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Engine SwapEverything about swapping an engine into your Third Gen.....be it V6, V8, LTX/LSX, crate engine, etc. Pictures, questions, answers, and work logs.
The 5746 PN drags up more than one gasket assigned to that PN. The Clevite 5746 comes in a Victor Reinz package (as seen in the accompanying picture).
I've used this gasket on more than one occasion with Vortec heads. I've never had a issue with cooling. I've also heard of the "missing coolant hole" however, installing this gasket , as is, has presented zero issues in any regard.
If you wouldn't mind, can you post a link to the conversation you've come across regarding compatibility? I've read them but don't have a record of what was posted and where.
Last edited by skinny z; Jan 26, 2017 at 04:32 PM.
This is getting silly. We ordered the VR 5746 gasket. This is what we got from Summit. The package says it is non returnable if opened. So we can't open it to check the thickness without getting stuck with it if it ain't the Victor Reinz we ordered.
What's the part number on the package? The 5746 is sold under a number of brand names. I've seen it listed as Clevite, Cometic, VR.
Seems there's a Mahle 5746 too. https://www.summitracing.com/int/par...5746/overview/
I'll check through the Mahle catalogue (if I can find it).
Here's the 5746 in Mahle form. It's entirely possible it just says Mahle on the package instead of Clevite now, since it's all the same company anyways.
From the Mahle High Performance catalogue.
It has the same specs as all of the other 5746 gaskets. .026" compressed thickness and a 4.100" bore. Nitroseal. Etc.
Not sure if you're keeping up with the math TA Dad but a quick calculation shows your SCR/DCR at 10.28/8.26. That's with 4.00" x 3.48", .0126" average piston to head clearance, .026" x 4.120" gasket, 64 cc heads, XR276HR (installed on a 106 ICL), piston with 5 cc valve reliefs.
Experience from my similar build says that will be a crisp and responsive engine. A guess on the cranking pressure would be close to 200 PSI (depending on your elevation).
I don't think you'll be disappointed. Just be on top of the tuning.
If I waited until the weekend it would be a year since I posted in this thread. Time flies when you're not working on the car! My SIL who is the mechanic brains of this operation bought a repo house and gutted it and rebuilt it. I've been helping and the engine has been sitting in the shed wrapped in plastic. Time to get back to work.
After the extensive gasket discussions we bolted the heads on before the break. I need to reread the info we were given about pushrod length so we can move forward with the roller rockers.
Todays question is hopefully simpler. (Famous last words). My son would like orange valve covers that don't say Chevrolet. While it is a Chevy, it's in a TA and it just doesn't feel right. Having trouble finding orange center bolt valve covers that don't say Chevy or some thing that the engine doesn't have like Holley.
And do we need a tall valve cover because of aftermarket roller rockers?
We'd like cast aluminum valve covers because we think they'll be better are not leaking, is that a valid thought?
To summarize the video, I don't think the roller rockers really made any difference at all. They didn't really gain anything until they went with a higher ratio rocker. And then, it's the rocker ratio that helps out, not the roller. If I could redo it, I'd probably of gone with 1.6 stamped steel rockers. The Scorpions I run have been nothing but a pain.
Relating to my own experiences the cast aluminium valve covers (Proform ) had leaking issues. What's more is the hardware was terrible and wasn't up to the task. To solve the leaks, I glued a silicone gasket to the cover. Then it was only one surface that had the potential to leak. For the hardware, I used socket head bolts and cut them to length as each side was different. Then I was able to provide maximum clamping force and the leaks stopped. Except for the poor seal where the bolt passes through the cover. I had to cut special gaskets for each fastener.
I also have Comp Pro Magnum rockers. With all due respect to the boys at Engine Masters, there's a reason why GM has gone to a full roller fulcrum on their production rockers. Anyplace you can reduce friction is a good idea. That includes the tip as well.
As for clearance the cast cover had plenty of room except at the baffles. Needed to do some trimming there. The OEM stamped cover (which I had on my Vortecs at one point and nicely painted black) required the support bridge to be trimmed but the amount is minimal.
Don't they use shaft mounted rockers, though? Not sure if that makes any difference. I'm unfamiliar with LS motors.
At any rate, I'm sure they use it for a reliability standpoint. There may be less valve stem wear, and they're probably more stable at upper RPMs.
All of that said, and no disrespect intended, the dyno doesn't lie. To disbelieve the video evidence of the dyno runs suggests that you believe they're fudging the numbers. If that's the case, why wouldn't they fudge the numbers the other way to illicit more sponsorship\money?
