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There has just been one thing that no matter how much I try and make sense of it, it doesn't make sense. We used Johnson ST2126LSR lifters in it and the shop that built the engine originally said they used 7.550" pushrods. I didn't get the data I was looking for and second guessed a couple things so I brought it to another shop who I trust very much and they looked it over, remeasured(7.550" again) and put it on the Dyno again. Made great power and had no hiccups. Obviously the pushrods aren't too long and holding the valves open, that's for certain. I doubt they're too short since it makes no obvious noise that's abnormal but I've talked to a couple people, including Tony and he says no way they all take the same length and on top of it they're too short from the norm. 7.600-7.700.
Am I just over thinking it? Should I be looking for anything in particular to see if it's wrong? One thing I thought was interesting is the second shop measured the plunger travel and he said it was close to .100 which isn't right. I'm thinking maybe they were swapped out for 2116s at the machine shop which wouldn't be the end of the world but it would **** me off.
I would go buy a pushrod length checker and do it yourself. I trust hardly no one anymore shop, famous or not these days. It's so easy to just pass the buck on a good running motor and say "it's fine". Question, do you have the adj or non-adj rockers? I am guessing non-adj by the way the conversation has been.
I would go buy a pushrod length checker and do it yourself. I trust hardly no one anymore shop, famous or not these days. It's so easy to just pass the buck on a good running motor and say "it's fine". Question, do you have the adj or non-adj rockers? I am guessing non-adj by the way the conversation has been.
The rockers are non-adjustable, I didn't see any shims so it's not like the stands are shimmed to the same heights either. I honestly don't want to tear into a good running engine but at the same time how is this engine the only short travel engine out there with the same pushrod lengths and no shims? Lol. It didn't make any excessive noise or anything on the Dyno either.
Well I haven't had much time to do anything lately. Went on a giant road trip in by buddy's 64 Rambler with a 5.3 swap that ended up at LSfest. Before ripping everything apart, I figured I would check the wipe pattern thinking maybe it runs well but it could be off to one side. Here's what I got, pattern is about .80-.90 wide.
Upon further research, it appears there are NO shims under any of the rocker pedestals at all. From my understanding the YTs come with .062 shims. I grabbed a couple 3/8 washers from work that measured .056 and put them in, obviously the pushrods are a bit too short now but I turned it over slowly and got what looks like a much better wipe. It's centered better and much narrower than before. I sent a email to YT to see if they will sell me a package of shims.
FYI, I had .120 Shims made for my YT Rockers for my application on AFR heads...
I spent over $50 on various washers trying to find the right size and thickness only to determine that 2 of the YT shims got me the closest. That's when I decided to take some left over 4130 plate I had and have the washers made.
Tony Mamo might have some OEM YT shims. He is a YT dealer.
Upon further research, it appears there are NO shims under any of the rocker pedestals at all. From my understanding the YTs come with .062 shims. I grabbed a couple 3/8 washers from work that measured .056 and put them in, obviously the pushrods are a bit too short now but I turned it over slowly and got what looks like a much better wipe. It's centered better and much narrower than before. I sent a email to YT to see if they will sell me a package of shims.
This wipe pattern is nice. How thin the pattern is is more important than the location of the pattern. Meaning…if the pattern is nice and thin, but a tad high or even a taaaad low is ok. Thinner is better. Obviously centered and thin is best, but not as important simply thin and slightly offset.
FYI, I had .120 Shims made for my YT Rockers for my application on AFR heads...
I spent over $50 on various washers trying to find the right size and thickness only to determine that 2 of the YT shims got me the closest. That's when I decided to take some left over 4130 plate I had and have the washers made.
Tony Mamo might have some OEM YT shims. He is a YT dealer.
I found that Wilwood Brakes has the best solution for hardened shims. Yes, their shims for spacing brake calipers. They have a lot of choices of thicknesses. Perfect for setting up Yella Terra style rockers. Check Summits website. I buy them through Summit and get them in two days.
I found that Wilwood Brakes has the best solution for hardened shims. Yes, their shims for spacing brake calipers. They have a lot of choices of thicknesses. Perfect for setting up Yella Terra style rockers. Check Summits website. I buy them through Summit and get them in two days.
2 days... that's like for ever.... LOL
Brake shims from Wilwood, I didn't think about that. Good thought. I used some various ARP washers and then I order some stuff from McMaster Carr. But even they advertised thickness range was not correct.
I am and was very fortunate to have access to alot off machine tool's at my previous employer. We made my spacers with some left over 4130 plate I had from my project cars... Since I work on stuff at night after hours, I was able to make them the next day and test everything out that night. Still have to wait on Manton though when I order custom lengths...
In my case for my application .120 worked out best. I may be over thinking/ over analyzing this, but I wanted to minimize any chance for fretting or movement at the base of the rockers. there is alot of harmonics and I was concerned it may end up like what happens on main caps when they start walking around. I am sure I don't have tell you, but that's where my mind set was. Personally I would rather have new stands made to the correct length... but having them made and coated can be time consuming...
1. by minimising the sweep you set the geometry at midlift-square. you get the highest lift out of the cam. the difference however is marginal. by having a wider pattern you get better wear, if it matters. there is a simple, direct method of setting up middilt-square, btw.
2. setting the pattern exactly in the middle is not really optimal. the highest valve tip force occurs approx. 30° after open at high rpm. (accleration, jerk and jounce of cam lobe are highest.) so that point should be in the center.
Well it took me a long while, dealing with personal stuff, getting locked out of my google accounts and not being able to access anything. etc. but I have finally gotten around to finishing this long project. I ended up measuring all 16 pushrods and ended up with a pretty narrow spread. Probably why there was no issue with the pushrods all being the same size before. I did add .062 shims to get a better wipe pattern and ended up with (5) 7.611 and (11) 7.616 pushrods. I contacted Tony Mamo and had them on my doorstep from Manton in only a couple days. 11/32 .120 wall.
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Pushrod Length (yes another one) 
