Agreed - the main reason to use bolt turn method is to verify what you already have is about right. Which is the question I thought I was answering

 

Using the threads per inch idea doesn't work as it doesn't translate.

But normally 3/4 turn is .050-.060 and half then would be around the .030 area.

Its best to measure with a dial indicator there since everything is so different.

 

When I compared with a dial I got .038 at half turn using an angle gauge.

 

Just to be clear, you are saying stock rockers are fine with the bronze guides in the AFR heads?

 

AFR recommends roller tip rockers with their bronze guides.

 

Also recommended by Tony with his heads, which is why I went with them.

On a side note, had a conversation with a tech at Johnson lifters, they agreed I am too deep into the preload and suggested remeasuring. I will be doing that this weekend. Nothing explains the chirp/squeek that I am experiencing, and inspection of where I hear it shows good rollers on the lifters, and no marks on the cam. I may be pulling a head this weekend as well.

Thanks for all the help thus far.

Jack

 

Hey Jack.

You know why I asked that.....😜
I bought my AFR’s used. I’ve had them on for 20k miles now. Guides are still fine.

I currently have them apart for cleaning and inspection prior to putting them on my new 6.2.

I also have new lifters that require less preload, so am about to go through this setup again shortly. My engine is on the stand though, makes it a bit easier.
Car is the C5 in my .sig.

Ron

 

No. I just meant ditch the alum. Find some steel.

If theese or any AFR use a stock valve angle, then you should not see much accelerated wear on the guides though with a stock style rocker. I know quite a few of their castings have/do use stock valve angle.

Bronze guide materials and design have changed and CHE seems to be at the forefront of that. Really using some older design and style and material would be counterproductive. Now since i assume these are likely years old, maybe guide wear should be checked anyway.

 

My AFR 205's were prepped and delivered by Tony Mamo in Feb of last year. Unfortunately they sat on my shelf until last month. I had to wait a few months for the Ferrera valves to come in, I doubt they are using old materials.

 

I didn't think AFR made 205's anymore, being replaced by 210's a couple years ago.

 

airflowresearch website now shows part number 1510 as a 205 runner instead of the 210 it use to be.

 

Interesting! Maybe the 210 didn't prove itself to expectations, or it just got refined to flow with less material removed

 

Just to clarify for everyone here.....Jack (the OP....babyduece) purchased a Mamo Motorsports product.....my MMS 205's (which are built around AFR castings).

I mostly recommend them for 5.3 liter builds but they could easily be used on 346 builds as well that are focused on huge low and midrange grunt. They come with small valves to allow them to work really well on the small bore 5.3 liter engine that was my target design.

In spite of only having a 1.975 intake valve, they flow a tick under 300 CFM and that is why you could run them on a larger 346 as well and still make really good power with crazy throttle response and big midrange grunt also.

Regarding Jacks preload issues we have shared quite a few emails and with the 2/3 of a turn or so of preload he confirmed he had (assuming he did this testing correctly) I tried to convey to him that his preload is not the issue here. He is on the deeper side of whats OK but it is still OK and once again assuming the information he is conveying to me was/is accurate, the preload is not the root cause of any noise he is experiencing.

My personal CTSV engine.....I had a week to build this engine (long story and a stressful process with $500 in red label everything) and the pushrods I was forced to run with my short travel lifters were all a touch long but that was all I could get quickly. I had 3/4 of a turn preload and some a touch more (that was including the full torque of the bolt so a little less really) which is similar or worse to what Jack had described to me recently so I was comfortable that wasn't the issue he is chasing. The valvetrain in my V is quiet for a performance cam and been running flawlessly in that car since 2012 when I actually built that engine. In fact it has 36000 miles on it since I did the heads cam swap and it has required nothing more than oil changes and a spring swap all this time.

Once again guys don't forget its better to fall on the deeper side of "preload perfection" which Im calling 6 - 7 O'clock.....or a half turn or slightly more, because as soon as the engine gets some heat in it you have less preload than when the engine was cold due to the aluminum block expansion and its significant.....at full operating temp your preload decreases by approximately .010 of an inch.

Hope this post helps to clear up a few things....

-Tony

PS.....I should add that my lightweight aluminum purpose built HR rockers with their narrow centered wipe pattern, no scrubbing or side-loading forces to potentially wear out my guides.....well they have performed flawlessly at 700 RWHP with god knows how many countless blasts to experience that power level during the 36000 miles since they have been in service. I recommend proven parts that I run personally guys and have helped hundreds of other customers with similar very positive results. In fact a handful of you guys reading this have gotten a ride in that car

 

Thanks for chiming in Tony, my apologies , as I did not mean to infer your works of art were standard AFR 205's.

 

OK, that's different. Torque ont he bolt doesn't count toward preload. Once you start torquing, you're not adding preload. You are stretching the bolt slighgtly, which is where the clamping force actually comes from. Basically, you count the rotation just until the bolt bottoms out. You're very likely dead on by that description, since it takes about 1/4 turn to torque the bolt.

I just read his follow up post and realized that rotation included the bolt torque, which would not add to preload. I see where you guys are at now.

 

Jack,

I mainly clarified that because AFR discontinued the 205 a long time ago when the 210 was released but its a very different head (the AFR 205 vs my new MMS 205) in regards to mine is really aimed at a small bore engine. Small bore meaning the 5.3 which was the target audience of my product and thats why Im running valves on both sides that are a good bit smaller than the older AFR design which was aimed at a 346 and a larger 3.900 bore.

The cool thing is Im getting about the same flow with a 1.975 intake valve and a 1.570 exhaust which works alot better with the 5.3 bore size due to less shrouding issues (aka room around the valve).

I knew it was confusing for those reading when you were discussing the 205 product as I haven't done a very good job of advertising my new ones.....LOL

Regards,
Tony

 

Got ya on the steel. This set of YT's for me have been fine......
Trust me i'd rather run a stock rocker setup, just don't want to be a guinea pig if you know what I mean.

The manufacturers just say bronze. Would be nice to know what kind.......more than a few alloys.

And yes, my AFR 205's are old.

 

So jack should have said MMS 205's. There would have been no confusion.
And when I go to the AFR web site, the 210 is not there. just the 205, and their new Enforcer stuff.

My AFR 205's were supposedly rubbed on by you, but I have them apart now, and no visual signs that anyone did any rework. Still a great head, and will work nicely on my new 6.2.

BTW, back in the day I ran your AFR 305's with CNC chambers on my rat motor. 9.90's on pump gas, street car. Wasn't a street car around here that could touch it.

Ron