Anyone using PRC with their bronze guides ? PRC via TSP say they are fine with factory rockers.
im still doubtful and wanna hear success / failure stories.

Ive emailed the pros and gotten tbeee responses.

Derick at TSP “We use a very hard bronze from CHE for our guides so guide wear is not commonly a problem on them in general”

Jacob at Btr says if you putting miles on bronze guidew with factory rockers youll have to change them. (Yes I’ve seen BTR’s new video which I spoke with TSP on the phone about and they basically called it salesmen ship)

Tony Mano says factory rockers have issues with all guides.

Mika at CHE says “ As long as everything is set up correctly, our guides will last just as long if not longer due to their ability to draw more heat out than the OEM guides”

 

This will be interesting, they all had comments that align with the parts they sell or recommend. I hope some machine shop guys chime in with some real world results/measurements. I think the big thing is cars that really get miles on them vs just a track **** that sees some street miles, but nothing major.

I will say I had some nice Pete Incado 243's from the 2005 timeframe on my NA 383 setup that made great power 501/445 whp/wtq (they later made 458/408 stock bottom 227 230 cam on a stock 5.7 bottom) and racked up maybe 10k on the bronze guides. It appeared the guides were changed before I got the car for some reason or they bent the valves as the new ones were not CNC'd with the ports. They were run with stock rockers for some time, but I don't know how they would measure or what brand they were. I was not as experienced in feel of the valve either so hard to say. I've seen some guys like Powell mention that they don't see a lot of wear in the PM guides on the 1.7 rocker lower lift LS stuff.

 

Thank you for the reply. 10k and going strong or 10 and wearing out?

Im hoping to see some of the engine builder machine shop Guys chime in.

I think it goes without saying that I am interested in driving the car in the street for as long as possible w/o needing to pull the heads. I do not believe this is a thing with bronze guides based on what I read. Heck, I’m not convinced the last all that long with roller rockers at this point haha

 

I'm very interested in this topic. I have a single data point to offer for what its worth. My old 6.0 had stock 243 heads with stock guides and valves. I bought them off ebay, supposed to be low miles and they looked very clean when I took out of the box. I removed the stock yellow springs and installed PAC 1218 beehives. Stock 1.7 rockers. The cam was an older COMP cam with .598 lift and aggressive ramp rates. I put about 30k street miles on this setup and about 1,000 1/4 mile passes. At this point all the guides are SMOKED. A LOT of clearance. This engine blew up in the fall of 2024 when a exhaust valve broke off and the piston crashed into it. I missed all the warning signs leading up to this, and there were a lot of warnings.
I don't have any experience with bronze guides, so I can't offer anything there.
My next setup will be, better flowing heads with powdered metal guides and a lower lift cam. I'm willing to leave power on the table with say a .550 lift cam and achieve higher miles. I would rather have great heads and a milder cam because of all the street miles I run.

 

Yup, had similar issue with eBay heads. Never again. TRP machine is trash!

I’m not sure if the valve guide broke or if the spring collapsed. They were said to be PSI springs But the spring on cyl 2 measure about 15% below the rest of the springs and that valve guide was broke. I can only assume the spring was trashed and that lead to the valve guide breaking after the piston made sweet sweet love to the valve and heads

Those heads lasted all of 30 pretty gentle moles. I heard a LOUD bang and then the motor was ticking.

here’s the damage honestly not to bad got super lucky with that guide. Cylinders are fine as is the block

 

Pretty much sums it up! Go with the bronze guides because they're stronger and dissapate heat much faster than the steel and if valve geometry is right good things will follow.

 

Guides is a touchy subject... It all depends on the application.

The biggest issue with the factory guides in the LS heads is no one ever checks them. These engines are now 20+ years old. Especially when buying used. You have no idea how well or poorly the engine was cared for.

The last set of 243's I purchased needed all the exhaust guides and a couple of the intakes replaced. I ended up having them replaced with the SBI hardened steel guides.

