FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: JimNolan on December 13, 2014, 08:30:12 PM
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Merry Christmas Guys,
I decided to pull the 410 engine I have to fix the oil leak. While I've got it out I'm going to install a 268H cam in it and put thicker head gaskets on it. Edelbrock has a steel core laminate gasket that is .038 X 4.4. So does Fel-Pro and Mr. Gasket. Does it matter which one I use. Back when I first installed it they claimed a two layer steel gasket was the way to go with Aluminum heads and cast iron block. Well, now Edelbrock is touting their composite gaskets. Which one should I use or does it really matter. Thanks guys, Jim
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When I changed to the ED heads, I used the ED gasket #7337, it had Fel-Pro name and number stamped on it. I am a fan of Fel-Pro, Mr. Gasket...not so much.
Nick
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I'm running Fel-Pro head gaskets with my ED heads. Torqued, walked away for an hour and re-torqued. After break-in run torqued one more time, having no issues. Got nothing against Mr. Gasket, just seems like some of their other stuff isn't top shelf and I never ran their gaskets at a critical assembly point like I have Fel-Pro.
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Jim why thicker head gaskets?
Potentially you can lose any benefit from quench that you'll gain from lower compression. Are they leaking, or is this a "while I am in there"
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427Stang,
By going with the 268H cam I'll increase my torque and horsepower (30lb/12hp) at 2000 rpm (where I usually cruise [gas mileage] ). The 30 hp I'll loose comes between 4000-5000 rpm(where I'm seldom at).
I'll raise my quench from .052 to .063. I'll gain 20 ci of useable motor while still maintaining a 7.6 DCR. And yes, you guessed it. I found antifreeze mixed in with the oil dripped on the floor from the back of the motor yesterday. I haven't got it torn down yet but I thought if I have to change head gaskets I wouldn't go back with the same kind and I thought I'd better ask you guys what you would recommend. You helped build this engine, what do you think. Jim
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I'd run a Felpro 1020.
Cheap-ish, easy and reliable. .041 compressed thickness, never have to think about it again.
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Jim, you might look at the new SCE head gaskets. I saw them at the PRI show and they looked real good. They are not for big motors (4.25" bore on the head gasket), but they have that raised silicone ridge around the water jacket and the oil transfer hole for better sealing. They are also side specific; you get a left and a right.
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Boy I feel little and small. There's a heavy stream of oil coming from between the transmission and the bell housing. I talked to Mike Forte and he's sending me the retainer seal and the membrane seal to fix it with. I couldn't find any oil or antifreeze coming from the heads or rear intake seal. Hopefully I'll have this oil leak fixed with just the transmission seal. I wondered why a rear main seal would go bad when I've done about six or eight of them and never had one leak before.
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Leaks like that can be tricky; at least you found it!
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Between tranny and bellhousing can be the rear cam plug or other oil passage plugs.
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Hello- I'm new to the forum, but not new to engines- anyone else use Cometic custom made Head gaskets? I am using them on my 427 SideOiler. They are pricey, but the guys at Cometic are very professional and I have had good luck with them and got exactly what I ordered and on time.
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Welcome to the site. I use Cometics on a lot of my engines, especially the higher horsepower ones. They do indeed make an excellent head gasket.
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I'll raise my quench from .052 to .063. I'll gain 20 ci of useable motor while still maintaining a 7.6 DCR. And yes, you guessed it. I found antifreeze mixed in with the oil dripped on the floor from the back of the motor yesterday. I haven't got it torn down yet but I thought if I have to change head gaskets I wouldn't go back with the same kind and I thought I'd better ask you guys what you would recommend. You helped build this engine, what do you think. Jim
Ideally you want .040" of quench. A quench of .063" will promote detonation especially at your relatively low rpm of 2000 rpm
and your use of low grade fuel.
Not sure where how you would gain 20 ci of motor from your plan.
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Ideally you want .040" of quench. A quench of .063" will promote detonation especially at your relatively low rpm of 2000 rpm
and your use of low grade fuel.
Not sure where how you would gain 20 ci of motor from your plan.
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I look at cubic inch as when the valves are closed and you're on the compression stroke. Different cams give you different useable cubic inch displacement. My 410 probably has about 313 useable cubic inches.
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Jim, you are going to blow everyone's mind... :)
Intake valve closing point adjusted displacement...it is indeed possible to calculate, but remember, depending on overlap, exhaust and other things that affect cylinder fill, a "smaller" engine based on IVC may actually fill the cylinders more than a larger one, and it will likely be different at different RPM
Fun stuff to think about though
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Ross,
I thought everyone knew that. It's not a bad thing, after all, we get more horsepower with those cams. But the actual point of usable stroke and bore isn't at the BDC of the cylinder. Can you imagine the compression if we used all of it.
BTW: I ordered those valve cover gaskets and they finally sent me an email after a month and wanted to know if I wanted a refund because they didn't know if they'd ever get them from SCE, I took the refund.
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Ideally you want .040" of quench. A quench of .063" will promote detonation especially at your relatively low rpm of 2000 rpm
and your use of low grade fuel.
Not sure where how you would gain 20 ci of motor from your plan.
I look at cubic inch as when the valves are closed and you're on the compression stroke. Different cams give you different useable cubic inch displacement. My 410 probably has about 313 useable cubic inches.
[/quote]Isn't this a different way of looking at Dynamic Compression Ratio calculations?
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Yes, it's just DCR
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I look at cubic inch as when the valves are closed and you're on the compression stroke. Different cams give you different useable cubic inch displacement. My 410 probably has about 313 useable cubic inches.
Jim, you're scaring me here ;) You are way, way off on this line of thinking. Have you ever heard of volumetric efficiency? This is the amount of air the engine uses at a given engine speed, divided by cubic inch displacement. A performance street engine can easily exceed 90% VE; 100% is not unusual. A really good race engine can see VE numbers over 125%. And yet this is with intake valves that close very late, which would result in fewer "usable cubic inches", by your methodology.
Let's say that your 410 had 100% VE; that means it would be using 410 cubic inches of air every two revolutions of the crank. In your case it might be more like 90%, so it is using 370 cubic inches of air, but it is still going to be far more than 313 cubic inches, as you suggested. Exhaust scavenging as the intake valve is opening and the ramming effect of the inertia of the air/fuel column in the intake manifold as the intake valve is closing will allow a lot more air into the cylinder at the peak torque point than just 313 cubic inches.