Engine 95 Gt40p Head Swap Valve Noise.

bbrewer5

Member
Oct 2, 2012
17
2
14
El Paso, TX
Howdy ladies and gents.

Well as the topic states, I just did a gt40p swap on my 95 stang and I've got some valve noise. It gets worse as the car starts to warm up. It almost sounds like the heads aren't getting enough oil. (My guage is malfunctioning so i'm not sure) The heads were milled, ported and rebuilt with all new parts (springs, lockouts, valve guides and seals.). I went with comp cams dual springs because I was going to put in a cam but got lazy during the install and left the stock one in for now. I reused my lifters, and my stock stamped rocker arms as the original setup wasnt making any noise at all, and I am on a budget. I did however replace the pushrods with comp cams magnum pushrods that were identical in length to the factory ones.
I'm not sure what this valve noise is, but its unnerving as I have to drive this car across country in a few weeks (1600 miles). Any ideas as to what this could be?

Thanks,
Brian
 
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When the cam is at zero lash can you spin the pushrod? is there too much play?? Are you getting oil threw the pushrods? Whats your oil pressure look like? Have you recently changed your oil filter? and if so did you put in a PH8A Fram?? (I hope not)
 
When the cam is at zero lash can you spin the pushrod? is there too much play?? Are you getting oil threw the pushrods? Whats your oil pressure look like? Have you recently changed your oil filter? and if so did you put in a PH8A Fram?? (I hope not)
I'll be honest, I didnt check every pushrod. I did check more than half and none of them spun. As far as oil getting through them, I checked to make sure all the new pushrods were clear of debris before I installed them. I did an oil/filter change about 2 weeks before I did the head swap (which i did 3 days ago). No its an stp filter, I believe an S8A to be exact. I use 10w-40 in this car due to the heat (100-105 avg), but it has been a LOT cooler the past few days. (-high 80's low 90's). I tried my hardest to keep small headgasket shavings from getting into the pushrod/lifter valley but some small ones did slip through. Maybe its clogged? Ill try an oil/filter change today or tomorrow, but theres only about 300 miles on the oil and filter.



What's the mileage on the heads? Were the guides worn any measureable amount?
The heads were totally rebuilt. Pulled them off of a 98 mountaineer with 130k. Had the heads taken to a machine shop where they were ported, and everything was replaced except the valves, which were cleaned up. The heads were magnafluxed to ensure there were no cracks. New guides, seals, springs, and lockouts were installed by the machine/race shop (the shop that did them has built a few trophy winning 7 sec drag engines so im confident they were built right). They are comp springs with dampeners inside them (the flat looking inner spring). The cam I had the heads built for has max lift of 560/598. I ended up going with a smaller cam but it havent installed it yet. I'm still running the stock cam for the time being. I'm about to drive this car across country, 1600 miles in a couple weeks and I'd like to keep the fuel economy somewhat sane. The only reason I changed the heads now was because I thought I had a slightly blown headgasket (very slow loss of coolant...never found out where it was going).
 
Mine drove fine for about 3-4k miles. It just wont have the power it could have if you have the same issue as me. The only way I hurt mine was because I had enough of the engine and its issues I mixed e85 and 93 octane and went out cutting some donuts :crazy: and broke a valve spring seat. It still runs too lol I just took it easy on it so the valve didnt drop into my cylinder. If you have oil pressure issues then add some Lucas additive (1-2 qts) in place of some oil and it will quite it down some and bump up your oil pressure. With that you should be fine for your trip.
 
Mine drove fine for about 3-4k miles. It just wont have the power it could have if you have the same issue as me. The only way I hurt mine was because I had enough of the engine and its issues I mixed e85 and 93 octane and went out cutting some donuts :crazy: and broke a valve spring seat. It still runs too lol I just took it easy on it so the valve didnt drop into my cylinder. If you have oil pressure issues then add some Lucas additive (1-2 qts) in place of some oil and it will quite it down some and bump up your oil pressure. With that you should be fine for your trip.
OK That makes me feel a little better. I think I'm going to change the filter just to be on the safe side, and I'll get some lucas oil stabilizer for it. It does have a little more power than it did before, but I was expecting more out of them honestly. It does need tuned though, so that might be why.
 
As far as solving the issue though I would get one of those pushrod measuring tools and get the proper length pushrods. It sounds like yours should but its easy and worth it. Mine I can literally rattle the pushrods up and down so i'm sure I lost a lot of power just from that. Good luck with your trip.
 
Noisy rockers are an indication that they're not adjusted properly. Even pedestal mount rockers need to be lashed correctly. These instructions from Crane Cams will show you the correct way to install pedestal mount rocker arms. The instructions are for roller rockers, but the procedure will be the same for the stamped steel stock rockers.
OK I might be slightly confused, It said to torque them to 18-20 ft/lb. Whats this whole 1/4-1 turn before reaching torque?
 
If you milled the heads, odds are the pushrods would be too long. Still, the adjustment range on the hydraulic lifter is pretty huge. I would run a compression test to ensure that the pushrod length isn't holding a valve open a little. If you want to make sure the engine is getting good oil pressure you can pull the distributor and valve covers and prime it with a priming tool to ensure oil is getting to the top of all the cylinders. You will have to rotate the engine over by hand with a ratchet while doing this.

Kurt
 
If you milled the heads, odds are the pushrods would be too long. Still, the adjustment range on the hydraulic lifter is pretty huge. I would run a compression test to ensure that the pushrod length isn't holding a valve open a little. If you want to make sure the engine is getting good oil pressure you can pull the distributor and valve covers and prime it with a priming tool to ensure oil is getting to the top of all the cylinders. You will have to rotate the engine over by hand with a ratchet while doing this.

Kurt
The heads were resurfaced, but not truly milled. I was asking the shop that built them about that and they said they just basically cleaned up the surface on them. They look milled but there isnt really any change in the deck height. Its getting oil. I wound up taking one of the valve covers off and fired it up for a few seconds. lol I'm going to get some adjustable stud mounted 1.7 roller rockers for it and hopefully that will take care of the noise.
 
Yeah, that's also another way of checking for oil pressure. Just wasn't sure if you wanted to make that much of a mess or not. The stud mounts sound like a good idea. Looks like you are on the right track.

Kurt