My options were.
the SBI hardened steel guides. around $250 parts and labor
or the CHE guides. Around $500 parts and labor

The shop tried to talk me into the CHE guides, but I explained to them it was a street motor and I want the longevity. I don't want to tear the engine down in 20-30K miles. They agreed and the SBI's were installed. It's not a money thing.
I asked them point blank what is the average Life expectancy out of the CHE? I was told most likely around 20-30K And they said I would likely get around 100K out of the steel guides.

I just sent another set out and inquired about the powdered metal guides that BTR has. Looking at the same $500 parts and labor as the CHE option...

 

Both styles are fine, but the PM will just put last a bronze all day. If running bronze, go roller rocker. You need to get the side load off guide and roller is only way to do that. If you do go roller, you need to spring accordingly(more).

 

this lines up with what I am tending to believe

 

yup, trying to understand how much more spring needed is hard. Say 630 cam with rollers I’m guessing .660 spring is on the edges of the limits

 

I am currently running PRC 247s with stock rockers. I was also told by TSP that it would be fine, actually was told 100k miles. Engine just went in. Has about 300 miles on it. So no update anytime soon.

If you look at any PRC Head, they all say "Factory Rocker Friendly" but what does that really mean?

 

It's not the lift, per say, but the weight of the tip of the rocker. Honestly, I think the whole .660 spring deal is a trap. I think a better beehive is way better and if you need more, then go duals(PAC 1207x/08/09). I put my $$$ where my mouth is, my new cnc 243's have PAC 1276 beehives on them w/ tool steel locks/retainers. TurboBuick6 is on here and he works for PAC. Per him, 180# on the seat min, and I would agree with that. If it's a street car, shoot for 190-200# as the spring will settle in. Nobody factors wear in on here. I drive the **** out of anything I own, so I am used to abusing stuff to the limit. FYI, cheater tip, too much distance between coil bind/max lift will cause a bounce issue(on the spring itself) in a high rpm deal, even with great springs. Need to keep the total valve open vs coil bind around .060 or so if you are shooting for max power. Google it, lots of good discussions on YB and Speedtalk about that. Depends on how serious it's going to be.

 

I appreciate your reply. I’ve been opposed by o the .660’s for many reasons. I feel it’s too much pressure, I feel they won’t operate close enough to coil bind as you mention which leads to instability.

TSP and several other manufactures convinced me. Oddly trickflow , TSP, and a few other companies use the same 238/242 595 cam and all of them call for a .660 spring except the cam manufacturer and the spring manufacturer. Elgin and PAC respectively.

I emailed pac and they undersold me saying I did not need the 1219 that the 1218 was enough. Elgin was selling something close to the 1218 slightly lighter actually but did note to give room for RPM and wear as you mentioned too.

the duals springs harmonic more from what I’ve understood and the beehives control harmonics better at High RPM. There’s a slow motion video on the tube. Pretty neat.



It’s hard to get what I as a consumer have come the believe I want / need with professional advise. All the vendors seem to be pushing one ideology as if it’s the only way. Reminds me of politics. They are all mostly just after a sale. A few weeks ago TSP on the phone basically bad mouth BTR calling him a salesmen.

 

A vendor acting like a salesman? No way!! Look at it this way…IF you were to buy a perfect set of springs for the application that lasted for years AND didn’t hurt lobes, rocker pads, cam bearings, lifters, etc…you’d likely outgrow the hobby and move on in life before you needed more parts from that vendor. It would hurt their bottom line. Salesmen are salesmen.
They will never tell you to run the lightest spring package that’s possible to increase BOTH parts life AND spring life. Always purchase your springs as a package from the camshaft manufacturer. They know best. Tony Mamo is one of the few guys I’ve ever talked with that always recommends the lightest spring package for the application. More spring pressure than needed is never a better choice in 99% of applications, and setting up the correct spring to the correct installed height is crucial.

