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39 minutes ago, Amin206 said:

We don’t have many options in Canada highest is 94 octane

Yeah but that's 94 AKI, which is really about 101 RON. Arguably our best unleaded here is BP ultimate 98 RON which has a 92 AKI. 9:1 will be fine.

  • Like 1

I spoke to the machine shop who resurfaced the head he’s also a builder he recommended 1.3mm head gasket over 1.5 as lower gap between squish pad and piston head will prevent detonation in higher rpm but he also said 1.5 isn’t too thick and should be fine too

i think I’ll get 86mm 1.3 gasket And cp 9:1 pistons for better response then I’ll measure piston to valve clearance if clearances were too close then I have no choice To get thicker gasket 

ECUs have come a long way, there's no need to stress running higher than factory compression just as long as you have all your compensation strategies in place to pull timing and/or add fuel for (minimum):

  • IAT
  • Fuel temperature
  • Fuel pressure
  • Baro
  • Water temp

and you'll be fine.

  • Like 1
11 hours ago, Ben C34 said:

Measure stuff before buying things

If you mean cc’ing the combustion chamber how can I figure out how much the head skimmed by cc’ing ? We can figure out how much material (in cc) removed by measuring the volume of the combustion chamber right now minus the std volume but can we figure out how much the height of the head surface decreased? so then I can figure out some number to see if the valve hit the piston head or not...

if it’s not possible to calculate that then I have no choice to put something in there to measure...right? 

 

Testing my memory and my maths skills at 4am; but I believe you would need to remove ~6.5 thou to drop the volume of the combustion chamber by 1cc. That won't be exactly correct, but quite close. So if you measured your head volume at 60cc, for example, you could work out that the head has been decked by roughly 25 thou. Which is quite a bit, and unlikely, but you just don't know.

 

That said, it is sort of more important to CC the head for the sake of correctly calculating your compression ratio. In order to work out your piston to valve clearances, you would be better served by doing a dummy assembly using your old gear (you only need to assemble 1 cylinder) and use that to measure your clearances as they were. Then with that knowledge, plus knowing the volume of your head, you can work out a good CR, what thickness headgasket you can use to achieve it, and what pistons you should be getting.

  • Like 1

Yesterday I ordered some stuff to cc the chamber so I’ll be able to get some numbers  tomorrow 

also checking clearance with my old stuff wouldn’t be risky? I’m using a new block and not sure if previous builders decked the older block or not also can’t use the new block for measuring as my older pistons are 87mm and won’t go in there

Ok bad news is all exhaust valves are leaking instead of one chamber and I measured the chamber 3 times 2 times came up as 64.5cc and 3rd time Between  64.2cc to 64.1cc I would say the 3rd one was more accurate 

but nothing less than 64cc for sure 

if the the standard chamber is 64.5 then I don’t think they skimmed the head that much? Also machine shop told me the head looks new and doesn’t look like it’s been used that much like a 25 year old head... So there’s a possibility that previous builders used a new head
but the amount of carbon buildup on valves is actually a lot and I can tell the same thing on valve seats so might be the reason for leaking 

 

  • Like 1
  • 1 month later...

Any recommendations for second ring gap ? Im at 0.019 for the top ring also during filling I noticed the black material On one of the top ring chipped 

looks like another ring set? Does cp sell them separately or I have to get a set for all six cylinders?
 

69630C90-D37E-4C50-918C-83AA4B80F545.jpeg

  • 4 months later...

Hey guys my project is about to be done just wanted to say thank you to all who helped me here I’ve learned a lot. 
I’m still taking my time measuring everything and building the engine by myself.

recently came up with this problem my k1 rod bolts are stretched i measured them after checking the clearance and I realized they are different in length by 0.003-0.004in Measured by arp stretch gauge and I decided to get new set but the problem is I can’t find rod bolts for my k1 rods
i called k1 and they said they used 3/8 with 1.6in underhead length but mine is definitely a 3/8 with 1.5in underhead length and I don’t think the previous builder changed the bolts as they have k1 tech arp2000 stamp on them

so I called arp and they recommended to get this part number 200-6207 which is also a 3/8 with 1.5in length but now that I got the package looks like the new bolts have longer thread length By 0.05in and  the head length where the socket goes is also taller 
Looks like this is the only 3/8 1.5 arp2000 that is available right now maybe mine is an older version . I called k1 twice they don’t accept they have used 1.5in length bolt but one of tech mentioned they might have used 1.5 inches in some of them 

 

1F45C023-5F28-4797-B1C6-148D8F0C3093.jpeg

C3D2E25F-5094-4BF1-A560-1EA24AF25170.jpeg

Since nobody answered my questions and some people might have these questions and end up here from Google Search I asked my machinist who also does engine building  and familiar with rb26  he confirmed that rod bolt size might be different from each other +- 0.005in so probably I can still use my previous rod bolts and also there’s no problem with using the new set that I got so just to be safe I will use the new set cause if one of the old rod bolt changed its size more than 0.001in then it’s not recommended to be used.
also after calling k1 multiple times they can’t say whether they used 1.5 length rod bolts so probably they paid someone in China to design their rods. But for replacement always use same size rod bolts and same length and same material.

Also does anyone know how to use stretch gauge while installing the rods? Cause it doesn’t look like that main girdle let you put the arp stretch gauge in there

 

 

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