.5
https://www.holley.com/products/exha.../70501439-RHKR
the rpm your able to run on a LS7 even a 4" will be restrictive
and is a challenge when it comes to intake exhaust and fueling
hence why you start to see the shift into custom intakes and or
other intakes vs the composite

 

here's a guy selling a basically brand new 4" mufflex system apparently
https://www.thirdgen.org/forums/engi...bird-82-a.html

in washington $500 plus shipping

 

that muffler doesn't flow as well as a straight thru and can build a 4 in for less than that

 

Still chewing?

 

Been reading parts of this thread because on my build I’m going with a LS7/700hp. I’m looking at the Hawks setup that QwkTrip has on his car. Mainly because it’s all bolt on and has 2” long tubes and is all stainless. The single exhaust pipe outlet is what I have questions about. Do you think it hampers your performance QwkTrip? And did it fit and bolt up as they claim? Also have a buddy who built a LS7 for his Vette and had a similar noise. Was louder in the car. Turned out to be a defective lifter.

 

First I need to fix the other stuff, and then I'll have dyno numbers and a quarter mile run later this year if you can wait a bit. Engine can normally exceed 600 RWHP on most dynos. That will be about 575 RWHP on the dyno I will tune with. We'll see how far short I fall of that number.

Exhaust system is very nice. Everything fits really well except one really annoying issue.... Passenger side header collector is hard up against the car subframe. It used to be really close and rattle on the subframe with the LS3 heads. But now it's flat out laying on the subframe with the LS7. But it doesn't rattle anymore! LOL

 

No hurry. My car just went to paint and body shop. What brand subframes are you running? I'm using UMI. LMK when you do all the testing. I'd like to see just how well that exhaust system performs.

 

I have Kenny Brown round-tube outer subframe connectors from 20 years ago, and added Alston inner subframe connectors more recently.

The outers alone weren't suffient after the 427 LS. All the body panels moved after first summer of driving and there were early signs of roof cracking. That got me worried so I threw everything at it with the Alston's and a street friendly 6 point cage. Nothing has shifted or cracked since.

 

I installed a 6-point cage for those reasons. Knew if I didn’t I’d have body flexing issues. Hope you get all the bugs worked out so you can enjoy your car.

 

The 427 stroker is now up for sale.

https://www.thirdgen.org/forums/lsx-...gine-very.html

 

 

My clutch is acting funny so I had to flush and bleed the whole system. Fluid was black as sin after 5000 miles. But as I lay under the car preparing for the job I was reminded how much a PAIN IN THE TUSH and MESSY it is to bleed a T56. No way! No how! I'm not doing it this way again!

I don't use a remote bleeder because those things are prone to leaks by the quirky way they adapt to the slave cylinder. The T56 bleed valve is only about an inch away from the floor pan, so I took a couple measurements and cut a 1-1/4 inch hole thru the floor pan right in front of the bleed valve. Talk about an easy job now! I ran an entire bottle through in about 10 minutes with no mess. And I can see thru the tube and know when I have flushed out all the old fluid and air bubbles.

Put the rear of the car up as high as you can. Crack the valve with a 7/16" socket, and then push a 3/8" clear hose over the valve. The valve can be opened and closed by turning the hose. Once done, just grab the hose with a paper towel, turn and pull the hose (to make sure the valve doesn't loosen), and then final tighten the valve with the socket. I'm going to RTV a patch over the hole so I can peel it off again the next time I need access.

 

Car night in America.

It's cool even when it's broken.

 

My recommendation: Get a steel push-in 1-1/4" plug from the hardware store to cover the hole.

 

This summer the sleeve around the seat belt receiver finally ripped apart, causing the latch to flop around like a limp noodle. So I got hold of a new replacement from Hawks Motorsports and installed it tonight. Super easy and took no more than 10 minutes.

There is one noteworthy thing I learned this time around: I always had trouble in the past with the torx bit slipping when trying to turn the bolt in the floor. Well, this summer I became aware of something called Torx Plus. I looked at the bolt head and sure enough it was a TP45 Torx Plus! It was soooooo easy when using the right tool!

The original seat belt can't be pulled out of the sleeve without first drilling out a pinched area at the mounting bracket. I ran a step drill thru until the seat belt became loose. Looks like I uncovered a dirty little secret though.... GM must have run out of grey seat belts and used a tan belt in my car!




The new sleeve was tighter than the old, and the seat belt got stuck before I could get it fully inserted. I used an old trusty beer bottle opener to hook it from the bottom and pull it the rest of the way. (If that were to fail then I would fish some metal wire through the sleeve and tie it to the seat belt and pull the belt through.) A plastic pin is provided to anchor the seat belt again. That's it! Really simple job! Just use the TP45 bit to reinstall the floor bolt to 31 lb-ft.

 

I've been driving all summer on a conservative tune due to lack of fuel above 5000 rpm. I just got done tonight installing a Kenne Bell Boost-A-Pump, so hopefully now the real engine tuning can begin. Based on Kenne Bell lab tests, the Walbro GSS340 pump should now deliver +100 L/hr fuel flow (37% increase). That's enough to support about +200 Hp at the crank.

I got the naturally aspirated Boost-A-Pump, part number KB89068. It is basically a voltage booster & voltage regulator for the fuel pump that is actuated by a vacuum switch. It's a simple design that goes ON when there is no engine manifold vacuum, and turns OFF when there is vacuum. I won't be using the vacuum switch though. I am using the Holley HP EFI so to have more control of ON/OFF parameters.

When the Boost-A-Pump is active it regulates voltage to 17.5V, even if system voltage drops. So it's not just a voltage offset, it actually regulates to 17.5V. A pill can be plugged into the unit that will cause it to regulate to 21V. But that is not recommended as it will kill a Walbro 255 pump in quick fashion.

The BAP comes with a really nice connector on the fuel pump wires.... except they don't provide the mating parts and there are no instructions what to buy. So after playing Sherlock Holmes, I figured out the mating connector is Metripack 630 series connector, part number 12033769, with pull-to-seat terminals 12033997 for 10-12 AWG wire.




First I had to find a home for the BAP unit. I have 10 AWG wire running under the interior sill plate, so it made sense to mount the unit under the driver seat where I could get easy access to the wire. Plan 'A' was to simply velcro the box to the carpet, but it turns out that velcro won't stick to the carpet. Not even a little bit. Can you believe that?!

And on to Plan 'B', which was to shave off the carpet (literally with an electric shaver) and glue a velcro pad to the backing. I was hoping to find a plastic surface, but it was fabric with a seemingly endless supply of lint. I did my best to de-lint the surface and glued down a couple velcro pads. It actually is holding to my surprise. If it comes off then no harm done, I'll just move on to Plan 'C' by sticking the box directly to the floor pan. I'll tell ya, a couple years ago I would have been appalled at the idea of cutting up a $500 carpet. LOL! Installing the roll cage fixed any aversion I have to that.






This is where things got a little goofy. I'm out of Output drivers in the Holley HP EFI, but I don't have air conditioning any more, so I repurposed the AC relay to operate the BAP. But all the relay does now is close the contacts so the BAP will be triggered to activate. There is no external power to the relay contacts any more.

I've programmed the HP EFI to turn on the BAP when engine MAP is greater than 90 kpa, or engine speed is greater than 4000 rpm. I've also programmed a delayed shut off until engine speed is less than 3000 rpm. The 4000 rpm turn-on is so that the BAP is already engaged if I'm rolling into the throttle. The delayed shut-off is so that I can play with throttle (change of mind) and not have the BAP unit cycling on/off. I might come up with other conditions, but that's my starting point for now.

Another significant finding is that when I had the fuse box apart I noticed my 10 AWG fuel pump wire was fed by a teeny weenie little wire from the fuel pump relay. I couldn't go through all this work and NOT upgrade the fuel pump wiring. So I built out my own 'Hot Wire' kit with 10 AWG wire all the way to the battery, ATC fuse holder, and Bosch 46A relay.

Phew! That was a long post!