Cutting "o-ring" groove in 308 liners for solid metal head gaskets | FerrariChat

Cutting "o-ring" groove in 308 liners for solid metal head gaskets

Discussion in '308/328' started by luckydynes, Mar 23, 2009.

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  1. luckydynes

    luckydynes F1 Rookie

    Jan 25, 2004
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    Okay I'm there ... time to make my own head gaskets and cut an "o-ring" groove in the top of the sleeves to accomodate them. I have some .03" stainless safety wire I was going to use and a 60 degree cutter with a .015" radius I was going to "trepan" into the sleeves ... I was looking at the geometry of the 60 degree cutter and it seems like if I angle the cutter a bit the shape of the o-ring gland will increase the load with combustion pressure (kind of a ramp on the cross section of the o-ring) ... probably just making that up in my head :) .. going for .003"-.005" wire protrusion .. boring the liners tomorrow also.

    Anyone got any advice they want to pass on?

    If this all works I'll have no choice but to play with turbos :).


    Cheers all
     
  2. mike996

    mike996 F1 Veteran

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    It's a common technique on very high compression of hi-boost turbo engines but I don't think it would be worth the bother on any sort of normal compression ratio. Are you looking to do some serious compression increases? Do you have experience doing this sort of thing or just want to fool with it to see if you can do it? If you are really wanting to increase the compression and o-ring the head seal, I'd recommend you have a shop do it that does this stuff for a living. It's a pretty common performance machine shop process. Of course, as I said, if you are comfortable doing it or just want to give it a shot, what the heck!
     
  3. davehelms

    davehelms F1 Rookie

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    As punky as the aluminum is in the head, I would rethink the idea a bit.

    If you had stated you were using a soft copper wire....maybe, but even that will dent the aluminum of the heads when torqued in place. If your budget and stock of heads is such that they can be replaced over time...then sure.

    My last effort in this direction was to machine out soft copper rings, groove the liners to accept and hold the rings in place and then remove the flame rings from a replacement head gasket leaving a little clearance. The 3/16's wide copper ring provides enough surface area that it doesnt "dent" the aluminum of the head when torqued in place and transmits enough heat that it seems to live a long life. Mounted height is quite critical liner to liner as there is no crush to these... .001" is all the variance you are allowed.

    I have used this technique on the Ferrari engines up to 14.1/1 and have had no issues. I always wanted to machine the block to accept o-rings and eliminate the gasket all together (ala F-50) but this has not proven to be required. Maserati used the identical design and technique back in the 60's on the 6 cylinder engine. Maserati's single biggest failure point is some meat head decided to use a rubber gasket cut to the shape of the outside of the engine and place BB's around the perrimiter to 'stake' the rubber gasket in place.... these leaked live a sive but the flame rings always held up fine albeit at a fairly low compression ratio with the redline of earth moving equipment.
     
  4. luckydynes

    luckydynes F1 Rookie

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    #4 luckydynes, Mar 24, 2009
    Last edited: Mar 24, 2009
    I just have a few 308 engines and am working towards building engines with boost since my 12:1 thunder motor now has 450 hrs of flogging on it. I have my own engineering co. building "other machines" so all of this experimentation with these 308 motors is just adding to my total knowledge base ... I luv tearing things down and seeing the wear/failure starting to happen.

    The Elring head gaskets are a bit expensive and can't be re-used.

    I make trick bits all the time ... cutting a groove in the top of the sleeve isn't any harder than making a crank from scratch LOL ... just looking for some dim's (edit: or advice from guys that have actual experience with this motor like how Dave piped in ... what a resource ... thank you sir)

    cheers
     
  5. luckydynes

    luckydynes F1 Rookie

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    Thank you for piping in Dave ... I got this advice from a fella' that built the IMSA Nissan GTP engines and some other experimental alcohol engines that were running 100 psi boost ... I was going to make the actual head gasket out of aluminum ... he may not be familiar with the "quality" of these castings though.

