×

Sale ends todayGet 30% off any course (excluding packages)

Ends in --- --- ---

Help with blown head gasket , cylinder damaged

General Engine Building Discussion

Forum Posts

Courses

Blog

Tech Articles

Talk about engine building here. New products, tricky questions or showcase your work - If it's engine building related it's welcome here.

= Resolved threads

Author
596 Views

Hello everyone, I’m posting this because I’m very interested in know what happened . I will try to aport the most information as I can .

This is a brand new 4 piston motor (k20c1, from Honda civic type R fk8) ,build block new , I used oem head gasket , oem torque sequence and head studs APR , torqued at 3 steps of 33,66and final at 100 ( recommended by 4 piston ) the head was used ( 4 piston also ) but pulled from a running engine .

I was dialed in the tuning , basically the engine had 300 miles and I was tuning the boost due too much wheel spin and also some issues with motec , ( for some reason I had setup the rev limiter at 8000 rpm ignition cut , but on the gears with low boost for example 2 nd gear 18 psi no issues , it reach the rpm target rpm on each shifting , doing power shifting , but going on next gear with more boost the rpm were increasing, going over 8500 rpm some times ) so I was testing different setting on the rev limiter , but the only way I make it work was doing ignition cut plus fuel cut , doing just ignition cut , happened what I’ve described above . After testing the fuel cut who did the trick I stoped the car for check the logs and after start the engine over I noticed started it was running on 3 cylinder. Red flag ., then I noticed white smock … so I new the head gasket was done . I took a part the engine and I noticed blown head gasket and damaged on the cylinder top . Please see pictures attached .

Engine running e85 , direct and port injection , lambda at wot 0.82 , was following the command in whole pull , knock level low .

what I’m doing wrong ? , This is not the first head gasket I’ve replaced , I just work on these engines , and non of other customer has any issues during racing and daily driving.

talking with some collages they pointed out the block looks like wasn’t finished properly , you can see the lines and doesn’t feel smooth when I put my finger nail on the surface . Long block was brand new build from 4piston .

Attached Files

That does look like a (very) rough cut for the block decking - and even then I would expect a clear, if faint, "cross hatch" effect as the leading edge first removes metal and the trailing cut also takes a light cut. I've NEVER seen something that nasty, even for roughing. NOTE, this isn't to disparage your supplier if it was a bare block, as often they're sent in the expectation the builder will deck the block to the piston deck clearance/height they want UNLESS it was an assembled "short" block supposedly already machined to suit.

When it's like that, it can be a sign that the cutter wasn't set correctly, and the head was at a slight angle - this means ONLY the leading or trailing edge removed the metal AND, because the cut was through a slight arc, there would be more material removed along the centre of the cut than the sides - sometimes called 'cupping'. In turn, this means less clamping of the gasket between the block and head, which can cause exactly the problem you have found. If you can, double check that idea with a straight edge placed across the block between the cylinders and across the ends - I would want it to be less clearance under the middle than your thinnest feeler gauge, preferable less than a thou', but I suspect it's going to be rather more.

Compounding the potential issue, some gaskets are VERY sensitive to the finish of the mating surfaces, and even for those that aren't, I would expect ONLY a very light cut to be evident. You can see what I mean here if you look carefully at it when the light catches it - https://www.youtube.com/watch?v=JM8J6GyQ8X8.

Oh, ARP spec' 80lb.ft, but I don't think that is the problem - https://tech.arp-bolts.com/instructions/208-4701.pdf

Thank you very much for replying:

It is definitely very informative the video, to be honest these details there is something I have not get used to pay attention, what I do most is tuning and bolt on installations, now I'm trying to get more involve on the internals.

And no, our goal is find the solution at the problems, my intention or anybody else is bashing the company or motor , block parts supply . It is just about to find the root of the problem and get it right preventing to happen again.

Regarding the torque spec, I followed engine builder recommendations ( 4 Piston ), they make these engine for race proven so they have tons of experience with these engines.

Thank you very much and Ill hit them up and see if can be warrantee.

Last first, it's certainly possible they're using different studs to their specification, so might be worth double checking?

