FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: ksquared on April 26, 2020, 10:48:19 PM
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I'm stopped on my 428 engine build with a problem. The valves are too big for the piston notches. Way too big as my picture shows. I marked the piston top for the valve center and then set a divider to the radius of the valves. I hope you can see just how much of a problem I have. The intake valves are 2.2" and the exhausts are 1.712". Pistons are good old TRW forged from the 70's? This is a bit beyond my experience. I understand about cutting larger notches & I'm aware of the Isky tool. But this seems like lot. And the scratch arcs are the valve edges, not the extra clearance needed around the valves. It almost looks like I'd have to notch the cylinder around the intake valve. :o Suggestions?
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I think the valve notches should be on the top of the piston.
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I'm stopped on my 428 engine build with a problem. The valves are too big for the piston notches. Way too big as my picture shows. I marked the piston top for the valve center and then set a divider to the radius of the valves. I hope you can see just how much of a problem I have. The intake valves are 2.2" and the exhausts are 1.712". Pistons are good old TRW forged from the 70's? This is a bit beyond my experience. I understand about cutting larger notches & I'm aware of the Isky tool. But this seems like lot. And the scratch arcs are the valve edges, not the extra clearance needed around the valves. It almost looks like I'd have to notch the cylinder around the intake valve. :o Suggestions?
Certainly plausible. Here are a set of custom Diamond pistons for a 4.350" bore FE using TFS heads that have 2.190"/1.625" valves. You can see how far up the valve reliefs go.
(https://live.staticflickr.com/65535/49756305156_844ac43e2a_c.jpg)
You're working with a much smaller bore and pistons that were never intended to see anything larger than a 2.090" valve.
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Here are some Racetec pistons for a 428 build. The reliefs are symmetrical, but you can see their size.
(https://live.staticflickr.com/65535/48923484186_9b7e38a87c_c.jpg)
Recognize that if the valve were flat against the face of the piston, you would need to cut the whole circle out of the piston, but valves come in at an angle towards the piston. You will not need to do anything to the cylinders as the valve relief will only see the leading edge of the valve coming in.
The way you have marked the outline is correct. Center punch the centerline of the valve, then swing your arc around.
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Since the valves closest proximity to the piston occurs one side or the other of TDC would it not be best to establish the valve centerline reletive to the piston at that closest point?
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It could be that your picture is deceiving, but it doesn't look to me like your punch marks for the valve centers are in the correct place. They don't appear to be at the center of the valve reliefs that are already in the pistons. How did you mark the center?
Also, what heads are you using? If you are using stock 428 heads, with 2.000" valve spacing, you will have less of an issue with clearance to the cylinder wall than if you used Edelbrock heads (2.050" spacing) or 427 heads (2.100" spacing).
One other thing I just noticed is that even with the stock 2.09" valves, using your marks the valves would still hit the piston tops. I'm pretty sure you marked the center in the wrong place, or at least used the wrong radius to make your scribe mark. Difference in radius between your valves and stock valves is only about 0.050".
Edited to correct the valve spacing dimensions - Jay
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The heads are FElony. The tool used to find the valve centers is an old valve modified. See picture. Brent, I did exactly what you suggested. The arcs are what I got. Jay, I don't see how I could have made any errors. The "punch" was in the valve guide and the head bolted to the block. I will admit that just because I can't see an error doesn't mean one wasn't made. ;) Assuming my method is correct, it looks like I have two options: BIGGER notches or different pistons. I do have the original iron CJ heads but you know how it is when you want mo'power. ;D This is the only thing holding up my engine build. This kind of machine work is beyond my ability at home. I suppose I could take the engine to a machinist but this looks like an involved/expensive task whit no assurance that such a big cut won't compromise the pistons.
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Good idea making a punch out of an old valve stem.... Crazy question.... Do you have the head dowels in place?