    The other thing he did which I will do when "I'm all in" is made a aluminum head gasket/shim that had machined o-ring glands in one side and also machined glands in the head ... copper seals for the actual fire ring and altered the piston compression height accordinly. I already have pistons made for the engines I'm working on but I might do this next time .... I didn't want to machine the actual heads the way he did ... Nissan was giving him heads and they were trying to win a world championship :) ... I was thinking of making the gasket/shim thick enough to put o-rings on both sides, alter compression height on pistons accordingly, and use my steel o-ring in the top of the liner for the fire ring loading ... the cooper seal thing is too pricey for my non-factory sponsored budget :).

    Dave please pipe in on what you think about using aluminum for the actual head gasket on top of the inserted wire?

    Cheers,

    Sean
     
  6. mk e

    mk e F1 World Champ

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    hurry up and get this done and working so I can just copy what you did when I get to this point with my engine :)
     
  7. luckydynes

    luckydynes F1 Rookie

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    Waiting on the super D :).

    From the last post sounds like I should use copper wire instead of the stainless wire ... but sounds like you were using the wire as the actual fire ring right against the head? Don't really want to do something where I'm consciously making the decision to throw the head away every few teardowns :( ... that makes head gaskets cheap again.

    Thanks again.

    Sean
     
  8. luckydynes

    luckydynes F1 Rookie

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    #8 luckydynes, Mar 24, 2009
    Last edited by a moderator: Sep 7, 2017
  9. davehelms

    davehelms F1 Rookie

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    I use stell shim stock on some of the English race engines that went over 14/1 but that was with a cast iron bloc that didnt move around like the aluminum albeit a wet liner engine.

    Remember, your friend had an unlimited supply of heads and blocks...they didnt care if they were reuseable and only had to last 5-600 miles...a whole different mind set there!

    The aluminum moves around far too much....O-ring the block and just use Cooper rings if you want the ultimate set up. Study the F50, that only had ONE gasket on the whole engine
     
  10. luckydynes

    luckydynes F1 Rookie

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    #10 luckydynes, Mar 26, 2009
    Last edited by a moderator: Sep 7, 2017
    Thanks very much for sharing Dave.

    One of my latest thoughts is if the head does sink a bit I can cut another groove in it slightly larger dia. than the groove in the liners making the gasket/shim "snake" thru the wires.

    Got the heads to work on for a few days while I ping pong this around for a while.

    Here's a few action pics ... Mke I was able to pull the crank out of the bottom leaving the pistons/rods/sleeves in the block ... and then heated the block and knocked the sleeves out with the pistons seized in 'em ... broke the underside of the pistons to get the rods and then bored the pistons out of the bores :).


    Cheers
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  11. mk e

    mk e F1 World Champ

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    The standar way this is done is to cut a groove in the line and fit SS wire that sits pround .002-.003. Then drop a copper head gasket on. That lets the SS wire compress inot the copper, not the head.

    I was thinking I might try a slight variation to Dave's suggestion and take TR head gaskets, cut out the flame ring (which is too small for my bore), make drop in copper flame rings and then groove the cylinders and fit SS wire.

    Or I might do a flame ring/SS wire with a rubber o-ring outside of it to seal the coolant out of the cylinder then glue the head on. I don't know.....
     
  12. Ferraripilot

    Ferraripilot F1 World Champ
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    On that note, is anyone out there using copper head gaskets? They are easy enough to have made and they last forever. I knew a late model dirt track racer and that was all he would use.

    thanks for the pics! great progress
     
  13. Ferraripilot

    Ferraripilot F1 World Champ
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    my question was just answered by another thread posting from Rifledriver:

    from Rifledriver's post:

    By the way, does it have standard headgaskets?

    I am working on a TR motor now that was butchered with O rings and soild copper gaskets. You couldnt torque it tight enough to keep it from leaking like the Exxon Valdez because the combination of the o rings and solid copper gaskets. The gaskets would not allow the rings to inbed far enough to get anything else to seal and if it got clamped down far enough the head would start to bow down its length distorting everything. Valves would lose their seal on the seats. The coolant jacket sealing was hopeless and it would even start leaking past the o rings because of the head distortion. It was all the creation of an idiot.
     
