Nissan SR20-DET Block Resurfacing

[@fiatnutz]

I use a special scraper that has a carbide tip, hard plastic scrapers are also available, but not quite as effective. Thanx for the question. John...

[@Hapsmash]

I had this done to my RB. It's very healthy for your motor. My RB is a daily now. It's important to have this done on a motor you want to last for a very long time.

[@bmxguy08]

Very nice work!! i just dropped another one of my SR20 blocks at my local machine shop. These blocks always have low spots on the front left there by cyclinder #1 I have seen countless kids try and just surface the head and the they piss out oil right there. then they have to tear everything apart again! dont be cheap do things the right way!

[@rich0585]

I feel that using those purple Roloc scotchbrite disks is pretty stupid to use on a head or block. But I have had alot of success with those 3M roloc rubber bristle disks. They are made to not damage the aluminum surface, just remove gasket material. But I only used it on a Subaru, and you can pretty much glue those engines together... Great video.

[@Bowtie41]

I'm starting to agree with you,about everything on the HBS coming out the same way.Either the fixture is out of square,chips,nicks etc.,the bottom end of the block has nicks,etc,or the machine itself is outta level. John,I know you know your shit.Hell,I was a machinist for 20 years before I got hurt,12 of them in Special Products AT SUNNEN!Been watching lots of your vids the last few days to pass the time,and damn near anything put on the HBS has the same warp!Coincidence,I think not.

[@fredtflail]

thats a nice finish there.

[@fiatnutz]

As a general rule, you can see about a .1 point rise in compression for every .010" that you remove from either head ot block. Thanx for the question! JE...

[@williswatts32]

Quick question... I have a motor just like that ... After watching this you completely changed my mind to just reassembling it ... Im wanting to have it machined and possibly have the cylinders honed... What would something like that run typically? I live in the Pensacola Florida area... and im not sure where to start... Thought you may have a ballpark figure i could toss around . Thanks for the head up on the warping though! I woulda been pissed putting it back together and it leaking

[@Rekkless]

while true, in the case of a SR20 you if you are rebuilding the engine you might as well put in a thicker metal head gasket. Something like a Tomei 1.2mm works great. The factory Nissan ones are about .9mm so you actually lose compression. Which isn't so bad because you can now run more boost and timing.

[@dondebest]

This is from an S14 yes.

[@ducatiss900]

looks that way but the first cut was only a thou and it looked to me like the cut went all the way across at 1 end but not the other, this is typical of a used block, if it cleaned up in 4 thou as he says then it is normal and within Nissan's prescribed resurfacing limits. John also checked the surface finish, he is a thorough machinist, I would employ him anyday if he wanted to move to the south pacific

[@gokartmaster123]

Wow you guys are great i think i may have my sr20 done here..

[@TX97SR20DET]

@dirtrider383 On an SR20. The head alone being resurfaced is enough to where you need to adjust timing or blow the HeadGasket you just put on immediately after startup. Head and block both. No doubt lol

[@vidaddict10]

so what do you suggest to do when removing the head to clean up the surface if not getting it resurfaced at a machine shop?

[@Bowtie41]

Even on the 340 block,it didn't clean up on the first pass on the right side of the block.I dunno,I been wrong before.

[@colinbrunt]

so does the combination of resurfacing the block and head affect the compression?

[@jamesfoureight9879]

Shoul'nt the timing cover be installed for the machining? Isnt it going to sit .004 higher than the block?

[@boosted2.4_sky]

I believe that you would use a 0.004" thicker head gasket...assuming that this person would use the engine components that were being used before this treatment. The valve cover is on top of the head...

[@boosted2.4_sky]

Timing cover...gotcha...I was thinking valve cover...disregard...

[@MetallicAsian]

It won't affect compression unless you have taken off enough metal.

[@dantheman1998]

is it possible to machine the deck to smooth?

[@fiatnutz]

Same thing can happen w/cast iron blocks and heads as well.

[@DonKael]

Hey John, When you deck blocks like this, are there any precautions that should be taken as far as thicker gaskets? I'd assume this would slightly change the compression ratio.

[@fiatnutz]

@dubbelzijdigplakband - Not sure what this engine was out of. Howdy from SoCal.

[@StephenNZ]

Hi, Is the rotary scour pad only an issue for alloy blocks?

[@fredtflail]

@YoungJim409 its about .070 on an american v8 to increase it one step.

[@fiatnutz]

@benenarmor - It's the average measurement from peak-to-valley.

[@Naturepheonix]

WAIT wouldn't that shorten the block?

[@Drago2600]

Nice work, keep making these video's. Great information.

[@stanthology]

On You Tube there are some guys doing a block mutilation with an abrasive wheel. Then they do a filth injection of all the abrasive trash with an air hose! So they cram the specks into the oil return holes and oil passages, coolant passages with the air and I couldn't bear to watch it anymore. I have super-glued wet dry sandpaper to a wood backed mirror and lubed it with dish washing liquid to resurface the gasket surface of a timing cover which was eaten away but it's accessible and the gasket surfaces were good enough to be water tight. (a 318 mopar). Never a cylinder head or block deck with a sanding disk! It took a long time to shove the timing cover back and forth. But I am broke so taking a chance with the cheapskate mill worked this time!

