Crankcase Pressure

[Peter Bell]

If it was all assembled by your garage and has failed so quickly surely it is up to them to at least take the head back off and investigate the problem? If it is the head gasket then they need to sort it out, if it is a piston or ring failure then that could be your responsibility.

[Guest Gargoil]

That is the problem. They are convinced it is piston/ring failure. I have my doubts but don't know enough about the subject. I may just get my hands dirty and replace the head gasket.

What have I got to loose?

[Snapperpaul]

To do a proper test crank engine with throttle open note all values as if gasket is in question 2 cylinders will be low ( most gasket failure is the fire ring between 2 bores)

Once the compression test has been done ( more than once and noted each time) a spoon of oil down each plug hole and re test

If pressure rises with oil its rings

If not it could be gasket or valve seats

[steve in stockport]

Am I right in thinking you have a pinto that's been overbored to a 2.1? Using a standard 2.0 head gasket may not be up to the job and you might need an oversize gasket from one of the usual suspects, Burtons etc.

Do you know whether the mechanics who did the previous work did all the stages of tightening the head bolts including the final stage after running the engine for 20 mins?

[Guest Gargoil]

Am I right in thinking you have a pinto that's been overbored to a 2.1? Using a standard 2.0 head gasket may not be up to the job and you might need an oversize gasket from one of the usual suspects, Burtons etc.

Do you know whether the mechanics who did the previous work did all the stages of tightening the head bolts including the final stage after running the engine for 20 mins?

 

I can't say for sure Steve. I know the mechanic was in a hurry, but what he did or didn't do I can't say. Now that you have said it, it gives me a little hope. I ordered a new gasket from Burtons. If that doesn't work, I might be in the market for a new engine....

[Guest Gargoil]

You could always put out a request for help and tea/biscuits/bacon cobs and see if a few more experienced bods will turn up and help you out popping bits of the engine out and showing you how things work. There are plenty in the South Yorks Area that have built and rebuilt pintos many times if you're unsure of taking it all to bits.

 

Thanks Dude, I might just do that. All year long I have planned to get to the Donnington kit car show, meet a few chaps etc. Would be a shame to turn up in a Vauxhall disatra.

[Grim]

i can spare a few hours sunday afternoon if you want to whip the head off and see

[richardm6994]

Am I right in thinking you have a pinto that's been overbored to a 2.1? Using a standard 2.0 head gasket may not be up to the job and you might need an oversize gasket from one of the usual suspects, Burtons etc.

 

Steve has a very good point here.

 

Standard gaskets will be designed for 90.8mm bore.....2.1 would be bored to 93mm (as they use the standard v6 pistons - are you bored yet )....given that the metal crush ring on the head gaskets are only about 3-4mm wide (from memory)then using a 2.0l gasket on a 2.1 engine would significantly reduce the gasket sealing area around the top of the bore.

 

 

Didn't you do a teaspoon of oil down the bores and found it made no difference? This would lead me away from piston rings and more towards the head, head gasket and valves.....although it's worth a re-test before you take the head off just to be sure.

 

Assuming the oil-down-bore test gives the same result as before (i.e. no difference before / after oil) and given that the leakdown test shows the pressure going into the crankcase.....I would think it not going to be the piston rings or the valves so the head gasket would be my the next suspect.

 

 

If you find no problems with the head gasket (or replace it only to find that the problem persists) then the only other thing that I can think of that would give the results your showing would be a broken piston (from running too high compression or bad ignition timing causing pinking)

Edited August 8, 2014 by steamer

[Guest mower man]

Ftting a std bore gskt to a2.1 will end in tears trust me I did it [like a pill--k]it ran about aweek ! and blew all its water out onto my feet taking the dye out of apair of bluedriving boots ! . The tales of two separate mechs and being hurried frighten me a little I.m sure there is help only needing to be contacted mower man

[Snapperpaul]

Standard gaskets are 92.5, some 92.8

You can fit them to a true 2.1 but must chamfer the pistons.

Even with the piston 0.5mm down the bore at full chat rod stretch can be 0.75 to 0.9mm

You can buy multilayer gaskets any thickness, I have a 93.5 @ 1.3mm for one engine and the cheaper Adjusa from Burtons 94.5 @ 1mm

[Snapperpaul]

Just to clarify steamers response the V6 pistons are not generally used to take a Pinto out to 2.1 as they have a lower deck height by 1.5mm making the compression very low

 

However they do fit on Cosworth rods as they are 1.5mm longer but the V6 pistons need groove's cutting for pin clips, this I have on 1 of my engines

V6 piston is 92.982 + 0.038 clearance bore will be 93.020

The normal route to 2.1 is to use the available +2.25 pistons which press fit onto the Pinto rods

93.045 for my pistons with 0.025 clearance = 93.070 bore

 

Edited August 8, 2014 by Snapperpaul

[richardm6994]

You're quite right paul....I had the v6 pistons and cossy rods in my pinto and forgot there was a 1.5mm difference in deck height that is offset by the longer cossy rods.

Edited August 8, 2014 by steamer

[Guest Gargoil]

Thanks for the advice and offers of help, if I wasn't a man it would bring a tear to my eye, but I am so a joke will have to do.

 

 

 

 

I was having a brew with the wife this morning and she saved me from choking to death on a custard cream.

 

 

She'd eaten them all.

 

I'm not sure when I will get the chance to take the head off and the gasket (really, is the Adjusa gasket is the cheap one?) doesn't arrive until Tuesday, so just to get prepared can I pick a few brains beforehand?

Should I expect the gasket a to come off in one piece or is it likely the head will need prising off?

Are there any sundries involved, The head bolts are new I think so I will probably re-use them just to prove what I find. The cam belt is also new and I intend to mark everything up with Tipex to ensure it all goes back the same.

The pistons are from the V6, (Karl Schmidt) according to the build info and modified to fit standard pinto con rods (sound like I know what I'm talking about yet, well it's all bluff), they sound expensive so might be worth moving on if I end up with a 2.0 pinto

Any other jems of advice will be most welcome, I only have basic tools such as sockets and spanners to to the job.

Edited August 8, 2014 by Gargoil

[agent_zed]

I'm pretty sure there are 2 types of head bolt one needs angle tightening and one needs torqueing. Think the newer ones are the stretch type. Worth checking to make sure which you have as it changes the way you are ment to tighten them. You also need to know if they are stretch bolts to get the max length of stretch measurement. It should say in the haynes manual.

 

hopefully i am remembering correctly.

[Guest mower man]

Don't reuse the head bolts ,they have always been stretch bolts early or late buthave differing tightening techniques early are torqued later are tightened with an angle gauge after light initial torque , I have seen them used twice but wouldnot recomend it .The adjusa gasket is not the cheapest but cheaper than some i.e. Cometic !!!!! ,cleanliness is paramount as in all engine work, clean out all bolt holes amake sure they are dry , apair of dummy studs [ old ones and cut the hex off ]aid greatly in keeping gasket aligned two pairs of hands is mutch better than struggling to put head on run a tap down all holes and blow out with air line. No oil ,grease, water or jointing paste ever!!!, take your time and do it once , its cheaper and mutch less stressfull , don't worry I ve made as many cockups as any one !! but you get great satisfaction when its right!! --------, if this is a bit of a rant mower man