Author
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Topic: Tightest piston/head quench?
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n2oMike Gearhead Posts: 2831 From: Spencer, WV Registered: Jan 2001
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posted 02-05-2002 12:48 AM
A buddy of mine had his 460 block milled to get to zero deck... only problem is, they took too much off! The pistons now stick out of the bore 0.012"-0.016". The gasket measures 0.042".This leaves 0.026"-0.030" clearance. Is it enough? The engine is a 460 with truck rods and TRW's 'liteweight' flattop pistons. It has a 248/260 solid cam spinning the tach to around 6200rpm. I've never run one any tighter than around 0.035" This tight quench doesn't seem to leave much room for error. I don't know of a thicker 460 gasket offhand, and I don't really want to go copper. Any ideas? Thanks! ------------------ Mike Burch 66 mustang real street 302 4-speed 289 heads 10.63 @ 129.3 http://www.geocities.com/carbedstangs/cmml_mburch.html http://www.fortunecity.com/silverstone/healey/367
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Rustang Gearhead Posts: 821 From: Clarion PA Registered: Nov 2000
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posted 02-05-2002 05:55 AM
I had a similar situation with my Windsor. When I put it together with .210 dome speed pro pistons and stock rods in an early (9.48 deck) block, the pistons stuck out .015". I called Fel-Pro to see if they had a thicker head gasket. The answer was no...but they had just came out (this was 1989) with a .018" copper shim gasket that I could use with the FelPro "blue" head gasket. Using the shim would put my piston/head at about .040". One thing he said to use was some permatex spray-on copper gasket sealer when assembling. I was skeptical, but tried it and never had a problem! This motor had over 12:1 compression, used stock head bolts, and made many 11 second passes and is still together today. On the other hand, I've heard of guys running .020-.030"piston/head, but these same guys also bragged about the pistons "just smackin' the head a little". You'd probably need real tight piston/cylinder wall clearance, and with a big block you'd probably need a little more room for things to "grow" than most small blocks. Another option would be milling the pistons down to get more clearance. ------------------ '68 mustang 351 clevor- 10.92@124 '67 Stang, 351W -11.18@118 '69 351C Torino-14.90@100 '78 Pickup 351W-15.56@88 '79 Pickup 460 ET=?? http://www.rustang-racing.cityslide.com/contents/contents.cfm/712231
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ccode67 Gearhead Posts: 2995 From: douglasville,ga,usa Registered: Mar 2001
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posted 02-05-2002 07:23 AM
I just went through this with my windsor, The local machine shop guru for race motors said he had run as low as .020 (dirt track oval motors that don't live very long anyway) but the pistons would sometimes leave "marks" on the head and the carbon would never cover the areas so it must have been real close, his recommendation was .040 for a street motor and as tight as you dare with a race motor but no less than .026 , hope this helps.------------------ Stuart MCA #48902 M&M #1091 67 stang 5 speed, soon to be 351W 91 f-150 xlt 98 explorer xlt sohc v-6
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ccode67 Gearhead Posts: 2995 From: douglasville,ga,usa Registered: Mar 2001
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posted 02-05-2002 07:29 AM
I left something out. Mine was .013 over the deck, .039 gasket for .026 clearance, he said run it, UNTIL we did the compression calculation, came out at 10.97 to 1 , good for a race motor but this is a street car on pump gas, cut the pistons to give .020 in the hole, 9.7 to 1 I didn't want to take the chance of not being able to use pump gas.
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Moneymaker Administrator Posts: 27499 From: Lyons, IL, USA Registered: May 99
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posted 02-05-2002 12:40 PM
We run TOny's 5.0 motors (out of the deck) at around .020 with zero problems. I have built very tight 289's with steel rods at similar clearances. Mike, Victor makes thicker "marine" head gaskets for 460's if you prefer to not have so tight a quench. ------------------ Alex Denysenko Co-Administrator and Moderator NHRA/IHRA/SRA member NHRA and IHRA SS/LA National Record Holder '00, '01, & '02 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Part time secret agent license #0089 US Class Nationals link
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n2oMike Gearhead Posts: 2831 From: Spencer, WV Registered: Jan 2001
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posted 02-05-2002 07:44 PM
Well, I called Victor. The compression on this engine is going to be pushing 12:1. The Victor rep said the marine gasket was not any thicker, and that it didn't have the steel combustion ring like their race gasket. He didn't recommend it.I DID find that Felpro makes a Pro-Stock gasket that measures 0.051" thick. It's part #1099. It has 18 head bolt holes, but can be used with standard 10 bolt heads... but the bore measures 4.66" I believe. It's over 1/4" larger than than the bore itself! I thought it sounded a bit extreme. What do you guys think of it? Thanks! ------------------ Mike Burch 66 mustang real street 302 4-speed 289 heads 10.63 @ 129.3 http://www.geocities.com/carbedstangs/cmml_mburch.html http://www.fortunecity.com/silverstone/healey/367 [This message has been edited by n2oMike (edited 02-05-2002).]
