JT's M20 Build Thread

[JehTehsus]

yeah it seems to be a design problem, i would back them off from the bottom enough and check the engagement is adequate. then just nip up the bolt with an allen key and ring spanner if they try and screw in as you tighten the nut. having said that yes it doesn't seem to cause an issue. as said above the s54 main bolts are 5mm longer so the studs may be the ideal length

Yeah shouldn't be an issue. When I got the block back from the machinist they actually had a few threads poking out, obviously they managed to tighten them properly without needing a spacer or anything. I will tackle it this weekend, along with some painting and other bits before I attach the head.

[digger]

yeah it seems to be a design problem, i would back them off from the bottom enough and check the engagement is adequate. then just nip up the bolt with an allen key and ring spanner if they try and screw in as you tighten the nut. having said that yes it doesn't seem to cause an issue. as said above the s54 main bolts are 5mm longer so the studs may be the ideal length

[Northern]

I think ARP main studs are just slightly too short to install "normally" (ie. the way you did it the first time).
This exact same thing happens on the M5x engines as well. The response is typically to install some spacer before the stud (ex. a bb) to prevent the stud from threading in more while tightening the nut, while some other people will just buy the ~0.25" longer S54 Main part number.

I've also seen people just assemble it without a thought, and yet have never heard of a failure.

[JehTehsus]

its not part of the installation except i think you back it off a smidge not bottom out or something, but that's normally what is normally ideal. i will see if i have any old pics of mine, googling suggests that maybe its normal on the m20

Googling around a bit, it seems to be related to ensuring proper torque loading on the bolt. A couple of exposed threads means the threads through the bolt are all evenly/properly loaded. Makes sense to me (that said, I'm not an ME), definitely enough that I will back out a smidgen and retorque.

edit: https://www.engineersedge.com/hardwa..._nut_13155.htm

[digger]

its not part of the installation except i think you back it off a smidge not bottom out or something, but that's normally what is normally ideal. i will see if i have any old pics of mine, googling suggests that maybe its normal on the m20

[JehTehsus]

Looks like I did indeed miss some details on the stud installation. Great catch. Now to re-torque!

[JehTehsus]

a fish scale will tell you ring drag in lb what the specs should be i think the ring manufacturer can tell you but if its like stupid high then you know you have a problem id think less than 20lb and also once you've got the all rod connected to crank the overall breakaway torque can be measured when turning the crank my guess is 10-20 ft-lb for short block

those ARP main studs should stick out a couple threads?

I would definitely guess the force I put on each piston to be less than 20lbs. I may rig something up to actually check this depending on how a breakaway test goes, but that actually sounds like the right range, thanks a ton for the suggestion.

Regarding the ARP mains, is that part of the installation? I'm worried I missed a set of directions somewhere... I turned in the studs with an Alan key till they stopped.

[digger]

a fish scale will tell you ring drag in lb what the specs should be i think the ring manufacturer can tell you but if its like stupid high then you know you have a problem id think less than 20lb and also once you've got the all rod connected to crank the overall breakaway torque can be measured when turning the crank my guess is 10-20 ft-lb for short block

those ARP main studs should stick out a couple threads?

[JehTehsus]

Quick update, now that I am back from holidays and getting things moving again! Pistons are in! Here's a big ol dump of photos for the curious.

One thing I would love to know, if anyone has any pointers, roughly how difficult to insert and move in the bores should the pistons be? I lightly oiled the skirt and the rings, and powdered the cylinders with total seal break in powder. Quite liberally oiled the wiseco ring compressor, and essentially pushed the piston into the compressor until about half the skirt was sticking out the bottom before setting into the bore and lining up etc. I then had to push 'fairly hard' to actually work it into the bore... a bit to get it to the point where (i think) the rings would just meet the top of the bore, then I 'wiggled' the compressor and piston a bit (not that it really moved at all, I basically just rotated it a tiny bit) then pushed the pistons in with my thumbs. Definitely required a bit of force.

Once in the bores I would certainly not call them slick/slippery at all. I can move them up and down a without a ton of force (one hand pushing a fair bit) but they do definitely stick. I have not this before, so I am not sure how stiff they should be.

For reference, I can no longer 'easily' rotate the crank by hand. I can still rotate if I push/pull quite hard with my hands on the bottom of a rod bearing or outside edge of a counterweight but there is quite a bit more friction from the pistons. They also make a sliding sound, and I'm not sure if this means they do not have enough lubrication (my understanding is too much oil on the cylinders can be detrimental to break in). Does this sound about right for this point in the process?

Ring gap is correct for my application, and all rings are aligned within +/-10-15 degrees of where they should be according to the diagram from total seal.
















(broke a bolt torquing the timing cover... check your torque wrench, or better yet, don't answer phone calls midway through a job!)



















Torqued in a few steps up to 50ft.lb, based on the recommendation from IE for their forged rods.


Head going on soon!

[JehTehsus]

My bad, I must have got a bad google result because I saw 285lbft not 500lbft. Is that the clutch masters kevlar clutch on IE's site? Depending on what you want to do with the car, it's worth knowing that Kevlar clutches don't like getting really hot so a metallic clutch might be better if you're into things that put a lot of heat on it.

As for high flow in tank pumps, give Deatschwerks a look, they make pretty good pumps and have better warranties than Walbro. 370lph @70psig is enough to max those injectors out.

Looking forward to seeing the build progress

Thanks for the info, I will definitely look into the deatschwerks pump. And yes, that is indeed the clutch masters kit!

[varg]

My bad, I must have got a bad google result because I saw 285lbft not 500lbft. Is that the clutch masters kevlar clutch on IE's site? Depending on what you want to do with the car, it's worth knowing that Kevlar clutches don't like getting really hot so a metallic clutch might be better if you're into things that put a lot of heat on it.

As for high flow in tank pumps, give Deatschwerks a look, they make pretty good pumps and have better warranties than Walbro. 370lph @70psig is enough to max those injectors out.

Looking forward to seeing the build progress

[JehTehsus]

yeah there is the walbro 255 or whatever thats what i meant by cheap

I don't think it was the 255, but at this point I could be misremembering. Of course, going over my notes I somehow neglected to take any regarding the pump beyond some basic flow calculations. Definitely something I will need to sort out shortly.

[digger]

Well, if there aren't any in-tank options then I guess I will have to go external. I swear I saw some that I thought would fit (some walbros at around $200ea)... but I was going off rough measurements I dug up online.

And thanks for drawing my attention to the hard lines, I would rather have something a bit bigger that will flow a bit better anyway.

yeah there is the walbro 255 or whatever thats what i meant by cheap

[JehTehsus]

Well, if there aren't any in-tank options then I guess I will have to go external. I swear I saw some that I thought would fit (some walbros at around $200ea)... but I was going off rough measurements I dug up online.

And thanks for drawing my attention to the hard lines, I would rather have something a bit bigger that will flow a bit better anyway.

[digger]

there doesn't seem to be many intank only pump options other than cheap parts with questionable quality. how good can a $50 pump be

i think stainless hardline are the ones that are most obvious as well as anodised aluminium.

i have looked too far into it seemed like a major hassle. i know some will tell you they ran stock without issue but i take that stuff with a grain of salt