Moparts

.040 intake p/v too tight?

Posted By: dodgeram1998

.040 intake p/v too tight? - 09/13/13 01:59 AM

#1 Piston, all valve train mocked up, lash 0.0 , dial indicator mounted on intake rocker, roll over to TDC on the intake stroke, push down on rocker .078 movement, 5 degrees after TDC .041 clearance, 10 degrees after TDC .039 clearance,

Exhaust valve P/V clearance minimum at 10 BTDC IS .108

I don't remember if I put this 278@.050 roller cam in straight up or advanced but it looks like retarding it would not be a option with the .108 clearance.

440ci .060 over steel rod .040 HEAD gasket

looking for fixes LOL (piston valve notches). or run it BB- BOOOOMM??
anyone run .040 P/V intake clearance?

I think the exhaust will suffice
Thanks
Posted By: dodgeram1998

Re: .040 intake p/v too tight? - 09/13/13 02:27 AM

I think moparts will say .040 is to tight of a clearance , the .040 headgasket is my my quench so the easiest resolution for me prolly is gonna be a less duration cam
Other ideas appreciated
Posted By: Cab_Burge

Re: .040 intake p/v too tight? - 09/13/13 03:47 AM

If you have not set(degreed) the lobe centers yet check it and see where the intake lobes are now and go from there BTW, is this with a set of checking springs or the ones you will run? If checking springs and with a solid lifter cam set the lash and recheck it again
Posted By: LSP

Re: .040 intake p/v too tight? - 09/13/13 03:52 AM

You'll have a good bit more P to V than that (likely .020"-.030") with actual springs on it.
Posted By: dodgeram1998

Re: .040 intake p/v too tight? - 09/13/13 05:21 AM

I hope you are right about the checking spring because yes they were checking spring and I considered that the spring didn't pull up hard on the valve as I manipulated the valve with my hand as hard as I could pull up on the retainer and zeroing the dial indicator,

290 LBS SPRING on the seat I will have to get out something stronger to manipulate the valve eh. any ideas as to what tool will manipulate? on the car valve spring remover?

it will be fun trying to PV clearancing the rest of the cylinders also if I come up with good clearance on cylinder#1

I will check it out and report back

thanks
Posted By: dodgeram1998

Re: .040 intake p/v too tight? - 09/13/13 05:23 AM

I Hope you are right about them checking springs if I had .070 clearance I would be feeling it would be worth while to go on further and do the rest of the cylinders
Posted By: SuperStocker

Re: .040 intake p/v too tight? - 09/13/13 05:29 AM

I agree. Install the real springs, set the lash and recheck.
Posted By: dodgeram1998

Re: .040 intake p/v too tight? - 09/13/13 05:36 AM

Considering lash I had the lash set at zero? Doesn't the lash zero out hot ? if not then this would have been an error my part?
Posted By: Guitar Jones

Re: .040 intake p/v too tight? - 09/13/13 12:15 PM

I think with the lash set you'll be ok, you could retard the cam 2* and see what you get. I have run as little as .080 on the exhaust and .068 on the intake without a problem in my small block.
Posted By: W5DART66

Re: .040 intake p/v too tight? - 09/13/13 12:24 PM

Quote:

You'll have a good bit more P to V than that (likely .020"-.030") with actual springs on it.



^^^^^^^ this

Check with real springs.

What heads, rocker set up?

If its mopar single shaft deal it will be like .050" more plus your lash.
Posted By: gregsdart

Re: .040 intake p/v too tight? - 09/13/13 12:35 PM

You should see another .010 from adding the springs you will run and adding the lash in should get you to about .07+? I have run .050, but the pistons didn't let carbon build up where the valves brushed them, and that was a 6200 rpm stroker. So, I would look for at least .075 to err on the safe side. The really tough one is the exhaust. Don't go below the suggested minimum there, as the valve is closing when the piston is close and if there is any valve train issues you will have contact a lot earlier.
Posted By: dodgeram1998

Re: .040 intake p/v too tight? - 09/13/13 02:39 PM

the heads are indy sr 2.14/1.81 with the Harland sharps 1.6in/1.5 es . My other shot at it is to lose the 1.6 on the intake to see if that will help

I will go out in the shop later today and try again if time allows
Posted By: Crizila

Re: .040 intake p/v too tight? - 09/13/13 03:03 PM

Quote:

the heads are indy sr 2.14/1.81 with the Harland sharps 1.6in/1.5 es . My other shot at it is to lose the 1.6 on the intake to see if that will help

I will go out in the shop later today and try again if time allows

Yes, going to 1.5's will help. FYI, Hughes rents a tool that will cut the valve notches deeper with the short block assembled if you need to go that route. I did it on a sm blk and it worked good. You could also run a little looser lash than what's called for.

Attached picture 7850579-valveknotcher.jpg
Posted By: RT540

Re: .040 intake p/v too tight? - 09/13/13 03:42 PM

Starting with checking springs and a dial ind. is a good start, but then I like to use clay on all 8 pistons with the correct springs.

This summer, I had 040 on intake with a thinner gasket of 051 because I didnīt want to test with the new cometics that are 060.
This was with lash and checking springs.

Do a check with clay and correct springs.
Exhaust needs more, when the piston is chasing the closing exhaust valve, and not the other way around( intake chasing piston down).
Any flex in cam, cam drive and valve train will benefit the intake clearance.
Posted By: dodgeram1998

Re: .040 intake p/v too tight? - 09/13/13 04:56 PM

thanks for all the support
Posted By: B1MAXX

Re: .040 intake p/v too tight? - 09/13/13 05:22 PM

0 lash is the main problem. with 0 lash the ramp starts up way sooner.
Posted By: Biginchmopar

Re: .040 intake p/v too tight? - 09/13/13 09:53 PM

Like the rest, the first thing you should do is degree the cam then check P to V.

If it is close with '0' lash, under .080" with the gasket, the pistons need a deeper notch.

Do it right the first time or you will have to do it right later anyways with more expence of broken parts.

Posted By: 451Mopar

Re: .040 intake p/v too tight? - 09/14/13 09:03 AM

If it's still on the engine stand, I would just pull it apart and machine the pistons for more clearance now than be a factor in the future.
When I built my 500" stroker I went with a smaller cam because if P-V clearance issues, when I should have just milled the pistons then. Now that the engine is apart again, I'm going to do what I should have done two years ago.
Posted By: dvw

Re: .040 intake p/v too tight? - 09/14/13 10:17 PM

I wouldn't be afraid of .040" with checking spring and zero lash. You are going to gain from deflection,spring pressure and lash. If you're worried install one of your springs and lash it. That removes all guessing.
Doug
Posted By: BSB67

Re: .040 intake p/v too tight? - 09/15/13 02:48 AM

Quote:

I wouldn't be afraid of .040" with checking spring and zero lash. You are going to gain from deflection,spring pressure and lash. If you're worried install one of your springs and lash it. That removes all guessing.
Doug



Posted By: dodgeram1998

Re: .040 intake p/v too tight? - 09/15/13 07:50 AM

.025 lash in/ex and inner springs made a definitely more comfortable .075 , exhaust was a not too bad .110

I have yet to order some real pushrods and get rid of this homemade pushrod length checker which isn't rated for the full brunt of 700lbs so guys I couldn't measure P/V clearance with the outer springs and damper as of yet.

Thanks for getting me out of what looked liked a jam .
Posted By: B1MAXX

Re: .040 intake p/v too tight? - 09/15/13 02:39 PM

+ you'll gain at least another .030 with the operational equipment in there from my experience.
© 2024 Moparts Forums