While I think Engine masters has some good points, discussion etc, I couldn't disagree more. Anytime you can reduce friction in the valve terrain is a huge plus. While I dont claim to be a "Master" I do know a few. And well, Ill keep from repeating their comments about this show. OBVIOUSLY the 1.6rr was going to show the highest results on the dyno. Shocking. The thing that gets me with this show is its just a big flashy, "look at this" and not at other crucial topics. They didnt even mention rocker geometry. Tho I know the topic was rockers. Also, its how they try to get younger generations with the dyno vids and curves. So the rocker lasted for 1 dyno pull. Big deal. Drain all the oil out and Im sure it woulda lasted 1 pull. Lets talk about thousands of miles. IDk, again, I also mean no disrespect but I'd like to see other "fancy" tools used. Like harmonics, or even a heat gun to see the different temps, a camera that will show the deflection. Anyone notice how much more oil was being thrown around when they went to rockers.... I guess what I'm saying is I'm not biting. No, the results dont lie, there are just way more reasons to go to a roller set-up than what they covered. But personally on a mild build engine, I think stamped would be fine.
Just curious how did you set cam endplay with the button.
It doesn’t look like there is a hole in the cover to use a dial indicator.
With the factory roller you can use a cam plate in the front of the block. I don’t think the retrofit cam allows for this it doesn’t have the correct step machines into it.
Just curious how did you set cam endplay with the button.
It doesn’t look like there is a hole in the cover to use a dial indicator.
With the factory roller you can use a cam plate in the front of the block. I don’t think the retrofit cam allows for this it doesn’t have the correct step machines into it.
The block was originally equipped with a roller cam. So I think we're ok. But I've been wrong before and fairly often.
Roller fulcrums make more of a difference on higher spring pressures and higher rpms.
Gm went that way because they also did stand mounted rockers. Cant use stands without a rollerized center. Gm did this Probably for several reasons including long term life, increased valvetrain stability, reduced friction, and ease of assembly/maintenance
Just curious how did you set cam endplay with the button.
It doesn’t look like there is a hole in the cover to use a dial indicator.
With the factory roller you can use a cam plate in the front of the block. I don’t think the retrofit cam allows for this it doesn’t have the correct step machines into it.
The LS rocker is "sorta" shaft mount. It is NOT "stud mount" like the old SBC.
The trunnion fits into a guide object, a kind of cradle, that positively orients it. It has a bolt going down through it that assures that the trunnion stays in the cradle, ABSOLUTELY POSITIVELY oriented, within a very small tolerance.
So in that respect, it's like a shaft mount, where the trunnion is fixed in place and acts as the guide, even though what you see from the view in that pic, doesn't look very much like a "shaft".
But more to the point...
The Engine Masters Challenge is ONLY about max power output under a carefully defined set of rules. It isn't about longevity, maintainability, reliability, consistency, ... it's MAX POWER over some short duration of dyno pulls, is all. And just like racers as alot of them are, those guys are MASTERS at maximizing things that affect the outcome under the rules they are given, while minimizing things that don't. Which is to say, if YOU are playing under different rules than theirs, their decisions may not apply particularly well to YOUR situation. Which is NOT to say that what they do is useless, or they don't know what they're doing, or it's BS, or I know better than they do, or ANYTHING OF THE KIND; only, that what they do, is not necessarily "The Best" for ALL scenarios.
I would not use stock SBC stamped sheet-rubber rockers in any motor I build expecting anything beyond totally original behavior. With all the inconsistencies (i.e. 2 supposedly identical cars that are WORLDS APART in their performance) and failure modes that go along with that. Stock SBC rockers are GARBAGE.
Tuned, you just put a dial indicator on the side of a lobe, and stick a screwdriver or something down into an oil hole or lifter bore (I'd use something non-metallic if I was using a lifter bore), and pry the cam back and forth, to measure the end play. It's not super critical; as long as there's "some" but not "too much", it's good. I'd put reasonable tolerances as .005" - .020" or some such, with being toward the low end as better. .008" - .012" is probably about ideal.
Last edited by sofakingdom; Feb 1, 2018 at 09:03 PM.
I don't disagree, Sofa. I wouldn't use stock ones either. That doesn't mean that ALL stamped steel rockers are bad, though. Aftermarket ones for around $100 will be consistent and won't deflect like a limp noodle. On a mild build (ie, <=1hp:1ci and under 6000 RPM) I don't see any compelling reason to not run them.
