202 always blows head gasket

[1jzgte]

black efi 202 always blows head gaskets + pings & rattles at 3,500+ rpm (it never has been smooth throughout the rpm range like a standard 202 is)
background on the motor:
* full rebuild 20,000km's ago
* flat top pistons
* stage 1 yella terra cam

just had the head faced and put on a new head gasket blew again after about 80km's, The block shouldn't need facing cuz it was done when the engine was rebuilt

[ENV5]

you may need to use a monotouque head gasket and are you sure you are doing the head bolts up in the right order and at the right touque settings and are you doing them up in the proper 3 stages

[1jzgte]

yes,the gasket was pulled down using the method describe on the pack, done in three stages plus i was told to do the last stage abot 5nm tighter than what it says. I have tried monotorque gaskets aswel, but i was told that the graphite ones are better

[vkberlina]

Where abouts is the gasket blowing out? Between cylinders, oil gallery to water??
As for head gaskets I used to use the ACL Race series gaskets on my hot 202 and never had a drama, I used to run a Tap through the thread in the block and a die over the bolt thread to make sure they were really clean. If you are using secondhand bolts they may have stretched and may be well worth replacing.

With the vibration issue, was the engine balenced when it was rebuild?

cheers
Scott

[vkberlina]

Where abouts is the gasket blowing out? Between cylinders, oil gallery to water??
As for head gaskets I used to use the ACL Race series gaskets on my hot 202 and never had a drama, I used to run a Tap through the thread in the block and a die over the bolt thread to make sure they were really clean. If you are using secondhand bolts they may have stretched and may be well worth replacing.

With the vibration issue, was the engine balenced when it was rebuild?

cheers
Scott

[Don Sutton]

Also check that the cyl head bolts are not bottoming out before tensioning the head. Easy check is to place cyl head on block without gasket and see that bolt heads screw right up to cyl head top bolt face.

[vt1538]

What compression ratio is the engine?
What is the maximum spark advance?
What octane rating fuel are you using?
Check the fire rings on the old head gasket & look for pitting that will point to detonation.

[1jzgte]

The last time it blew, when i checked the gasket one of the firing rigs was totally blown open, As for the fuel i am uaing 98 octane. In regards to compression ratio I couldnt tell you as i didnt rebuild the engine my father had the car before me and he did.I can say though that it has flat top pitons and i am running a standard head.

Another thing i have noticed just recently is that with a blown gasket the engine
is able to rev more freely and doesnt seem to rattle.

Is it possibe that the compression could be too high? im thinking about putting starfire connecting rods on to lower compresion

Thanks for all the posts

[vkberlina]

I am starting to think this rattle your talking about might be the engine pinging and that the detonation being so bad its melting the firing ring then it blows open.
Your best be might be a O-ringed solid copper gasket, oyu could have it made a little thicker reducing the compression ratio in the process.

cheers
Scott

[1jzgte]

cheers for all the help.
Im probably gonna remove the engine and put a standard one back in to sell the car. Then ill finish building up the engine with head work/roller rockers etc.. for future use

thanks again

[Tree cutter]

Try checking your camshaft timing.Also check that the timing mark on the harmonic balancer is correct because sometimes the outer part of the balancer can slip around if the rubber that bonds the two halves together has gone soft or let go. If the balancer has spun you wont be setting your ignition timing correctly. It sounds like your ignition timing is over advanced.

[tigervh]

Flat top pistons in a 202 with a standard head generally brings compression up to around 10:1. If the head and block has been skimmed its going to be even higher. Well into major detonation territory in a 202. Starfire rods won't help as their the same length as standard ones.