7 replies to this topic

[spartacus]

My engine decided to drop all its coolant, causing it to overheat. I've taken off the (warped) head and it's had about 15 thou removed to bring it flat again

 

If I put this back on as it is, am I likely to have any issues? Car is fairly standard

[Nev]

Hmmm, I wouldn't like to hazzard a guess for sure. Did you check the block is true with a engineer's rule or somesuch? Also consider replacing the stem seals as they won't have liked the heat.

 

Your CR will be slightly up, so make sure your knock sensor is firmly attached and connected. Obviously use new head bolts and new gaskets. I'd also suggest checking your cambelt pulley tensioner is working smoothly and the water pump whilst you are in there. Do an oil change too.

 

I guess the only way to tell is to install it and see, it's quite likely to run fine really, plenty of engines get this sort of thing and it is quite low tuned/stressed by default. The cast pistons and rings are quite tolerant.

 

GL.

Edited by Nev, 19 January 2017 - 12:49 PM.

[siztenboots]

when you say dropped coolant , did a hose come off and you had a rapid loss , or just gradual water temp increase , or steam from the cap?

[spartacus]

Thanks guys, I already have a new head gasket set and timing belt kit to put on. I guess my biggest concern was whether this amount removed would cause running issues with the raised CR and reduced piston/valve clearance. Will put it all together and pray for the best! It lost its coolant via the water pump as the bearings had gone - timing was fine though

[Nev]

It lost its coolant via the water pump as the bearings had gone - timing was fine though

 

Ha ha, same thing happened to me, caused bent valves

 

I can't be arsed to work it out, but the CR will only go a smidge, perhaps 0.5:1. Nothing much to worry about, especially if you start using 97 or 99 RON.  

Edited by Nev, 19 January 2017 - 02:25 PM.

[hairy]

http://www.migweb.co...y-let-head.html

[CDNspeedster]

As I was curious about this so I did the math (making a few assumptions) and the compression change is very small (8.8 to 8.847) so really should not be a concern.

 

Not sure if there might be an issue on valve clearance when everything is hot?  Looking at pictures of the Z20let pistons they have valve clearance areas so are close.  You could check clearances with putty/clay if you wanted to be certain all is good.

 

[spartacus]

Good to know 

 

Haven't had a chance to get it really hot so time will tell, but I stuck the head back on today and it fired up easily enough.

 

I knew she still loved me