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Valve Height on 1956 315 Hemi Jump to page : 1 Now viewing page 1 [50 messages per page] | View previous thread :: View next thread |
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dougruffner |
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Veteran Posts: 177 Location: Omaha, NE | Does anyone know the correct assembled valve stem height for 1956 Dodge 315 hemi with solid lifters? It has double springs. Thanks! | ||
Shep |
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Expert Posts: 3393 Location: Chestertown, NY ( near Lake George) | There would be no standard for that as the valve would sit higher after a valve job, but the spring installed height should have a spec and can be set with shims under the spring. | ||
Mopar1 |
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Expert Posts: 3027 Location: N.W. Fla. | All hemis had dual springs. | ||
wayfarer |
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Elite Veteran Posts: 888 Location: Peoples Republic of Oregon | Valve stem height is a moving target. The 'usual' install is for the spring to be 1.2" open and 1.7" on the seat and all tips at the same elevation. Additionally, as noted, shims are often used to adjust for differences in the springs. Do not sink the valve head as this will screw up air flow. Is this a new build? Are the spring rates matched to the cam profile? Is the spring the correct application for the engine? | ||
57chizler |
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Expert Posts: 3768 Location: NorCal | Shep - 2014-10-19 2:17 PM There would be no standard for that as the valve would sit higher after a valve job, Actually, there is a valve height spec but it's not always published and is often shown in the FSM as being checked with a special factory gauge. Valve grinders usually have an attachment on the side of the stone to grind down the tip of the valve stem to correct the installed height. Incorrect installed valve height affects the rocker arm geometry but it's so minor that most folks only concern themselves with the valve spring installed height. | ||
Shep |
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Expert Posts: 3393 Location: Chestertown, NY ( near Lake George) | 57chizler - 2014-10-20 2:53 PM Most of the time the valve tip is resurfaced for finish and true squareness, excessively sinking the valves during a valve job would certainly be bad for geometry, but it would still require some guesswork to correct as there are no valve heights published thru at least 64, I guess we could measure it on an untouched head and valve combo to use a guideline, really don't see the necessity on our engines.Shep - 2014-10-19 2:17 PM There would be no standard for that as the valve would sit higher after a valve job, Actually, there is a valve height spec but it's not always published and is often shown in the FSM as being checked with a special factory gauge. Valve grinders usually have an attachment on the side of the stone to grind down the tip of the valve stem to correct the installed height. Incorrect installed valve height affects the rocker arm geometry but it's so minor that most folks only concern themselves with the valve spring installed height. | ||
57chizler |
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Expert Posts: 3768 Location: NorCal | Anybody who's done a valve job on a flathead with non-adjustable tappets learns the importance of valve length and value of the stem facer attachment on the valve grinder. | ||
Shep |
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Expert Posts: 3393 Location: Chestertown, NY ( near Lake George) | 57chizler - 2014-10-21 1:32 PM Agreed, valve length is an issue on a flathead.Anybody who's done a valve job on a flathead with non-adjustable tappets learns the importance of valve length and value of the stem facer attachment on the valve grinder. | ||
dougruffner |
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Veteran Posts: 177 Location: Omaha, NE | It's a new build. The original combustion chambers had water, so the heads have rust in the cast iron. The machinist was uncomfortable using them. I had a 315 hemi out of a Dodge truck and am using the heads from it. He's going to take the old heads, put the valves and springs back in and take some measurements. The original hemi had been rebuilt once, so I hope the dimensions will be correct. Here's the spec's on the cam I'm using: .290 Lobe Lift 218 Duration @ .050 266 Advertised Duration 109 Lobe Separation .018" valve lash (hot) It's pretty close to a D500-1 cam. Does anyone know if the original springs will work? As long as the springs don't block (bottom), will I be OK? Edited by dougruffner 2014-10-25 5:12 PM | ||