Yes, you need to double, or triple, check everything - people do make mistakes, or mis-understand what's wanted/needed, and yes, the greater the stresses and power/torque the greater the detail work you need to do during the build - these are big part of why it's so expensive to get a good builder to assemble an engine.

For a mechanically competent person the saving in doing it yourself can go a very long way to buying the required precision tools - especially if you're doing several.

While you're waiting, I'd suggest working your way through the relevant courses - I've been in the trade, off and on, for many years, and there are several points I picked up on for future reference.

Oh, just noticed what you said about the limiter not working for ignition only. Might be a good idea to have a good look at the sparkplugs, and it's common to run as much as 3 or 4 heat ranges colder/harder. This is to pull more heat out of the sparkplug tip and reduce the chance of an overheated plug tip igniting the mixture - it's very similar to a glow plug in a diesel engine, but in a petrol/gasoline/alcohol fuelled engine it can lead to severe engine damage, especially if it's also causing pre-ignition.

Agreed 100%!

Yes I'm always take my time, and triple check all, specially because I hate to drop engine etc if I don't have to, and also all the money involved.

Regarding the studs I boght it from them also specifically for that engine k20c1.

I will check also regarding spark plugs, I'm always using oem due never had any issues with tuning on Hondata for example, engine reving higher or about the same .

I wish I could attached videos and show how are the runs and also comparing the run with rev limiter issues.

I tried early but the file was too big.

Here how’s the spark plug looked soon as I removed

Attached Files

Gord has offered some great advice on the machining and mechanical side.

On the calibration side, how the engine behaves on the rev limiter and entering and exiting that system, can potentially blow the gasket. Based on your comments it sounds like this may have been a factor since experimentation was happening and the limiter wasn't holding speed down to your target successfully. If you'd like to provide logs, cals of the last few passes before failure and when it failed, perhaps we will spot something you may want to change.

The calibration was used before on the stock motor no issues. The only changes I did on the new motor was tunning the efficiency, VE tables, boost control, (reducing boost on lower gears due too much wheel spinning ) and the changed fuel cut plus ignition cut, that did the trick. Every time I shifting I do non lift shifting, so the strategy will be ignition retard -7.5 degrees , 82% cut , then rev limiter previously set at 7950 rpm ( I shifting at 7700 rpm ) and fuel cut at the same time.

I will plug the battery when I can , all taken a part right now, and I will plug the laptop to download the log, at the moment when i checked all looked good , EGT, timing, knock, lamda , boost oil pressure .

The only I can think every time i was shifting it bangs , but I'm not retarding ignition like crazy steps, not using antilag .

Ill see if I can post the last run and the previous when rev limiter was going higher at gear with more boost.

Attached Files

Alex what package is that?

From what you pictured you're hard cutting fuel all at once, since margin and range are 0. I would not expect that to cause banging unless the engine is burning lean on fuel reintroduction, which it might be. Fuel film settings play a big role here if the package you're using incorporates that system.

The way you had FFS set prior, with no fuel cut, and ignition partially cut, ignition retarded, would likely cause banging. Were you applying enrichment while on the limiter?

This looks to be the VitTuned Honda CivicX Si Package in use, with a custom flat shift functionality written by Vit for the Package. You will need to contact Vit directly to see if there are any differences in how this has been configured from the MoTeC GP Packages.

Thanks Stephen!

Mike good morning,

That package is the Viviper or Vittuned as Stephen mentioned , yes I've tried to contact him, with cero luck, I found his Instagram's and he posted on his profile pretty much '' he will ignore any DM regarding tuning questions etc ''

All I know about this package I had to figure it out by myself.

Regarding your question Mike, before without fuel cut it did not bang, just hit the limiter fast cut like a '' motorcycle engine '' and tuning on boost around 27 psi was okay, just when i turned up started to cut higher around 8500 rpm and the rev limiter was setup at 7950 rpm.

And also remember in Non lift shifting I have a ignition retard -7.6 degrees , that cause bangs . , but those bangs where different compared at when I had setup the fuel cut.

Let me see if I can upload the two runs , the one with rev limiter issue and the second with fuel cut

And I don't recall to applying enrichment.

We usually reply within 12hrs (often sooner)

Need Help?

Need help choosing a course?

Experiencing website difficulties?

Or need to contact us for any other reason?