[@bcire10]

what type of machine are you using?

[@fiatnutz]

@bcire10 Sunnen HBS1300

[@FrankaDith]

Im thinking its you that set your machine off set.

[@somekiwidude]

i want that done to my car it would go so much better

[@navysuit]

If changing the head gasket with the engine in place, how would you recommend cleaning the block? I plan to check it with a straight edge. The truck isn't worth very much, so I don't want to put much money into it.

[@SirCavemaninthewest]

Aircraft remover, and a razor blade scraper. Good luck

[@dantheman1998]

When decking a straight engine do you reference the bottom of the block so that the decking will be straight? What happens if the bottom of the block is warped too? I see that v8 engines use a fixture to help straighten the surfaces but how do you do this on a 4 cylinder?

[@dirtrider383]

this might be a stupid ? but wud that raise the compression if i did wud it be enuf to notice

[@adamruck]

Maybe it has to do with the typical design of a internal combustion motor with the exhaust (hot) and intake (cold) on opposite sides of the block. Any sort of cooling issues either by poor design or maintenance could cause warping in the same patterns as well. The bottom line is that unless you are actually there to confirm or deny the correctness of the machine, the only thing your post does is to ruin potential business for him.

[@noekiyu]

removing 0.004 inch from the sr20 block (1998cc) reduces the total displacement to 1990cc.(-8cc). Does the minuscule displacement reduction have any noticeable affect on horsepower? Or is it negligible?

[@moshegalimidi2302]

Do you raise the block to make up for the uneven surface or just take another pass? i'm asking this since i saw a machinist raise the block only from one side to make up for the uneven surface,

[@journeyquest1]

Heat. Aluminum doesnt do well with heat. When the cat starts to clog the backpressure creates heat in the head which transfers to the block. When an aluminum block overheats it can distort.....must i go on?

[@ringlol]

I wasn't getting technical, I was just stating that the height of the deck has nothing to do with displacement

[@CompressorSurge]

How much can you remove before you need a thicker HG to compensate?

[@brarautorepairs]

CompressorSurge actually if you need to remove more that the spec in the repair manual, the engine block is trash (according to the oem). Now, you could use a thicker headgasket, however, a thicker gasket will be more prone to failure and you won't know how if you'll have clearance issues with the piston and head. Finally, the belt/chain may have too much slack in extreme cases.

[@fiatnutz]

@AxSxKxONE - Haven't had any luck with them so far.

[@pokerdotjearsy]

if you don't mind me asking, what method would you recommend for removing left over head gasket material off the block without creating similar damage to this particular sr20 block?

[@eddohan]

I noticed when resurfacing, the cutter/grinder(I dont know the real name of it) rotates on different speeds. On this block it rotates pretty fast. Does that has to do with different material of the block? The finished shiny surface looks so good!

[@fiatnutz]

Resurfacing the block has absolutely nothing to do with engine displacement, only compression.

[@alfsentra]

Why my DET blow the head gasket? This is the answer...

[@fiatnutz]

@BARCDAEH - Occasionally.

[@poh86]

remember to machine the oil pump cover together with the block or oil will spill out from poor seal

[@jcadlols]

@hisveggieness very slowly. Considering he's cutting the aluminium back straight after spraying the graphite, I'd say it's a non issue. It'd be a good idea to wipe the bores and wash the galleries though. :)

[@brarautorepairs]

Very good video.

[@ElSlametySlam]

Can't tell you how much I wish people would just ask questions rather than making these terribly wrong assumptions in attempt to sound educated on the subject.

[@zapwatt]

Technically it comes from .7854(bore2)(stroke)

[@glejdihanaj6042]

nice work!

[@diegotrueno25]

video sr20

[@ElSlametySlam]

On idle I would simply not answer their question until they correct that. But as compared to all of the other interesting subjects you can find on youtube, I think I would appreciate this one, lol

[@zapwatt]

I fail to see what an aluminum block has to do with your clogged catalytic converter.

[@zapwatt]

Your idea is nice but purely academic. Aluminum has superior heat dissipation to iron and cools more easily. Alfa Romeo used the same aluminum block from 1954 to 1994 (four decades) even with catalytic converters and didn't have the problems you describe.

[@journeyquest1]

More aluminum block garbage. Best engine i had was a Nissan NAPS-Z 2.4. Cast iron block/ alum head. Engine went 350,000 mi without pulling the head, or replacing timing chain (although it was starting to rattle.) Valves went but block was still good. My Honda has 90k and cat clogged, cooking my engine. Give me cast iron block even if it is 40lbs heavier.

[@Naturepheonix]

oh whew!

[@ringlol]

Displacement comes from bore+stroke

[@pismo10]

Cool...

[@macagnoful]

Talk about stupid... He forgot to resurface the block with the oil pump on......

[@fiatnutz]

;-)