Small block tuning

[novahotrod]

Hi guys and girls... Just built my nova engine it's a c14se with .5mm overbore
And x14xe style pistons fully lightened and balanced bottom end
Lightly skimmed head and block 3angle valve cut Kent ast19 cam
Solid lifters and double valve springs it all runs very close in there and
I have a problem with it blowing head gaskets.

We're can I buy a high compression gasket? Can't find one anywhere.

Thanks Warren

[garyc]

http://www.ferriday.co.uk/ they will make one for you.

Or you could try ARP head studs. Has your block been decked too perhaps that isnt flat. That said that engine is used in lots of competition engines and I dont see them having issues with gaskets even up to 190HP.

[jimbob-mcgrew]

sounds like a bit of a beast that engine, whats it kicking out ? like 120 ?

[novahotrod]

It's should be powerful if I can get it run in without it popping the Gasket on no4. Cylinder. Ill have it rolling roadrd and the carb set up lol. I know people use the engine alot but they don't normally use the high compression pistons in that set up. All I can boil it down to is too much compression.

[garyc]

I'd stick a new hg on have it set up straight away on the rollers. Your carbs could be really weak causing over heating and hg failure. What carbs u got on there? There was also a revised tightening sequence for small block heads. Did u measure the CR, if so what is it?

[jimbob-mcgrew]

any idea what the comp is ?

[novahotrod]

I didn't measure comp ratio tbf. School boy error. It had about 17 bar on our gauge according to my step dad. But I don't trust his readings. The rules we race under say we can only use the pierburg 2e3 pain in the ass carb.

[Jon_nova1]

If it's going on only one cylinder every time i would be looking at checking the flatness of the block and head while it's apart anyway. Have you also put a tap down the threads to clean them out to make sure your getting the right torque settings?

Check the sparkplugs for signs of running lean, if the head gaskets going due to that then the sparkplugs should be showing signs of melting.

Is it melting the head gasket or blowing it apart? the way it's failing should give an indication whether it's pressure related

[novahotrod]

It's making the metal ring around the cylinder go oval and blowing out the coolant seal directly above it.

[mowgli]

i assume you are doing all the basics, like new head bolts each time with lightly oiled threads, gm or elring gasket etc....

would there be any gain using a 1.6 gasket?? simply cos its bigger diameter

[novahotrod]

Yeah buying all bits straight from the stealers. Last time the head was sent away and tested as was the block there both flat. When we built the bottom end I suggested a 1600 gasket as there around 1.5mm wider bored? But the machine shop said a 1400 one would be fine? I think I'm gonna buy a 1.6 gasket and try that I think

[mowgli]

i'm not saying it will cure anything by fitting a 1.6 gasket, you could just be running way too much compression for a stock head gasket.

how good/accurate/expensive is your torque wrench & angle gauge?

[novahotrod]

It's spot on. Snap on digital one had it calibrated a month ago cause I had the same thoughts. I know it might not but at the same time it might work. And I have nothing else too loose if it blows any more gaskets I'm gonna set fire to the thing and get a Citroen!!!!!!

[meritlover]

depends on how its failing, is it between cylinders or between the water jacket and the firing ring?

could be bad fueling in no4 and/or a combination of that and bad ign timing.

[novahotrod]

Ignition timing is 32degrees advanced its blowing between the the ring and the water jacket loads of petrol going in if anything it floods up fairly easy it's no different to how we run every other engine the only difference is the high compression pistons

[meritlover]

yes but the HC pistons are common to all cylinders and the issue is just with No.4. either all the compression ratios are not balanced or there is still something physically wrong with the mating faces...or your bolt hole is choked and the stud is hydraulicing causing uneven clamping.

[jimbob-mcgrew]

" hydraulicing "

sh1ts getting serious now boy !

[mowgli]

/\ ????

having any obstruction in the stud hole will cause problems & it is basic common sense to poke a rag down each hole with a screwdriver, or even run a grinder down an old stud to create a groove & wind it in so the crap gets pushed up the groove

[Stuart]

I'd have thought if there was anything in the bolt goes then the block would crack as I managed on a 106 engine once lol

What exhaust manifold have you got fitted?
The compression ratio won't be 'that' high IMHO but the ignition advance sounds a bit too much if you ask me. What do the spark plugs look like when you take them out?

If it its a clamping issue then maybe consider having the head and block ringed.

[jimbob-mcgrew]

is it possible to check the mating surfaces with a super skinny feeler blade ?

[meritlover]

a glass plate and engineers blue is better.

[novahotrod]

Had this at the engine builders on the dyno today and guess what..... She blew a competition gasket over number 4 so we stripped head off again. (Getting good at this now) got the spare bottom end out wich has 1mm oversized normal 8v style pistons fitted the same head to the new block with a standard gm gasket and she runs like a dream. Jetted the carb set the timing and 109 bhp. Happy with that just need to change my gearing and off to the track. Old engine will be stripped and get a new head mated to it with a standard cam and see we're its at and get to the bottom of why it kept blowing.