I don't disagree, Sofa. I wouldn't use stock ones either. That doesn't mean that ALL stamped steel rockers are bad, though. Aftermarket ones for around $100 will be consistent and won't deflect like a limp noodle. On a mild build (ie, <=1hp:1ci and under 6000 RPM) I don't see any compelling reason to not run them.
I agree. Plus no needle bearings to come loose and possibly do major damage to the engine.
I received a new tool today. To help in checking pushrod length. I have an adjustable pushrod and a set of checking springs. I'll be doing the process where you mark the top of the valve stem and then rotate the engine and look for the contact patch. I thought this tool would give me a second check and get me close before I do the more complicated method.
I have little faith in the tool posted but to each his own.
Remember that when using a "witness mark" method for checking geometry, it's the width of the contact patch that you looking for. The narrowest sweep is one that indicates the correct geometry.
(And the mid lift method is not complicated. In fact it's easier).
No intention to use just the tool. The main goal is building the engine, the secondary goal is learning new things. So I'm studying the different methods out there and hope to get it right and understand why as well.
If you haven't already, the link in post #81 is an excellent read. It's a little wordy at the start as Miller goes into the history of valve train geometry and the development of the first Harland Sharp rocker.
The tech details at the end are what will give a real insight into what's going on.
I remember reading that post last year and getting fairly confused. I think I have a better handle on the subject now and would like to reread. So I went back to #81 but the link isn't working. Do you have another link to it?
I think that once you read Miller's paper, you'll have a handle on it.
The short story: Geometry is checked with the springs you're going to run, the valve on the base circle of the cam and the rocker sitting in position. ( It doesn't need to be preloaded, just placed ). Measurements are taken at the appropriate spots and compared to the net lift at the valve. Push rod length is adjusted to achieve the desired value. It is not necessary to rotate the crank.
This method will ensure that the narrowest sweep on the valve tip is achieved and that is the ultimate goal of having the correct valve train geometry (VGT).
It's position on the valve is of secondary importance however it isn't to be ignored.
If you're interested I have a few pictures of the prototype tooling that I cobbled together and illustrations of the steps taken.
Good to be back, it has been awhile! We made a little bit of progress this holiday season due to a lot less family gathering thanks to the Rona! Anyway, here are some updated photos of what we got done.
We still need to order new pushrods because the "old" ones have mated with the old rockers so the valve covers are just one for sealing purposes. Anyway, about the pushrods... We did all the messing around with an adjustable pushrods and low and behold we pretty much found that the 7.2 original length (for this engine) pushrod was the most ideal with our set up to achieve optimal valve geometry. Does this seem strange to anyone considering we upgraded both the lifters and the rockers were (Hydraulic roller lifters and roller rockers)?
Hopefully we can keep a more steady stream of content coming to this thread. Both my Dad and I have been fairly busy over the last damn near couple years since we posted here! We are working through a lot of questions about the eventual install of this engine and how that will look with a serpentine upgrade, fuel lines, new components into an old system, etc... As always we are looking for any advice and any help y'all can give us.
Welcome back!
Could very well that the 7.2" length is what you need. If you're satisfied that the geometry is good, then that's all that matters. Curious is to what method you used though.
I trust that the valve hadn't been set in the 2nd picture posted. The polylocks look quite out of adjustment.
That is correct Skinny, everything was just put on finger tight to get the rockers in and sealed under the valve covers. The only one that we did set was the nearest one in that picture, however we just set that one with the very popular valve stem wear pattern method you can find on YouTube (tighten until not pushrod movement, add quarter to half turn for lashing, set the polylock, and check dry erase mark on stem for wear pattern after some rotations). We wanted to see how similar the eventual pushrod length would end up being between that method and the much more detailed method delineated in Jim Miller's VTG article. A couple questions about the method described in that article though:
From a theoretical standpoint, I understand most of what he is saying and why this is important. I think he summed it up best when he said;
"Rocker arms are a “radial” device being ordered to do a “linear” thing. They rotate on an axis, moving in a circle. But what they have to impart is a straight line command. They get their order from the camshaft, in the form of IN-LINE information that they then have to ROTATE around an axis and then MULTIPLY it by some ratio, and finally TRANSFER this result back to another IN-LINE component of greater movement. This movement has THREE values: LIFT, DURATION (of lift), and VELOCITY (acceleration of lift). If the rocker arm does ANYTHING ELSE besides this, then it is NOT efficient, and SOME of this information is being lost."
