Hey people,

 

I have recently put a 5k with a 3k-h in my 35 and has been going great untill. . .

low compression in one cylinder then i replaced the headgasket. that worked fine untill a few days later and now it has happened again but in three cylinders, i have pulled the head loff and all looks fine so am thinking its a cracked head?

:P

I have a spare 5k head to put on but will this be fine to bolt on as it was a 3k-h head that was on there?

 

Any help will be great,

 

thanks in advance guys.

Hey mate, try changing your head back to the 5k it'll be fine just low compression compared to the 3k-h.

Also did you try a wet compression test to see if your rings were worn? If not try putting about 1-2 teaspoons of oil in the cylinder chamber then do the test again if the compression rises significantly then worn rings are the case.

 

Cheers Mick.

When you say low, how low are you talking? how many test did you do? and how many revolutions did the engine do?

 

What I was always told was that you do your test 3 times and take the average of the 3 test. also to have some one turn the key for you, so that you can feel 3 pulses (compression strokes) before you stop.

NOTE: I was training as a machinist

 

with the oil test/ring test, do the compressing before and after putting the oil in.

 

If you did not write down the results of the first test, redo the test and post the results.

 

This will give me/us more info to play with

 

Chris

Hey mate, try changing your head back to the 5k it'll be fine just low compression compared to the 3k-h.

 

 

If i read that right, you say the 5K head will have lower compression than the 3K head....which is not true. The 3K head would have lower compression as the combustion chamber is half in the head...unlike the 5K which has the combustion chamber in the top of the pistons (dished pistons). All depending on the type of 5K it is.

 

I'd also recommend to do the compression test a few times and take the average....what kinda pressures are you getting atm?

has this engine been built with flat tops specifically to suit the 3k-h head? if not then put the 5K head back on.

 

cheers

 

brian