12 replies to this topic

[Mynon]

I have rebuilt a 998cc engine new pistons and rings, rebore, reconditioned head to replace a cracked one new timing gears and chain etc. I cranked it without spark plugs to establish oil pressure. Then put spark plugs in and straight away had coolant leaking from between the head and the block. I read about running the engine without coolant to get the copper gasket to seal so I took the head off again and cleaned up then ran it for a while with no coolant but I could tell that it was still leaking. Allowed it to cool overnight, started it the next day and still leaking.The pandemic then got in the way whilst I waited for a composite gasket to arrive. So, what I would now like advice on is whether to run it without coolant when using the composite gasket or use coolant and hope for the best. I don't really want to contaminate the oil and filter all over again ! I have not managed to get a Payen gasket but I got a Victor Reinz brand. Does anyone have experience with this brand ? It certainly seems and looks to be good. Thanks for any advice

[johnv]

I don't think it would/should leak straight off whatever gasket you used. So I guess either the head or block face is not true, hopefully the head!

Edited by johnv, 30 May 2020 - 05:52 AM.

[cal844]

Had this recently on a 998, if it's only a slight leak... torque the head and run the engine upto temperature it should visibly reduce as it warms up. Shut the engine off when the guage hits temperature then check the leak. Mine took 2 cycles to seal and now runs perfect.

[Spider]

Most head gaskets do have a sealant on them and a heat cycle (or a few) is needed with plain water before you can add coolant.

 

I have always tended to use plain water for the running in cycle of a new engine, not just for this reason, but also, if there is a leak somewhere it's only water leaking out and not expensive coolant making a mess.

Here's the advice from ACL regarding the fitting of new head gaskets

 

[sledgehammer]

I always run the engine with no coolant for a few min's till its started to warm up the head surface 

 

shut it off , this lets the varnish soften & fill any imperfections in the head that the gasket won't fill quickly
 

fill with standard coolant

 

this is the way I was taught at college on a series , b series , pinto , in fact most / all cast iron engines

 

I do the same with all engines & gaskets - that is my personal preference

the engine never gets hot enough for any damage to occur & has a chance to settle before coolant is added

I do not suggest anyone do this - this is just the way I was taught - I have rebuilt a lot of engines over the years

 

I have found the recent copper head gaskets to be poor , and do weep if coolant is added too quickly before the warm up

 

esp on the front edge near the engine number - even with skimmed block & head , bubbles but virtually no coolant loss

 

I worry more about the fire rings , as if they are poorly made then the gasket is junk ,

 

also oil transfer hole is sometimes un raised - this usually leaks as well
 

there is a lot of junk parts out there - even if you pay good money
 

it pays to have a good look at parts & throw them back at the supplier if they are junk

all the above is my opinion only

Edited by sledgehammer, 30 May 2020 - 10:22 AM.

[GraemeC]

I do the same as sledgehammer, only I slacken and re-torque every head nut individually, once the engine is stone cold again

[Mynon]

Thank you everyone for your replies. The block has been rebored with the top surface machined. It "looks" good with a straight edge and the head has been machined too and looks equally good. I have no reason to doubt the machining so I think I will clean it all up and run the engine to warmth without coolant, let it cool, then check again ( with new composite gasket). I not so sure about these copper gaskets though reviews seem to be about half and half - so far, for me, I am putting my hopes on the composite gasket. Thanks again to all who have taken the time to reply

[PoolGuy]

I do the same as sledgehammer,

I do too, the only slight issue is that everyone will have a different opinion on what is the correct temp to run it up to. Also afaik not all head gaskets have the varnish type finish, I only use the BK450 type gasket, and I’ve never an issue on road or race engines.

[Cooperman]

The 998 can't have the BK450 gasket as that's only for big-bore engines.

I have never run and engine at initial start-up without coolant. I just fill it with water, run it through two full hear cycles, re-torque by slackening each head nut in turn in the correct sequence.

For a 998 use a Payen copper faced gasket and with newly machined block & head faces it should not be an issue.

Make sure the torque wrench is calibrated. If it is under-torquing by, maybe, 10% that can cause problems.

[1963MKI]

Ive had trouble from the moment I started my mk1 850 since i rebuilt it with the minispares gasket. So im going to change the head gasket now. I bought a BGA automotive one from ebay before Id heard of the payen one. https://www.ebay.co....872.m2749.l2649

 

 

I dont want to have to go back and do it a third time if the ebay one doesnt work, so has anyone any expierience of the BGA ones ? 

 

If the verdict is theyre not much good ill just buy a payen one, but I cant find an 850 one anywhere on the internet!?

[blacktulip]

I have just fitted a bga one and it seems to have done the trick nicely.

[Spider]

If the verdict is theyre not much good ill just buy a payen one, but I cant find an 850 one anywhere on the internet!?

 

I've not had a BGA Gasket, so I can't comment on that, but in regards to finding a head gasket for your 850, the 998 and 1100 ones are the same, so this may broaden your search field.

[cal844]

I used BGA head gaskets on two engines, when I worked in the trade I used to fit them alot.

BGA gasket will be ok.