  14. mk e

    mk e F1 World Champ

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    ....I appear he's never had the "pleasure" of copper head gaskets before.

    The copper/wire seats the combustion chamber and pretty much nothing else. You have to coat the copper gasket with your favorite sealant to seal the oil and water passages. There may have be some problem with the set-up too, no way to know without more information.
     
  15. luckydynes

    luckydynes F1 Rookie

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    I'm such a tight ass ... the material for the copper head gaskets is expensive vs. aluminum sheet unless someone got a source for copper/correct formula, etc.? ... and I've got my engine stand to start it all up on and play around with ... getting the cycle throttle body intake all debugged is part of this engine too.

    I was going to machine o-ring grooves, etc. but for this test I'm thinking just coat the gasket ... can also just throw some Bars leak in there to seal up the head gasket LOL (kidding ... kinda?)

    cheers
     
  16. 246tasman

    246tasman Formula 3

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    #16 246tasman, Mar 26, 2009
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    I've used this technique on several pre-war supercharged engines and it's been a winner every time. We use a rectangular section groove with 1/16th'' stainless wire projecting 0.015'' and solid copper head gasket. The gasket is annealed (obviously) and the wire bites in without putting undue stress on the head/block

    All have been cast iron engines but I see no problem with alloy engines. I'm planning to use this on my race 250MM engine to help the 3 studs do their stuff (later 250 engines have 4 per cylinder)

    An interesting one was curing the supercharged Front Wheel Drive Alvis of blown gaskets due to a poor block design allowing the stud threads to lift in relation to the top deck face. The combustion chamber was an ovaloid shape so we spark eroded the non circular groove and this design is running in at least 2 cars now.

    The attached photo is of a blown Autovia V8 (methanol) using this. It's next race is VSCC Silverstone 25th April.
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  17. scott mcphee

    scott mcphee Rookie

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    cometics in ohio has ferrari head gaskets for less then $100 each- they are used on the top pro stock & nascar engines-
    they will also make custom head gaskets-they work why would want to do anything else??
     
  18. Rifledriver

    Rifledriver Three Time F1 World Champ

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    #18 Rifledriver, Mar 27, 2009
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    It was the way the prior engine builder did it. I would never have bothered. They had SS wire standing about .020 proud and a .030 copper gasket. Then they used about a gallon of silicone that oozed into and half clogged the cooling system. The POS never sealed the coolant, compression or oil. It ran bad, smoked like a train and overheated. There was no way the gasket was going to allow that much O ring and still have a prayer of sealing the deck. If I had known what a bunch of junk it was I never would have been involved and I really didn't want to reengineer it but that is really what it needs. To do that I would really need to start at the radiator of the car and work my way back.

    Standard Elring head gaskets work perfectly in F40 and those have a fair amount of boost. There was no reason to do otherwise but some closet clueless boy racer wanted all the neat stuff because he read about it somewhere.

    I did eliminate the SS O rings and went back to a standard gasket with a smaller copper wire O ring . If anything the copper O ring is to fill the groove Numbnuts cut in the liners. It seals great now and it will not need anything different.
     
  19. luckydynes

    luckydynes F1 Rookie

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    Yeah I was chatting with Race Engine Steve and he's almost talked me into doing just that.

    I guess the only reason I have some reservations is I have 3 motors that are "perfect" cores with proper sleeve protrusion, etc. ... been told the Cometic gaskets do not like this protrusion ... I don't want to pull all the studs just to deck those blocks for different head gaskets, but then again I'm sure the stock Elring gaskets are going to work fine on those motors ... especially if they used them on the F40 (thanks RDriver for that info). I wanted to keep everything consistent and since I have 5 motors to play with it seemed like in the long run it may make sense to make my own ... not sure now ... this is why I wait on ideas before making ANY tooling ... I hate getting committed down a long, wrong, painful path ... thought that was the case when I bought a 308 in the first place ;).

    On one of my motors had some strange sleeve wear which I now think was caused by low coolant level/localized boiling/overheat ... was only on the "top" side (inktake side .. thought it might be fuel washdown originally) of the sleeve and I've measured the distortion of the sleeves when tq'g up and they grew in this plane ... anyway this was something that I wanted to keep an eye on but might be wiser to sheeeet can the gasket R & D and invest in a good boroscope.

    hmmmmmmmmmmmmmmmmmmm ...

