So after picking up a set of 205 11r heads with the 2.080 valves I'm starting to become concerned about potential ptv clearance issues due to the fact im running an inline valve design from Kb. From what I've read the issue comes with the intake valve being in a different position thus completely missing the stock location valve relief. Im going to be going with a custom cam but with a displacement of 357 cubes and a goal over over 400 whp im expecting cam specs to be a bit more aggressive. anyone running flat tops or inline valve pistons with these heads paired with a healthy cam and still maintain good PTV? particularly with the 2.080 valve
11r 2.080 valve ptv anyone?
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It’s kind of a crapshoot. You could have decent ptv, but radial clearance could be small with the 2.08 valve.
I know there have been people who get away with the 11r With inline valve reliefs, it’s been done. If you’re doing heads, it wouldn’t be all that much more work to do a proper tw piston though. Sucks, but it’ll open up more options for you. I think probe still offers the piston that has valve reliefs cut for tw and inline valves. Kinda opens up a can of worms though
I know there have been people who get away with the 11r With inline valve reliefs, it’s been done. If you’re doing heads, it wouldn’t be all that much more work to do a proper tw piston though. Sucks, but it’ll open up more options for you. I think probe still offers the piston that has valve reliefs cut for tw and inline valves. Kinda opens up a can of worms though
I sadly got the pistons before the heads. I ended up finding them for a good deal and took a chance, hopefully doesn't bite me in the ass when its all mocked up.
When you’re mocking up, make sure you check radial clearance with some clay. That’s probably the only part I’d be concerned about. I know Ed Curtis has done cams for guys running Inline pistons with tw heads. I’d get with him about getting a cam done that should work around that setup.
I plan on a cam from him or woody, I sent ed an email but im waiting on a response!
Sending Ed an email asking questions is usually pointless, you have to fill out the info sheet and he will respond, I have talked to him in the past and he gets 50 or more emails a day and cannot answer them and get work done, he is one of the best in the business along with Woody and a few others, sadly I cannot alert him for some reason,
@EDC
Or maybe I can
@EDC
Or maybe I can
Nothing against Ed at all! I’ve seen nothing but positive stuff from his customers and when I have been in contact with him he’s been a really awesome guy about everything. Last email I sent I just asked for a recommendation of which cam core to go with along with my completed build sheet. I’m hoping by the end of next week he will have responded and I can finally get things rollingSending Ed an email asking questions is usually pointless, you have to fill out the info sheet and he will respond, I have talked to him in the past and he gets 50 or more emails a day and cannot answer them and get work done, he is one of the best in the business along with Woody and a few others, sadly I cannot alert him for some reason,
@EDC
Or maybe I can
I have 190 11r on my 347 with JE pistons with inline pockets. Just like you my short block was together and I found the heads at a great deal i couldn't pass up.
I had Ed grind me a cam off all my specs and P to V was .075 on the intake. You will find that your intake valve will contact the piston a good bit above the inline pocket so radial will most like not even be an issue. The exhaust on the other hand fell in the pocket and i had a ton it was around .265
One of the things that will play a big part of clearance issues will be how fast your intake ramp is on the cam because the valve chases the piston.
Talk to Ed he should be able to work with you. The only thing is you might end up giving up some slight performace due to the the box your are trying to work in.
I had Ed grind me a cam off all my specs and P to V was .075 on the intake. You will find that your intake valve will contact the piston a good bit above the inline pocket so radial will most like not even be an issue. The exhaust on the other hand fell in the pocket and i had a ton it was around .265
One of the things that will play a big part of clearance issues will be how fast your intake ramp is on the cam because the valve chases the piston.
Talk to Ed he should be able to work with you. The only thing is you might end up giving up some slight performace due to the the box your are trying to work in.
I think I’m going to have reliefs cut into the pistons just to be safe. I brought this idea up to Ed I’m just waiting on a reply
Hopefully all that’s needed is minimal radial clearance. It’s a standard kB hyper flat top piston
I had the same fit with TFS170s and stock short block. I had ed grind a cam for me. The exhaust valve lined up perfectly with the valve relieve but there was a ton of clearance. Intake valve was above the relief so no issue radially, but PTV was 0.075”. I sent it.
Cam was .565” lift on the intake and 214 duration. I’m sure I gave up a little bit of performance to make it work but for my build it didn’t matter
OldManRiver
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11R 190's with stock '86 bottom end(true flat tops) I'm even closer,.050 with checker springs .065 with the actual Pac springs.
My Lunati cam opens the intake at 4 deg BTDC then chases,opening any sooner would've been an issue.Like Mike .265 on the exhaust.
Only had back on the road for a few weeks but made a few pulls to 5800 without issue.......
Thought about adding valve reliefs or at the very least a .010-.020 thicker head gasket but in the end decided to send it.With the proper spring and modern spring tech I wasn't too concerned with 1/16 clearance.If it grenaded I figured it's only money,I'll make more tomorrow.
My Lunati cam opens the intake at 4 deg BTDC then chases,opening any sooner would've been an issue.Like Mike .265 on the exhaust.
Only had back on the road for a few weeks but made a few pulls to 5800 without issue.......
Thought about adding valve reliefs or at the very least a .010-.020 thicker head gasket but in the end decided to send it.With the proper spring and modern spring tech I wasn't too concerned with 1/16 clearance.If it grenaded I figured it's only money,I'll make more tomorrow.
Yeah, no way for me to really say either way. Each combo is different and all those differences add up. Thickness of the head gaskets, pushrod length, cam specs, rocker arms, pistons, quench, etc.
You can ballpark it, but really you need to clay it.
You can ballpark it, but really you need to clay it.
Had ed grind me a cam with 230 and 240 @ 50 intake and exhaust with over 600 lift with a flat top piston had over .250 on the intake side
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