 

Ah yes, ye old Sloppy Stage 3. I always liked the specs on that cam, but wanted more lift. Yeah, beehives for sure on that, look at a PSI 1515ml. Good overall specs for that cam. I got one for you, feel the weight of the box of springs if the beehives vs the duals when you get it. That alone will sell you on a single vs double. I only go double when the cam gets serious and i need the pressure. Fir reference, my PAC 1276's have more rate than a typical . 660 BTR/TSP/etc spring pack at 2/3 the overall weight.

 

Not all of us.....LOL (And it's Tony Mamo OP....not Mano....figure if Im quoted it should be spelled right! )

My response above (which the OP abbreviated well) is dead on and doesnt favor any outcome or sale....in fact the heads I sell come in both configurations. Some have bronze.....some have PM.....both work.

More facts....OEM rockers produce side loading which wears the guides. Their geometry is horrible.....anyone ever check wipe pattern with a stock rocker? What is supposed to be a rectangle is a square....meaning that the arc'ed pad of the OEM rockers scrubs from one side of the valve tip straight to the other imparting side loads that create the guide wear over time you guys are trying to minimize or avoid.

Roller rockers reduce this dramatically as the contact point of the roller is much more narrow and you do get the desired rectangular patch in the center of the valve assuming you set the stand height properly. This geometry improvement drastically reduces sideloading and for the most part, only imparts the intentional vertical forces to open and close the valve.

Note most (almost ALL) of my builds feature roller rockers for this very reason

The higher the lift the further the wear as the pattern of the OEM rocker gets even wider with more lift....thats why Tooley and others try to cap off how much lift is recommended with OEM rockers.

With the proper guide clearance, a PM guide will always outlive a bronze guide. I don't care who makes it or what special sauce they want to tell you is in their guides

Hone a few guides as part of your day job and that's easily seen.....you spend twice as long to hone a couple of tenths out of a PM guide than a bronze guide. Anyone telling you different doesnt know or isn't shooting it to you straight.


What's there to conclude or draw from all of this....help yourself and consider roller tip rockers. A roller rocker triples the service life of your guides so if your concerned about longevity better start giving them some consideration.

If your the type of customer that really racks up the miles (12K+ a year) and you can find a head that will meet your performance needs with PM guides clearly that's the best way to go but consider roller rockers because without them your going to shorten the life of any guide considerably.

Stock engines get away with stock rockers due to really low lift (for a smaller scrub pattern).....really low spring pressure and typically a much lower RPM ceiling. Also note most (possibly all) OEM guides are PM and that's not just a coincidence. The OEM's are always thinking about less warranty work, less lawsuits, and enough longevity to get you past the warranty period at a minimum.

I set up bronze guides a little tighter to get my customers the most life they can from the heads I recommend that comes with them....I also open up the clearances a touch in my PM guide applications because they need a little more oil due to having slightly less lubricity in the actual metal compared to a bronze guide material.

There is probably more I can add but this covers most of the larger bullet points related to this discussion

Hope some of you find this information helpful

-Tony

 

Spot on Tony, as always. Interesting about you opening up PM guide clearance a smidge…a thou and a half is an industry standard. Nothing standard about your stuff, so of course you’re going to tweak this as well. Thank you for your tech and willingness to spread knowledge here.

 

Another thank you for Tony. BTW, our combo is still running really well. Virtually no oil consumption, and tests my 315 wide PS2s regularly. They always fail the damn traction test!!

 

This thread has already had guys chime in with real world measurements. My builds get driven by my customers often and very hard. Tony’s customers absolutely beat the slop out of his stuff. TurboBuick works for PAC springs and sees customer abuse daily. DualQuad is a builder who has guys flogging his stuff. I’m sure others chiming in also here have put some miles on builds with real results.

 

Yeah, like going 20K miles on .660 springs with BR7 heads with bronze guides and T&D steel roller rocker arms. I have a set of 1207x springs to install on the heads and really need to get that done this year. Camshaft is a CamMotion 8620 core ground to 243/251 .661/.633 115+4 and the higher lift spring will be better suited for the heavier steel rocker arms.