Mopar1 |
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Expert Posts: 3027 Location: N.W. Fla. | dougruffner - 2014-10-25 4:07 PM The cam didn't come with spring specs? depending on how bad the pitting in the chambers is, T R Waters can machine the surface to smooth them out.It's a new build. The original combustion chambers had water, so the heads have rust in the cast iron. The machinist was uncomfortable using them. I had a 315 hemi out of a Dodge truck and am using the heads from it. He's going to take the old heads, put the valves and springs back in and take some measurements. The original hemi had been rebuilt once, so I hope the dimensions will be correct. Here's the spec's on the cam I'm using: .290 Lobe Lift 218 Duration @ .050 266 Advertised Duration 109 Lobe Separation .018" valve lash (hot) It's pretty close to a D500-1 cam. Does anyone know if the original springs will work? As long as the springs don't block (bottom), will I be OK? | ||
dougruffner |
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Veteran Posts: 177 Location: Omaha, NE | The cam is a regrind from Erson Cams that I bought from a guy that rebuilds D500's and D500-1's. I wrote Erson and got the following info which doesn't say anything about spring specs: Doug, No we didn't supply the cams to Dodge in '56 Your cam is just our RV15M grind on a 109 Lobe Separation Bonus Trivia: It was ground on May 7th of 2007 It was ground by our then head grinder Chuck It was a re-grind and it was ground for a company called Tri Valley Machine The specs on it would be: .290 Lobe Lift 218 Duration @ .050 266 Advertised Duration 109 Lobe Separation .018" valve lash (hot) I am not sure what ratio rocker arms are on a 315 Hemi. If I had to guess I would say they are the 1.57-1 intake and 1.52-1 exhaust. This would make your valve lift: .455" Intake .440" Exhaust I have no idea what the specs were on the D500 or D500-1 original cams. Hope this helps Edited by dougruffner 2014-10-25 11:23 PM (2013-10-15 17.24.58 1.jpg) Attachments ---------------- 2013-10-15 17.24.58 1.jpg (98KB - 127 downloads) | ||
Mopar1 |
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Expert Posts: 3027 Location: N.W. Fla. | I'd write them back & ask, where they might not have thought about the springs when answering. | ||
wayfarer |
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Elite Veteran Posts: 888 Location: Peoples Republic of Oregon | That is not a wild grind by any stretch of the imagination. In my shop I'd just use the Mopar #1739534 (360-2v) or #P4286813. 1.38/1.39 OD 1.01/1.02 ID @1.7" installed 97/102 lbs @1.2" installed 202/211 lbs | ||
dougruffner |
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Veteran Posts: 177 Location: Omaha, NE | Is that for a double spring combo? | ||
wayfarer |
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Elite Veteran Posts: 888 Location: Peoples Republic of Oregon | Those are singles. We have used them on many rebuilds...they fit and work very well. Most new double spring sets will have far too much pressure for what you are doing, the exception is, of course, application specific replacements. The usual issue then becomes price. | ||
dougruffner |
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Veteran Posts: 177 Location: Omaha, NE | Do both of these have the same spring force when compressed? I bought new valves that have a different distance from the valve head to the keeper slot. Then, what is the correct stem height so that the rocker arm geometry is correct. Edited by dougruffner 2014-11-02 1:03 PM | ||
Mopar1 |
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Expert Posts: 3027 Location: N.W. Fla. | what is the spring pocket size? | ||
dougruffner |
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Veteran Posts: 177 Location: Omaha, NE | The truck heads are at the shop. Spring pocket on the original D500 heads is about 1.5 inches. What I want to end up with is a valve correctly placed in the seat and head and a spring that fits and has the correct installed spring force. Then I want rocker arms with correct geometry meaning the valve stem height is correct. Then I want the correct spring force when the valve is completely open. The machinist talked about sinking the valves into the seats which I read is not a good thing. Sounds like some mixing and matching of parts and a lot of shop math. Does anyone know what the rocker arm geometry is on a 1956 315 D500 hemi with soild lifters? Edited by dougruffner 2014-11-02 1:49 PM | ||
dougruffner |
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Veteran Posts: 177 Location: Omaha, NE | Rocker arm ratio is 1.5. | ||
wayfarer |