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Try scribing a line using a 1.045" radius. That would be the same as a stock valve. If you miss the valve relief with that, then a stock valve won't fit, and that means there is something wrong with your method, because those pistons should work if they are 428 pistons. They look just like a set I used to have.
Using the modified valve as a punch is the right way to center mark the relief. Also you might check with Barry to find out what the valve spacing is on his heads.
You could also try using the same method with your 428CJ heads, and see where the mark ends up...
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Yes the dowels are in place. You are right about the original heads. I'll try them. Will be interesting. I'll also try the 1.045" radius. Just thinking... if the valves are at different locations in the chamber, maybe the 2.09 valves wouldn't clear either. I thought I read somewhere that the FElony heads have different (wider) valve positions so that the larger valve will fit. I might have imagined that. I'll check with Barry.
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It could be that your picture is deceiving, but it doesn't look to me like your punch marks for the valve centers are in the correct place. They don't appear to be at the center of the valve reliefs that are already in the pistons. How did you mark the center?
Also, what heads are you using? If you are using stock 428 heads, with 2.100" valve spacing, you will have less of an issue with clearance to the cylinder wall than if you used Edelbrock heads (2.150" spacing) or 427 heads (2.200" spacing).
One other thing I just noticed is that even with the stock 2.09" valves, using your marks the valves would still hit the piston tops. I'm pretty sure you marked the center in the wrong place, or at least used the wrong radius to make your scribe mark. Difference in radius between your valves and stock valves is only about 0.050".
By memory, the OEM STD LR/CJ valve spacing is 1.990", Edelbrock is at 2.045" and 427 OEM at 2.100".
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Oops, you are correct, I was off by a tenth. Actually I have measured 2.00" for standard FE, 2.05" for Edelbrock, and 2.100" for 427. So much for trusting my memory ::)
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Something doesn't look quite right, but I've never had a pair of Felony heads.
I'd put some checking springs, I use stock rocker arm spacer springs, on #1 cylinder. Then I'd put the piston on #1 at tdc. Put some clay, silly putty, play dough on the valve reliefs of the piston. At the very least, put some wheel bearing grease on the edge of the valve...anything that'll leave a trace. Set the cylinder head on the block without a head gasket. Then gently push the valves down until they hit the piston.
Remove the cylinder head and see where the valves actually touch the piston. I'm all for math and geometry, but sometimes it's just easier to see where things are by actually putting them in the environment where they are going to live.
I have the exact same piston in my Frankenstein 428. With C3AE-D low riser heads and 2.09/1.65 valves they clear fine. Realizing the aftermarket FE heads all have different than Ford spacing and valve sizes, who knows until you check.
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Thanks all. Will check tonight. At work now... As for the clay method, I saw no point as the valves hit the pistons with heads in place with gaskets using check springs.
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Tommy, I think I'll try what you suggest just to confirm my "analysis". Maybe a little dykem blue might help ;)
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Cool!
Post some pics of what you find. I'm curious now!
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Did you have the valve att TDC when you punched?
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You mean the piston? Yep TDC.
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The method I have learned is to first have a good degree wheel mounted to the crankshaft and then indicate TDC for the cylinder/piston being tested. Rotate the crankshaft to 10 degrees BTDC and lightly punch the exhaust side. Continuing to the intake side, rotate the crankshaft to 10 degrees ATDC, and lightly punch the intake side. This is the point at which the valves are generally at their closest point to the piston. Then, simply use these marks as center-points and scribe out the valve OD.
Another thing to check , in some applications, is that the valve relief is cut at the same angle as the valve angle. Sometimes the relief needs to be corrected.
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I had another look at the poster's piston, and I agree with Tom Gahman. The pierce points look to be on the wrong side of the piston centerline?
Edit: I performed a quick and dirty mockup with my own piston and head here and it appears that all is not well. Man, those TRW's had an odd relief placement though, didn't they? It was quite similar on my FelPro 2291's. I did not have to relieve much in my case as there was a mile of room to the valves vertically. If I remember correctly, only the exhaust side needed to be moved a bit.
