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Formerly weebeastie
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Yes, GT28RS. When does full boost come in on yours? Ours both start pretty low because thats their nature. Mine can hit full boost before 3500 RPM's. Which exact turbo do you have? I have found that D's with aggressive timing and turbo's that are a bit laggy and come in like a jackhammer are more apt to blow head gaskets because the pressure comes on all at once.
 

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Discussion Starter #422
My turbo is a GT3271. Because of boost by gear, peak boost varies. Based on the way I've got it setup, i can reach max boost in 3rd.

On my most recent test drive, I moved duty from 54% to 56% and got another pound of boost out of it. Also pulled another degree of timing out of the VTEC map in all boost columns. In 3rd, I hit 17psi by 5500 rpm at 80% throttle.

Reading my data logs I guess I've been reluctant to press the pedal to WOT in 3rd lol, probably because I hate speeding too seriously on the streets.

At the top of 3rd, I'm doing just shy of 130, and it doesn't take long to get there lol. That speed is just retarded on the street, even on the highway! If I get pulled, ive got zero excuse and I'm probably going to jail. So I'm conscious of when I find an area of road I feel is a good candidate for a rip.

It had also just rained during my test drive, that was the first time I got the federals to light up, so I had to feather it to maintain steerability.
 

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Discussion Starter #423
I like the idea of the different/new head gasket.
I've got a buddy coming over this evening. We are gonna try a few more pulls with about 2 total degrees pulled out of the map in VTEC. If it keeps pushing coolant, he's gonna stay over tonight and we are gonna rip the head off and inspect. If head is still straight and within warpage limits (highly doubt this) we will just clean things and put a new HG.

We will see what happens!
 

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Discussion Starter #424
Yup, still pushing coolant lol, even with the 2 degrees pulled. Pulling the head now.

I did notice it lost a little bit of power compared to last hard pull, Actual timing now is 9 degrees at 15PSI (was at 12-13), so its quite a bit less timing. I will probably shoot to maintain 10-12 at 15psi, and pull another degree per PSI with higher boost.

It was raining outside, and in second gear was the first time I got it to spin continuously and bounce rev limiter haha. The backfiring sounded like a 9mm lmao.
 

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Formerly weebeastie
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12 degrees at 15 psi, and around 10 degrees at 18psi.


I'm running between the two on a full on pass, sometimes reaching 18.
 

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Discussion Starter #426
12 degrees at 15 psi, and around 10 degrees at 18psi.


I'm running between the two on a full on pass, sometimes reaching 18.
Could you do me a huge favor and review some data logs, or even go for a slight pull to see what Actual vs Table timing looks like for you?

I'm curious what your data logs say about your Actual timing during a pull in those boost ranges? Does Actual match your Table timing, or does Actual show another 10-12 degrees added to it like mine seems to?

If Actual matches your table timing, then we are close to being in the same timing ranges. Otherwise, if your Actual really does show another 10-12 degrees added to it like mine does, then JDs tune was actually even more conservative in those boost ranges on pump gas than your tune shows. The only time the timing went higher was with E, where the ethanol content added roughly an extra 7-9 degrees across the map (which is a lot, i will keep that removed honestly).

I'm wayyy further pulled back now on my Actual timing now than your Table timing. My Actual/Total timing at 15psi since pulling 2 more degrees from the table is about 9 degrees final. My table timing in that same range is -3.5 degrees at 15psi.

She's definitely not as responsive as she was with about 2-3 more degrees in it.
 

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I run a 93/110 mix (just FWIW), but wonder some things about your cylinder pressure. Which cam is in it now and where is the cam timing at? If you've got it that dialed back, it shouldn't be pushing coolant unless there was a pre-existing problem or something isn't quite right. Is this a Y8 or Z6 bottom end? Sorry, my mind went a lot of places. I think mine is actual timing in the table, at least as far as I know. In the logs it reads the same timing. Mine had more timing in it, and popped a gasket, so I dialed it back a bit to this.
 

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Discussion Starter #428 (Edited)
So I got the head pulled. Was blown block side, intake side on cylinders 2 and 3.

20200509_193310.jpg

20200509_203623.jpg


Head side looked great, nice and defined fire ring circles around each cylinder, no real evidence of blow by with one exception:

20200509_203436.jpg

Its hard to tell, but it also looks like it might have been passing between every cylinder on the head side. There are these tiny little curious black line marks between cylinders that I've never seen before on any car with a blown HG. Its almost like there was a pinhole leak in the fire ring between cylinders, causing gasses to pass back and forth? I don't know. I've never heard of a selective leak point on a head gasket lol, especially not with such even symmetry... in a row in a line? Really? Haha. I'm thinking it has to do with some kind of imperfection in the Viton coating, cause the fire rings on the gasket side were perfectly intact on the head side and showed no evidence of blow by.

In either case, I put my straight edge across the head in MANY places checking for flatness. I could not get a 0.0015" feeler blade under the straight edge anywhere, couldn't see light either. The block is also extremely flat, so im not concerned with it being warped.

I'm still going to take the head to the machine shop to get a second opinion on flatness. Their straight edge tooling is light-years more reliable than my cheap China $50 24" straightedge. If they say its flat, then I'll put it back together next weekend.

Also going to drop off the B16 stuff. Got the GSR transmission torn down so I could take the cases to get hot tanked with the other parts. Also going to have them build the head while its there, not going to bother with doing it here. It costs $50 more for them to pull valves, lap, and rebuild. Need to get valve stem seals at some point...









 

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Discussion Starter #429 (Edited)
I run a 93/110 mix (just FWIW), but wonder some things about your cylinder pressure. