When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
In my last post to this thread regarding post-rebuild oil consumption I was pretty optimistic, however, now that I've completed a 4046-mile oil use these, I'm not that pumped-up about my rebuilt Street Attack LS7.
The engine was filled with Mobil 1 5W30 at Katech at the start of the test. In 4046-miles, oil consumption was 3.5-qt or one quart of oil burned in every 1156 miles. Duty-cycle was mainly highway driving with some city streets in traffic. Oil checking temperature was always equal to or greater than 150°F. Oil checking delay was always 5 minutes after engine shut down.
After my original Street Attack build, in the first 3000 miles the engine used 2.5-qt or a quart every 1200 miles, so apparently, I haven't gained that much at this point.
I had the air filter assembly off the engine a week or so ago then held the TB wide open and used my little GearWrench work light to take a look inside and to my dismay, there is a fair amount of oil inside my intake manifold...almost as bad as what I saw back in early January when I had the TB off and shot images of the inside of my MSD intake.
As for what I'm going to do next....
(sigh)
...maybe buy a catch can? Anyone have any suggestions as to who makes a good one?
I'd like to wish everyone a HappyChristmas and a Merry New Year.
Last edited by Hib Halverson; 12-18-2018 at 08:01 PM.
Reason: added content
Based on the information in this thread the second build included measures aimed specifically at controlling oil consumption. I can't imagine Hib's engine is suffering from the same issues as the previous engine so I would be very surprised if the high oil consumption is a result of cylinder bore finish, ring tension or something related to high blow by. I'm sure the engine was driven fairly conservatively during this break in trip and I can't imagine blow by being a root cause. What are the possible reasons for excessive oil entering the intake air stream? What are the causes of excessive crankcase pressure? The original build also recorded relatively high consumption before ECU tuning resulted in overly lean air/fuel ratios, so I would start looking at all the ancillary systems that are common to both builds. Katech has built countless successful race engines and odds of a machining or assembly error happening twice on the same vehicle are close to zero.
Here is a thought......maybe change out to a higher viscosity oil and or change brands of oil......... just grabbing at straws now, can't believe it is doing the same thing....... that has to have you bummed. I also recommend multiple shots of Pappy Van Winkles Bourbon just to take the edge off........ for medicinal purposes only...... hang in there.......
Up until the end of the first 4046 miles, the calibration in the ECM was what Katech put in there before the car left its facility on 31OCT. Two weeks ago, I made some changes in idle calibration to lower the idle speed a bit, change the minimum airflow table and better calibrate the various tables that affect adaptive idle functions. Part throttle and WOT fuel and spark are unchanged. No other changes have been made.
Eventually I'd like to reinstall my Zip Products air filter assembly and do the "muffler mod" that Josh does. I suspect there's a catch can in my future as well.
At LeMans in 2017, the 5.5L V8s Corvette Racing uses each burned one-half a quart of oil in the 24-hour race. My sources for that are the team of four guys who build those engines at GM Global Propulsion Systems.
Here is a thought......maybe change out to a higher viscosity oil and or change brands of oil......... just grabbing at straws now, can't believe it is doing the same thing....... that has to have you bummed. I also recommend multiple shots of Pappy Van Winkles Bourbon just to take the edge off........ for medicinal purposes only...... hang in there.......
Katech and I agreed that during the initial oil use testing, I'd keep using the Mobil 1 5W30 which they recommended for my engine, however, I think there are better choices, one being Driven Racing Oil's new series of engine oils for directed injected engines the other is Red Line's more traditional 0W40 Fairly soon,
Last edited by Hib Halverson; 01-09-2020 at 01:39 PM.
Hopefully Katech is working with Hib directly rather than thru this thread.
I've been on a holiday road trip to Santa Fe, New Mexico. While we're going to be back in California after the 29th, it won't be until after the first of the year when Steve Spur at Katech, and I have a conference call scheduled.
In the meantime, I'm learning about catch cans. I've tried to contact Elite Engineering to ask some technical questions but they are no real responsive. Next on my list is the makers of the Mighty Mouse CCs.
Yes, we have been following this thread. We have been in contact with Hib and we have a plan. We do not believe this to be a repeat of the same issue. We drove Hib's car for 500 miles before he picked it up and it used 1/4 quart of oil, or a quart per 2000mi. So now it's time to see what else is going on. Just know that we stand behind Hib as we do with all of our customers and we will see this to the end to ensure his satisfaction.
In the meantime, I'm learning about catch cans. I've tried to contact Elite Engineering to ask some technical questions but they are no real responsive. Next on my list is the makers of the Mighty Mouse CCs.
Hib, I think you will find the best why to get your questions answered from both companies is though email.
Certainly, in endurance racing, oil consumption is carefully managed. The Cadillac DPi engines by ECR Engines also have extremely low oil consumption reducing the time required for pit stops. Personally, I highly prefer an engine that uses little to no oil between drain intervals.
Originally Posted by Hib Halverson
(snip)
Not sure I'd agree with that in all cases.
At LeMans in 2017, the 5.5L V8s Corvette Racing uses each burned one-half a quart of oil in the 24-hour race. My sources for that are the team of four guys who build those engines at GM Global Propulsion Systems.
Hib, I think you will find the best why to get your questions answered from both companies is though email.
I called Elite and talked to its voice mail. A few days later, I received an email from "Steve" at Elite. I emailed him back some questions but he never replied. I don't have any more time for a company which won't respond to product questions from prospective coustomers.
I have not contacted the people at Mighty Mouse but will do so on 2JAN19.
Comes in the kit from Mighty Mouse. He gives you everything that you need. I also bought some slip on connectors and 3/8 hose from him and got rid off the plastic lines on the sump.
Yes, we have been following this thread. We have been in contact with Hib and we have a plan. We do not believe this to be a repeat of the same issue. We drove Hib's car for 500 miles before he picked it up and it used 1/4 quart of oil, or a quart per 2000mi. So now it's time to see what else is going on. Just know that we stand behind Hib as we do with all of our customers and we will see this to the end to ensure his satisfaction.
Have a safe and happy new year!
-The Katech team
I was aware that Katech's guys were going to drive the car 500 miles before I picked it up to gauge oil use and I was definitely OK with that, however, I was not until I read the above that I knew it was using about a quart every 2000 miles before I picked up the car on 31OCT. That number is actually better than what I saw in my own oil use test which was 3.5-qt in 4046-mi.
What I'm not sure about is if Katech and I were both using identical dip-stick "full" marks and oil checking procedure. I'll get all my oil check imagery together and post it tomorrow or Monday.
Happy New Year everyone!
Last edited by Hib Halverson; 12-29-2018 at 09:29 PM.
Yeah, there's news but, all I'm going to say that this point is the engine's oil use has gotten no worse or not better. Before I post anything more, I'm supposed to talk to Steve Spurr, Katech's President by phone either tomorrow or Wed. I need to hear what Steve has to say before I post anything more.
In the meantime...happy New Year, all.
Last edited by Hib Halverson; 01-07-2019 at 11:18 PM.
The good news is that, now that I've got nearly 4100 miles on my rebuilt Katech Street Attack LS7, I'm starting to hammer it and that motor is bad-*** at wide-open-throttle.
It pulls hard to the rev limiter with little or no knock retard which is amazing considering my testing was on 91-oct fuel, at sea level with a 66° IAT. Injector duty cycle peaked at 92-95% at 6800-RPM. I'm ok with that, now, but if I were to start tracking the car a lot, I'd need an injector change. After the original build, the engine was ingesting a lot of oil and there was a lot of KR as a result of oil's very low octane.
Here's a link to what I saw behind me once I had 3000 miles on the original build. The footage was shot one year ago on 14JAN2018, before I started screwing with WOT fuel and spark.
The good news–no, actually it's great news–is with the rebuild, there is no oil smoke at any rpm under high load..nada, zilch. Whatever Katech did differently during the rebuild solved that problem. My compliments to Dean at Katech who assembled the engine.
The bad news is that when I pulled the throttle body, I found a lot of oil behind the throttle plate and inside the intake manifold. I had that problem with the original build and, apparently, I'm having it with the rebuilt engine. I shot a bunch of pictures and sent three of them to Katech. They're also posted here. My belief is that level of oil inside the intake, combined with the engine's documented oil consumption and the fact that there is no oil going out the exhaust this time, point at some kind of oil vapor control problem with the positive crankcase ventilation (PCV) system. The original build used a Katech Red Oil pump which generated nearly 100-psi hot, most of the time, even with a 5W30 oil. That made no sense to me, so for the rebuild I requested the Katech Blue Pump which has an output pressure close to stock. With that, oil pressure was more reasonable, 50-60 psi hot, so, with windage due to excessive oil pressure now not an issue, I began thinking about flow through the PCV system. Katech leaves the stock air/oil separator in the valley, so the only change is Katech's rocker covers. I pulled one and looked inside at where the fresh air hose coming from the oil tank connects to the cover. Then I got my stock covers out of storage and imaged the air/oil separators inside them. As you can see, there is quite a difference in design and that raised a couple of questions in my mind, but first, let's review the basics of the Gen 4 dry-sump PCV system. Engine vacuum is applied to the air/oil separator inside the valley. That lower pressure causes crankcase gases to flow through the separator and into the intake to be combusted by the engine. Fresh air flows from connection on the air bridge, to the dry sump tank, then to both rocker covers and into the rocker boxes. Then, it flows down, into the crankcase, then up, through the valley air/oil separator and into the intake.
Obviously, proper oil vapor control is dependent to flow through the system. My first question is: does the lack of OE-type air oil separators in the Katech covers significantly change gas flow though the engine when the PCV system is operating normally? If the level of restriction in the system changes, then flow might change. Do the restrictions posed by the passages in Katech rocker covers provide the same level of restriction as do air/oil separators in the stock rocker covers? If not, would the difference in flow though that system be significant enough to change the amount of oil vapor ingested by the engine?
Inquiring minds want to know, so the next step, as a way to test a question about flow rate though the system, might be to replace the Katech rocker covers with the stock covers, then measure oil use. Before I can do that, I need to obtain some stock coil mounting brackets as my originals got scrapped after the Katech covers were installed. Silly me, huh. Donations of stock LS7 coil brackets will be accepted.
Ok, now, let's consider at what happens in the PCV system at high rpm and high MAP. Once the manifold pressure nears atmospheric, flow though the "fresh" side of the PCV slows and even may reverse at high RPM due to crankcase pressure. When that happens, you may have oil vapor flowing both from the crankcase into the engine though the valley separator and from the rocker boxes into the fresh air hoses to the oil tank. My next questions are about the the connections on the sides of the Katech covers. Once oil spray and windage inside the rocker boxes enters the normally-fresh-air passages in the covers, it appears to me that those passages may not act as air/oil separators, so hopefully, the oil tank, itself, serves that purpose with "oil-less", reverse air flow going out of the tank to the air bridge and into the throttle body. I am banking on my rebuilt Street Attack's improved oil control–due to changes in piston material, changes in piston-to-bore clearance, different oil ring tension and different bore wall finish–preventing any problem with oil vapor when flow in the fresh side of the PCV system reverses. I'lll add there is no evidence that oil is getting into the hose that runs from my oil tank to the air bridge. Steve Spurr, Katech's President and Jason Harding and I did a conference call last week. They asked me: 1) to continue the oil use test using Mobil 1 5W30 for another 1000 mies, 2) before doing that, remove the TB, again, and try and "soak up" as much oil from inside the manifold as I can, 3) use a revised oil level of between the bottom mark and the middle mark on the dip stick and 4) not install a catch can, yet. All of these are reasonable requests with which I'll comply, but on #2, I think a better solution is to just pull the manifold and drain it. I'm, also, going to delay installation of a set of JoshB mufflers and my Zip Products Mamba air filter assembly.
During the conference call, we had a discussion about my calibration changes to idle speed, idle spark advance and adaptive idle spark timing. Steve Spurr was disappointed that I had violated our agreement that I would not change anything in the engine's cal. My position was: 1) that agreement applied only to the first 4000 miles of oil use testing and 2) since the only changes were to idle speed, idle spark and adaptive spark and the engine spends so little time at idle, changes to idle calibration have no practical effect on oil consumption.
The last piece of news is, now that I've got 4100 miles on the engine, I'm going to schedule chassis dyno time at my normal test venue, Westech Performance Group in Mira Loma, California. I'll post the results after I run on Westech's dyno.
Last edited by Hib Halverson; 01-13-2019 at 03:41 PM.
The good news is that, now that I've got nearly 4100 miles on my rebuilt Katech Street Attack LS7, I'm starting to hammer it and that motor is bad-*** at wide-open-throttle.
It pulls hard to the rev limiter with little or no knock retard which is amazing considering my testing was on 91-oct fuel, at sea level with a 66° IAT. Injector duty cycle peaked at 92-95% at 6800-RPM. I'm ok with that, now, but if I were to start tracking the car a lot, I'd need an injector change. After the original build, the engine was ingesting a lot of oil and there was a lot of KR as a result of oil's very low octane.
Here's a link to what I saw behind me once I had 3000 miles on the original build. The footage was shot one year ago on 14JAN2018, before I started screwing with WOT fuel and spark.
The good news–no, actually it's great news–is with the rebuild, there is no oil smoke at any rpm under high load..nada, zilch. Whatever Katech did differently during the rebuild solved that problem. My compliments to Dean at Katech who assembled the engine.
The bad news is that when I pulled the throttle body, I found a lot of oil behind the throttle plate and inside the intake manifold. I had that problem with the original build and, apparently, I'm having it with the rebuilt engine. I shot a bunch of pictures and sent three of them to Katech. They're also posted here. My belief is that level of oil inside the intake, combined with the engine's documented oil consumption and the fact that there is no oil going out the exhaust this time, point at some kind of oil vapor control problem with the positive crankcase ventilation (PCV) system. The original build used a Katech Red Oil pump which generated nearly 100-psi hot, most of the time, even with a 5W30 oil. That made no sense to me, so for the rebuild I requested the Katech Blue Pump which has an output pressure close to stock. With that, oil pressure was more reasonable, 50-60 psi hot, so, with windage due to excessive oil pressure now not an issue, I began thinking about flow through the PCV system. Katech leaves the stock air/oil separator in the valley, so the only change is Katech's rocker covers. I pulled one and looked inside at where the fresh air hose coming from the oil tank connects to the cover. Then I got my stock covers out of storage and imaged the air/oil separators inside them. As you can see, there is quite a difference in design and that raised a couple of questions in my mind, but first, let's review the basics of the Gen 4 dry-sump PCV system. Engine vacuum is applied to the air/oil separator inside the valley. That lower pressure causes crankcase gases to flow through the separator and into the intake to be combusted by the engine. Fresh air flows from connection on the air bridge, to the dry sump tank, then to both rocker covers and into the rocker boxes. Then, it flows down, into the crankcase, then up, through the valley air/oil separator and into the intake.
Obviously, proper oil vapor control is dependent to flow through the system. My first question is: does the lack of OE-type air oil separators in the Katech covers significantly change gas flow though the engine when the PCV system is operating normally? If the level of restriction in the system changes, then flow might change. Do the restrictions posed by the passages in Katech rocker covers provide the same level of restriction as do air/oil separators in the stock rocker covers? If not, would the difference in flow though that system be significant enough to change the amount of oil vapor ingested by the engine?
Inquiring minds want to know, so the next step, as a way to test a question about flow rate though the system, might be to replace the Katech rocker covers with the stock covers, then measure oil use. Before I can do that, I need to obtain some stock coil mounting brackets as my originals got scrapped after the Katech covers were installed. Silly me, huh. Donations of stock LS7 coil brackets will be accepted.
Ok, now, let's consider at what happens in the PCV system at high rpm and high MAP. Once the manifold pressure nears atmospheric, flow though the "fresh" side of the PCV slows and even may reverse at high RPM due to crankcase pressure. When that happens, you may have oil vapor flowing both from the crankcase into the engine though the valley separator and from the rocker boxes into the fresh air hoses to the oil tank. My next questions are about the the connections on the sides of the Katech covers. Once oil spray and windage inside the rocker boxes enters the normally-fresh-air passages in the covers, it appears to me that those passages may not act as air/oil separators, so hopefully, the oil tank, itself, serves that purpose with "oil-less", reverse air flow going out of the tank to the air bridge and into the throttle body. I am banking on my rebuilt Street Attack's improved oil control–due to changes in piston material, changes in piston-to-bore clearance, different oil ring tension and different bore wall finish–preventing any problem with oil vapor when flow in the fresh side of the PCV system reverses. I'lll add there is no evidence that oil is getting into the hose that runs from my oil tank to the air bridge. Steve Spurr, Katech's President and Jason Harding and I did a conference call last week. They asked me: 1) to continue the oil use test using Mobil 1 5W30 for another 1000 mies, 2) before doing that, remove the TB, again, and try and "soak up" as much oil from inside the manifold as I can, 3) use a revised oil level of between the bottom mark and the middle mark on the dip stick and 4) not install a catch can, yet. All of these are reasonable requests with which I'll comply, but on #2, I think a better solution is to just pull the manifold and drain it. I'm, also, going to delay installation of a set of JoshB mufflers and my Zip Products Mamba air filter assembly.
During the conference call, we had a discussion about my calibration changes to idle speed, idle spark advance and adaptive idle spark timing. Steve Spurr was disappointed that I had violated our agreement that I would not change anything in the engine's cal. My position was: 1) that agreement applied only to the first 4000 miles of oil use testing and 2) since the only changes were to idle speed, idle spark and adaptive spark and the engine spends so little time at idle, changes to idle calibration have no practical effect on oil consumption.
The last piece of news is, now that I've got 4100 miles on the engine, I'm going to schedule chassis dyno time at my normal test venue, Westech Performance Group in Mira Loma, California. I'll post the results after I run on Westech's dyno.
So with there disappointment with you changing the tune are they voiding your warranty?
12-18-2018, 07:27 PM