    I blew a head gasket on one of my fire motors but didn't use the "overnight" re-tq method mentioned by Fastradio and I never re-tq'd after heat cycling. That engine has been beat senseless now for 2 years with the stock head gaskets and a re-tq after 2 heat cycles on my engine stand ... 12:1 compression and she's detonated many times when I've been experimenting with various configurations ... which is contrary to what many have said about the quality of these head gaskets ... no surprise there though ;).

    Maybe I should just buy 10 head gaskets in one hit and try and get a discount ... the more I think about it the more it seems like I'm making myself work to save $400/engine ... maybe.

    Thanks for the input all,

    Sean
     
  20. luckydynes

    luckydynes F1 Rookie

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    How much are Boxer head gaskets? Just curious ... guy could've been being frugal ... guess that's kind of an oxymoron with a Boxer though :) ... could've been "factory gaskets or the mortgage payment" :).

    cheers
     
  21. Rifledriver

    Rifledriver Three Time F1 World Champ

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    I agree. OE headgaskets are really quite good. Several retorque's after heat cycles really needs to be done to make a head gasket work on an all alloy motor. Our Rodak in the Bonneville car had 17:1 in it for a while with Felpro racing gaskets. Never a gasket problem using that process but boy is that a PIA with SP2 heads.
     
  22. mk e

    mk e F1 World Champ

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    I was using the OEM head gaskets in my 24 psi QV with no problem.

    The issue I'm dealing with on the V12 is the large bore not working with OEM gasket or I wouldn't even be considering other options. The guys at Norwood have been getting the copper gaskets to work for years (with a .002 wire nib though, not .020-that's a LOT) so I'm leaning this way.

    I guess I could check with cometics about custom gaskets but I'm guessing the price would be pretty high.....
     
  23. luckydynes

    luckydynes F1 Rookie

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    So I pulled a few head studs 'cause one busted which I have to remove ... thought I had a "robust" setup but no ... what a f'g PITA .. still haven't got the busted one out :(.

    So I started "stoning" the top of the block and took about a .001" of aluminum off and almost cleaned up the deck. Now I have a bunch of sleeve protrusion on "unmolested" sleeves but only about .001" on the pitted sleeves that came out of this motor ... so now I don't know if I should use "good sleeves" and stick with stock gaskets or stone .001" off the pitted sleeves (making them "good" :)) and go with the Cometics.

    On another motor I busted a stud off and ended up having to helicoil the block .. .I do not want that drama again but I have to get the one stud out that broke up at the thread before I pulled the heads ... when the one broke in the block it was messy.

    Using lots of heat and pentrating oil ... I'll let her sit out overnight.

    Cheers,

    Sean
     
  24. luckydynes

    luckydynes F1 Rookie

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    #24 luckydynes, Mar 28, 2009
    Last edited by a moderator: Sep 7, 2017
    Got the busted stud out ... then got all confident and tried pulling a 4th stud which started seizing half way out wanting to tear the threads out of the block ... got it out but it was scarey.

    So I didn't want to pull any more studs out to deck the block even though that was what I was leaning towards doing.

    I started getting into cleaning the block up with a die ston and have got to a .003" protrusion with the pitted sleeves. Just .002" removal cleaned up the deck a lot ... another .001-.002" and she'll be brand new ... anyone think I've got her clean enough?

    There's still pits in this sleeve in the pic but she's a full .003" protrusion ... once I take a little off her to get her to the spec for stock gaskets I think it'll be good .... thinking about going flush and buying Cometics though ... is the deck clean enough for Cometic gaskets anyone??? ... assuming I take material off the sleeve and make it pretty much flat ... can finish stoning it off in the block after "roughing" the .001" off ... geeez I never thought I'd refer to removing .001" as "roughing" :).

    She's flat ... the dark spots are low spots which I'd estimate are .002" deep max.


    Thanks for any input,

    Sean
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