I like his method and it may take a lot more time but I think it will be worth it to ensure accuracy to the cam. Here's my issue, are we going to have to do that for all 16 rockers? Or is there some way to do it once and then set the rest of the rockers to same "setting"? The cam we have has equal lift for intake and exhaust so they all should be the same. My immediate thought would be to measure the distance from the bottom of the rocker stud to the bottom of the rocker trunnion on the rocker that we set via the Miller VTG method and then replicate that across the board. The issue then is that I am assuming some level on uniformity across the rocker side of the head that might not be there, and when you care about a .020 that's a significant assumption to make.
My pops thinks we need to do all of Miller method once, using the push rod length checker, to get the final official required push rod length. once we have that we get those pushrods, drop them in and then set the all the rockers via the simple wear method described earlier because the pushrods are all the same length and as long as each rod is done on base round, the geometry will align with what was desired. Is that an over simplification? Or am I just nuking the subject?
As always, any advice is appreciated!
P.S. here is an image from that article that we can reference for terminology so we are all working off the same script.
Once you have the measurement planes and roller axis' determined, it's just a question of making those measurements and comparing that to your cam lift. One cylinder is all it takes (both valves is my preference). Once you have the correct pushrod length for the one cylinder, you can use that for the rest. With the pushrods in place, the amount of lifter preload you use will determine how far down the stud you twist the polylocks. You'll find that the setscrew in the polylock will all end up in about the same spot relative to the threads available for engagement. Then you're good to go across the board.
The mid-lift method doesn't take into account the preload on the lifter after adjustment. Remember, that using Miller's method doesn't require the nut to even be installed. That can be calculated based on the thread pitch of your particular rocker stud and how far you spin the lock down the polylock. The spring you use for running can be set in place and the rocker arm is just located via the stud with the valve tip and adjustable pushrod supporting either end. Zero preload.
The end result here is that you determine the pushrod length with the adjustable pushrod and the valve train is slack. Then add the amount the pushrod cup in the lifter gets pushed down with the required pre-load. As an example, on a 3/8"-24 stud, one turn of preload equals 1/24th of an inch. Or about .040". It's not much but could be a tipping between one length and another considering we're talking about tenths here.
There's a small risk of error if checking springs are used rather than the running springs. At our power potential (such as what can achieved with Vortec heads however cleverly painted silver) this error doesn't amount to much. But worth keeping in mind.
I built a crude but effective jig for my measurements. Not having a flat retainer top to use a reference complicated matters.
After measuring, I ran a couple of sweeps with some dye on the valve tip. This confirmed the width of the sweep as well as placement.
The old school caliper was fitted under the retainer and provided a flat reference to measure from. The curved shape of the top side of the retainer prevented a conventional approach. If you have flat topped retainers then that can used as reference.
An Allen key (of known size) was used across the retainer reference to a point that equalled the axis of the trunnion. The camera optics show the axis just slightly above the key. Measurement one.
You can see here how the curved profile of the top of the retainer doesn't allow easy measurements. If the retainer is flat you can forgo this goofy setup I cobbled up.
Then, that same retainer reference was used to measure to the roller tip axis.
Adjust the pushrod until the mid lift value is satisfied. In this case it's the thickness of the Allen key subtracted from the .550" indicated on the Vernier.
As a follow up, I also run a sweep with the pushrod at varying lengths. +/- 1/10 one way or the other from my calculated optimum.
7.3". Towards the intake side slightly.
7.4". Better centred and the width decreased from the previous shorter pushrod.
7.5". Advancing towards the exhaust side. Also the width has increased from the calculated 7.4" optimum of the previous picture..
Last edited by skinny z; Dec 27, 2020 at 06:34 PM.
If any readers of this thread are wondering what the heck we've been doing in the long time since this thread was active.... My son (Hammer's Bird) is in the Marines where he is now a pilot flying the MV-22 Osprey. So his time at home has been, shall we say, limited. We wind up doing a lot of long distance discussions about the car. We sometimes connect by FaceTime with me being the hands and him being the brains to work on the car. We created a parts and project list while he was home on leave and our hope is to keep the project moving forward. I'm struggling to keep up with the conversation between him and SkinnyZ on valve train geometry. My head hurts, but I'm making progress. We would never been as far as we are without the help offered by ThirdGen members. So thanks for bearing with us.
LOL 