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Well I guess I earned the Dumb Ass award. :-[ I had the pistons in the block upside down. I can't believe I did that. Tom Gahman you were right. I won't make that mistake again (this month). And yes when I flipped the piston, I reversed the rods. Things now look a little better and now I can get down to checking real valve relief. Once that's done, it's clean up and assembly time. Sorry to waste everyone's time. FWIW I measured the valve centers on the FElony heads at 2.2125" and the factory CJ's at 2.1825. Only .030 difference. The iron heads weigh 97.5lbs and the FElony heads are 56lbs for the pair. With all of the aluminum I'm using, I've saved 129lbs on the long block. If anyone is interested, I have a spreadsheet of stock vs diet parts weights.
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Ha, I just thought the picture was taken upside down.
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So, I have built a bunch of FEs but still say the same thing with each piston. "Eyes right"
As a military guy, it's a term you use when you are doing a military parade, the formation commander says "eyes right", everyone looks at the podium and at the same time, the commander salutes the senior officiating.
The reason this rambling makes sense, is if you install your piston with it looking like "eyes" on top, and verify the rod chamfer on the right as you slip it down the hole, you can't mess up. Needless to say the valve relief location is apparent, but it also helps you make sure you didn't accidentally put a rod on backwards.
Now, I don't bark it out loud like I used to in formation, but as a habit, I think it to myself with every piston as I hang the rods and double check as I stab the piston :)
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Well I guess I earned the Dumb Ass award. :-[ I had the pistons in the block upside down. I can't believe I did that.
If we started a "brain fart" thread, believe me, there would be a thousand stories along side yours..lol
Mike Finnegan JUST put out his latest Finnegans Garage video yesterday. He proceeded to put an expensive, multi-piece clutch on an engine he's got for his C10 truck. He gets it entirely done before his cameraman asks him how long it's going to take to realize his mistake. It took about 5 seconds for him to realize he forgot to put the mid-plate in. Back apart it came ;D
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yes , I agree with that , I say the only way not to make a mistake , is don't do anything . thanks to all for posting . still learning .
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Valve spacing is identical to Edelbrock.
Not sure what up - but that centerline position looks way off somehow
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I think I have a way to remember which way the pistons go in...
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ksquared,
You aren't the first nor will you be the last to do that. Some real losers RAN the engine with the pistons in that way. Fine if you have a 4.6 or 5.4 Modular Ford V8 because that IS the valve pocket location on them.
The L2245 pistons had a problem with exhaust valve clearance forever. Depth was OK but they "clipped" the outside edge ( toward the cylinder wall) and I had to correct them when I went to a cam with 246*s @ .050.
Randy
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..... If anyone is interested, I have a spreadsheet of stock vs diet parts weights.
I'm interested. Glad you got your situation figured out. 8)
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Hey, it can happen! Long ago, my bro told me a pal had assembled his SBC but could not turn it over. Told him to have the pal take off the heads to see if it turned. Sure enough, it did. On first Gen, SBC's, the valves were e-ii-ee-ii-e. Told to look at the pistons, he had swapped a few pistons onto the wrong rods and didn't have vlave clearance with his new hot cam. Switched around, all was fine.
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FElony, here is a PDF of the spreadsheet I made to record all of the engine parts weights. I have a 4spd top loader I could add if anyone is interested. Measurements were made with a pretty accurate digital scale (+-.5lbs) The forum won't allow me to upload a spreadsheet file. If you want it, email me and I'll send it.
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FElony, here is a PDF of the spreadsheet I made to record all of the engine parts weights. I have a 4spd top loader I could add if anyone is interested. Measurements were made with a pretty accurate digital scale (+-.5lbs) The forum won't allow me to upload a spreadsheet file. If you want it, email me and I'll send it.
I think the .pdf will do just fine. Thanks for the interesting info. I'll look it over more closely tomorrow.
FElony