texas speed prc 237 pushrod limits
Thread Starter
Launching!
Joined: Dec 2011
Posts: 242
Likes: 4
From: Alabama
texas speed prc 237 pushrod limits Setting up my new 237 heads and checking PTV clearance I noticed the intake PR was up against the bore for the rod and at a angle . Got to looking closer and all intake PR bores are all offset . I am sure the size of the intake runners are the reason for this . I planed on running a 11/32 push rod but out of the question now . Planed to set up this valve train the right way with morel lifters and yella terra rockers to stabilize everything . Now I have limits on the push rods ( 5/16) . The heads looks to have plenty room for the LS3 intake offset rockers if the rocker bolt location was drill to that position . This would move the pushrod over closer the the center of the bore and allow for more options on pushrods . Now I am restricted to 5/16 diameter . Talked to Texas speed and no options for ls3 rockers on these heads an was asked why I wanted a 11/32 push rod . ?
This is nothing radical . Will be turning 7000/7200 234/238 629/629 . But I would like to get the most out of my valve train . Just wanted to know your thoughts and let you know what I found .
This is nothing radical . Will be turning 7000/7200 234/238 629/629 . But I would like to get the most out of my valve train . Just wanted to know your thoughts and let you know what I found .
Last edited by homemade87; Dec 22, 2019 at 05:36 AM.
TECH Apprentice
Joined: Oct 2015
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I run the 5/16 stock rockers truion upgrades. 260/270 650 lift. No issues with the valve terrain. Morel 5206's.
Ran 2 seasons this way (over 600 passes). Tore down this year and valves needed a touch up but all else was good. I am no pushrod expert but at 629 I expect you would be fine. And I am at 80 on the preload.
One more thing 7500 every pass.
Ran 2 seasons this way (over 600 passes). Tore down this year and valves needed a touch up but all else was good. I am no pushrod expert but at 629 I expect you would be fine. And I am at 80 on the preload.
One more thing 7500 every pass.
Thread Starter
Launching!
Joined: Dec 2011
Posts: 242
Likes: 4
From: Alabama
Thanks for the reply , I did see where there is a 5/16 pushrod that is .105 wall which will be stiffer that an .080 . This may be a better choice . Just not as stable as the bigger diameter push rod .
Thread Starter
Launching!
Joined: Dec 2011
Posts: 242
Likes: 4
From: Alabama
Are you running the prc237 head as well . Just wanted to see if you seen the same thing as I have .
Thanks cmysix , I will message you as soon as I see what lenght I need .
I do have a picture , not sure if you can tell much . The pr bore on the intake is moved to the left of the rocker bolt hole .The second picture is where the push rod will run at up against the bore slightly .
Last edited by homemade87; Dec 22, 2019 at 08:44 AM.
I'm running Trick Flow "fast as cast" 220's on a stock bottom end LS2, you can see in my sig what cam I'm running and with 3/8's PR's it looks so very close to rubbing, That when I pull the heads to have them milled I'm going back to 5/16 PR's, I guess if I really wanted too when I pull the heads I could have the machine shop enlarge the holes, But I've already got the PR's in the size I need, I appear to have more room to do that then you do? I will go thru the rods to day and let you know what I've got. the 3/8's I have in the motor now are 7.525 long.
Thread Starter
Launching!
Joined: Dec 2011
Posts: 242
Likes: 4
From: Alabama
cmysix , I don't have the luxury of enlarging the holes ( wish I did ) . I have learned there is only about .035 material from the bore to the runner . The reason they offset the bore ( ls3 rockers bolt location would have fixed this ) . I would guess this must not be a problem because I cant be the only one who has these heads . Just cant run the larger diameter rods . I am going to make it work . I do like the heads and is a good fit for my project .
Thanks for the input . I will let you know when the rockers come in and can get them checked .
Thanks for the input . I will let you know when the rockers come in and can get them checked .
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Thread Starter
Launching!
Joined: Dec 2011
Posts: 242
Likes: 4
From: Alabama
Update , Just wanted to reply and report on the status just in case some have read this and are following . After I had time from the holidays I mocked up the other head to check pushrod bore clearance . To my surprise I had more clearance on this head . Not much but in my opinion enough to run it . It had movement left to right when you wiggled the rocker . So I started to figure out why . As it turned out the one head I was checking has a smaller pushrod bore . After calling texas speed they were in disbelief of my finding . They run heads in batches and could not answer why . Texas speed has stepped up so far and sent me a shipping return label even tho they think my finding is wrong . There is no question my finding was correct and said they will ship a new head if this is the case . The good head was .625 which is the correct size and the other head was .585 bore . Does not sound like much but when its that close to begin with makes a big difference .I will still have to run a 5/16 rod . Head is on its way back . Things do happen and wanted to let everyone know texas speed so far is doing the right thing .
Last edited by homemade87; Jan 3, 2020 at 07:43 AM.
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Thread Starter
Launching!
Joined: Dec 2011
Posts: 242
Likes: 4
From: Alabama
Thread Starter
Launching!
Joined: Dec 2011
Posts: 242
Likes: 4
From: Alabama
Another update , After calling my contact at texas speed and they had time to look things over an there findings was the same as mine . All pushrod bores on one head was the wrong size . Not exactly sure what happened to create this problem and I did not push to find out . In my opinion there must have had a improper bit or a worn bit that made the bore to small with the latest run of heads . I must have gotten one from the last run and one from the latest run . But in the end I did not question much knowing they have acknowledged the problem and will correct it . Just waiting on a tracking number as of now . I do not anticipate any problems from here on out . All aftermarket products can have there problems this is why it pays to look at things close .