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ASTIKHOSSW Journeyman Posts: 90 From: UPLAND CA SAN BERNARDINO Registered: Sep 2000
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posted 02-05-2002 08:08 PM
CAN'T YOU JUST PUT OFSET BUSHING IN THE RODS TO LOWER THE ROD LENGTH.I THINK THEY CAN BORE THE ROD SMALL END AND OFSET THE BUSHING BY THE AMOUNT YOU NEED TO LOWER THE PISTON IN THE HOLE.
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n2oMike Gearhead Posts: 2831 From: Spencer, WV Registered: Jan 2001
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posted 02-05-2002 09:18 PM
quote: Originally posted by ASTIKHOSSW: CAN'T YOU JUST PUT OFSET BUSHING IN THE RODS TO LOWER THE ROD LENGTH.I THINK THEY CAN BORE THE ROD SMALL END AND OFSET THE BUSHING BY THE AMOUNT YOU NEED TO LOWER THE PISTON IN THE HOLE.
There are plenty of ways to fix the problem... some are just a bit more labor intensive than others. A thicker head gasket would be the easiest, especially since the shortblock is already put together. A standard 0.042" gasket will PROBABLY work. There's not much room to play with, so a slightly thicker one would be nice insurance. The Felpro #1099 pro-stock gasket mentioned above seems like an interesting alternative. Thanks in advance for any experiences and insight. [This message has been edited by n2oMike (edited 02-05-2002).]
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Butch Jennings Gearhead Posts: 633 From: No. California Registered: Apr 2000
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posted 02-05-2002 11:21 PM
Mike, I use the Fel-Pro pro stock gasket in my .030 460 (my piston's up out of the hole too). I didn't use it for the extra thickness, in fact I stuck my piston up out of the hole to compensate for the thicker gasket. I used it because it DOES have such a big diameter and I unshrouded my chamber and notched the bore to the gasket diameter....that is worth sustantial flow and power! There's one of Butcher's few speed secrets...lol. I wouldn't be afraid of larger diameter of that gasket, in fact, I'd bust the die grinder back out and use them to my advantage. Just my 2-cents. ------------------ Butch 460 powered 1967 Comet Cyclone 10.271 @ 130.069 Butcher's Home Page "Friends don't let friends drive Chevys"
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Butch Jennings Gearhead Posts: 633 From: No. California Registered: Apr 2000
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posted 02-05-2002 11:23 PM
One more thing, the only real drawback to using that gasket is that they cost around $80.00 apiece! On a budget like mine that is a big deal.------------------ Butch 460 powered 1967 Comet Cyclone 10.271 @ 130.069 Butcher's Home Page "Friends don't let friends drive Chevys"
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Just Strokin Gearhead Posts: 754 From: Tuscaloosa, Alabama Registered: Dec 2001
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posted 02-06-2002 08:36 AM
You can get them from Ford for $85 a pair.M-6049-E460
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Moneymaker Administrator Posts: 27499 From: Lyons, IL, USA Registered: May 99
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posted 02-06-2002 10:55 AM
I have some old stock (early 80's) Victorcore "M" series marine head gaskets for FoMoCo's and chebbies. They are all .050 to .055 thick and have the stainless ring around them. I used to do some boat work and still have some marine parts. They must have made a design change in them over the years Mike before they introduced their racing line. I used to swear by them in all the blower engines I did for boats or cars in the 70's and 80's. Hmmmm? I wonder if they will trade me for updated merchandise? ------------------ Alex Denysenko Co-Administrator and Moderator NHRA/IHRA/SRA member NHRA and IHRA SS/LA National Record Holder '00, '01, & '02 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Part time secret agent license #0089 US Class Nationals link
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n2oMike Gearhead Posts: 2831 From: Spencer, WV Registered: Jan 2001
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posted 02-06-2002 11:42 AM
Well, I know someone who might be interested... as long as the price is right. Let me know how much you want for them. Thanks! ------------------ Mike Burch 66 mustang real street 302 4-speed 289 heads 10.63 @ 129.3 http://www.geocities.com/carbedstangs/cmml_mburch.html http://www.fortunecity.com/silverstone/healey/367
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cpmaverick Gearhead Posts: 1666 From: Santa Clarita, CA Registered: Jan 2000
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posted 02-06-2002 12:41 PM
After block-decking due to warpage, my pistons stick .010 out of the block. Never had any problems. ------------------ -Charlie Ping 1970 Maverick Grabber [email protected] with AC and overdrive. http://www.maverickgrabber.com
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bluestreek Gearhead Posts: 1724 From: Athens,GA Registered: Jul 2001
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posted 02-07-2002 07:50 PM
Nice quench!! SCE sells solid copper gaskets that measure .050" and .062" . What's wrong with copper? BS [This message has been edited by bluestreek (edited 02-07-2002).]
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