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Elite Veteran Posts: 888 Location: Peoples Republic of Oregon | dougruffner - 2014-11-02 10:46 AM The truck heads are at the shop. Spring pocket on the original D500 heads is about 1.5 inches. What I want to end up with is a valve correctly placed in the seat and head and a spring that fits and has the correct installed spring force. Then I want rocker arms with correct geometry meaning the valve stem height is correct. Then I want the correct spring force when the valve is completely open. The machinist talked about sinking the valves into the seats which I read is not a good thing. Sounds like some mixing and matching of parts and a lot of shop math. Does anyone know what the rocker arm geometry is on a 1956 315 D500 hemi with soild lifters? Please do not look for exact geometry in any engine that costs less that $20k to build...most shops do not care enough to get that involved and the ones that do will charge accordingly... Spring force is easily measured on the bench, assuming that your shop has a spring compression gauge. In the FWIW department, we have measured rocker arm ratios from 1.49 -1.52:1...not exactly 'exact'....but, this is generally only significant for high output engines (back to the high dollar rebuilds). | ||
57chizler |
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Expert Posts: 3768 Location: NorCal | Rocker arm ratio is based on a dimension that changes as the rocker arm swings through its arc. | ||
wayfarer |
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Elite Veteran Posts: 888 Location: Peoples Republic of Oregon | 57chizler - 2014-11-04 10:48 AM Rocker arm ratio is based on a dimension that changes as the rocker arm swings through its arc. The rocker arm ratio is nothing more that the comparison of the length from the shaft centerline to the center if the pushrod tip and then from the centerline to the center of the valve stem pad. Yes, there is some change in the exact location of the contact patch at different valve opening positions but the ratio is not infinite variable..... | ||
dougruffner |
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Veteran Posts: 177 Location: Omaha, NE | Agreed. I think I'm going to have my machinist put the original valves back in the original heads, take some measurements, and set the truck heads up the same way. If I want new valves, I may have to have some made that match the originals since the replacement valves I got are longer than the originals. The springs above calculate to a spring rate of about 212 lb/in. Did you use these on a rebuild of a 1956 315 hemi with factory specs and dimensions. If so, I'll proceed as stated above and use the valves you have called out. | ||
Mopar1 |
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Expert Posts: 3027 Location: N.W. Fla. | 212 open or closed? | ||
Shep |
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Expert Posts: 3393 Location: Chestertown, NY ( near Lake George) | Usually that spec means 1 inch of spring compression develops 212 psi. | ||
57chizler |
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Expert Posts: 3768 Location: NorCal | A coil spring’s "spring rate" is the amount of weight required to compress the spring one inch. | ||
Shep |
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Expert Posts: 3393 Location: Chestertown, NY ( near Lake George) | Which equates to pressure exerted at on the valve. | ||
dougruffner |
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Veteran Posts: 177 Location: Omaha, NE | Right. 206(@1.2) - 100(@1.7)/(1.7-1.2) = 106#/.5 in = 212 #/in | ||
57chizler |
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Expert Posts: 3768 Location: NorCal | Shep - 2014-11-07 3:27 PM Which equates to pressure exerted at on the valve. Expressed in pounds, not pounds per square inch....the pressure will be the same regardless of the surface area. | ||
dougruffner |
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Veteran Posts: 177 Location: Omaha, NE | 212 lbs/in is the spring rate. What it means is that when compressed one inch, the force on the valve is 212 lbs. | ||
Shep |
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Expert Posts: 3393 Location: Chestertown, NY ( near Lake George) | 57chizler - 2014-11-08 3:47 PM Correct, shouldn't reply after a days work at my age. LolShep - 2014-11-07 3:27 PM Which equates to pressure exerted at on the valve. Expressed in pounds, not pounds per square inch....the pressure will be the same regardless of the surface area. | ||
dougruffner |
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Veteran Posts: 177 Location: Omaha, NE | I see you remember your Physics. Have a good one! | ||
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