Back on topic now. I was having head gasket issues and blowing compression into the cooling system. I smoothed the heads and cylinders out with a flat grinding table/stone and sand paper. Have not had any problems since. I believe Mickey is correct with this issue and he helped me solve my problems with his 840 kit.

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2012 VIBRANT blue Teryx 4, Muzzy pro's, ECU reflash, custom cage & roof, windshield, 14" STI HD Beadlocks 29.5x11x14 Outlaw 2's, Warn XT40 winches front & rear, bedlift 2" Highlifter kit

2010 black, FST 840 stage II cams, DASA intake & injectors, BF throttle bodies, Msd, Muzzy Pro`s, Snorkeled, Warn XT40, 14" STI HD Beadlocks 29.5x11x14 Outlaw 2's EMP bumper, Custom rear Radiator, Unisteer

If you have been reading my post for any time you would know I'm not one to quote HP numbers.General rule of thumb is a good performing motor is going to be 1rwhp per every 10cc of motor size,give or take. If you see numbers way bigger then that you know somethings up.

2 things that I always do. Just like the comment above, use a flat granite stone with a 320 grit wet/dry paper glued to it, use water when grinding flat, use solid smooth motions, look at it every 4 or 5 movements, do both the heads and the cylinders. The second thing I use is “Permatex® High Tack™ Spray-A-Gasket™ Sealant” (its dark red in color when you apply it), put a light coat on both sides of gasket. Don't use any other type of sealant, Permatex did there homework on this one. This helps in those last imperfections that you cannot grind out. This combination has worked for me and I have never blown a head gasket. I absolutely abuse these motors in our desert racing with no problems.

Check this out:

That is exactly what my heads looked like before they were hand ground on a slab of marble and sandpaper. No more leaks.

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Wow, looks like alot of people have had head gasket issues. I have blown two sets and finally "crossing fingers" have seem to have the issue fixed. I have had my jugs swapped as cores and used my factory heads. The second time I had them sent off and they were suposed to be flat or true from Millenium and they blew. Had them tell me it was a install issue.. Yeah right.. Funny thing is sent them to Mickey and he lapped them and I installed them the same exact way and my head gasket issue seems to be fixed. I tend to believe that the issue is the flatness or trueness of the surfaces. But, I also believe that this issue should be made clear to the customer or end user. To many people have battled this issue throwing labor and money down the drain. Personally I battled this issue 2 times. The first on me with the milling marks, second on Millenium for shotty work that they refused to make right.

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2008 FST840 STAGEIII , MUZZY, CDI, VJOHN CLUTCH KIT,PWR RADIATOR, CUSTOM CAGE, AND BLA BLA BLA...

As a builder, I have had my share of 840 head gasket issues. The surface finish of the heads and cylinders IS extremely important but it is not a cure all. I have had issues with ductile iron sleeved cylinders and with Nikasil cylinders. On all of our 840 builds now, we use 3 layer Cometic head gaskets with ARP head studs and copper wire o-rings. This has solved most of the issues but even with these preventative measures, some continue to have issues. I think we are dealing with cylinder heads that aren't rigid enough in the deck area and are causing the issues. My 2 cents.

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Chris@BenchmarkPerformance.us
Benchmark Performance
760-484-0986
Engine Specialists, Side x Side Parts & Accessories, Discount OEM Parts

AMEN, Im having this issue now, my deal is that i got my 840 engine kit and heads from the builder, the heads were very pricey too. i emailed him with the problem and asked him if head studs would cure this problem, his reply was that he has told everyone that the head and jugg must be 100% true,and he has 1000s out there with no problem at all, i then emailed him back and reminded him that i purchased the 840 kit and his heads and i would think that they should have been 100% true and even reminded him how much i paid him for his heads and i had about 8 hrs on 840 with blown head gaskets. its been almost a month now and i havnt got a reply on my email :rm_thum bdown::r m_thumbdown:

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09 muzzy pro, dalton, MSD,fst 840 stage 3, +1 1/2 valves and porting,dasa 38mm throttle bodies, larger injectors.

I'm getting ready to do a 840 kit, I sure would like to know who has this figured out before I end up a pissed off customer! One more question for the builders - if we know there is a problem why don't we knock the compression ratio down a point? has anyone tried this?

I don't think compression to a certain point isn't the issue. We have ran our teryx at the 11-11.5 range for years. Its knowing what will work for you. I have never blown a single head gasket in any teryx motor i've built but I follow certain rules. I make sure things are finished and trued properly, I use stock head bolts with ARP tork lube, I add 5 lbs to the stock tork #, I use permatex high tack adhesive on the gasket, I use a temperature guage, and most importantly I use Evans coolant. Weak cylinder heads will benefit from evans coolant because of the liquid staying in contact with the surface of the metal, traditional coolants create a microscopic vapor layer around the chamber that can cause uneven heating of the head. I learned this years ago doing boosted ecotec motors in our sandrails, they were notorious for the same problems, I switched years ago to evans and with following most of the above procedures my warping problems went away. 2 years ago we ran into a heating issue doing the 500 mile Vegas to Reno offroad race, we ran 90% of the time at 230-240deg, we couldn't get around it, we had to run, we finished 2nd overall and still run the same cylinders on one of our motors. Read the technical descriptions on their website. Also a temperature guage is really important, most problems can be traced back to overheating of the components, an idiot light on the dash just won't do it!

I know all about coolant additives and there benefits from preping and racing a Class 1 car. Bottom line is I have enough on my plate keeping a race car together and I don't need another toy to work on.
Are there head gasket issues with std bore kits?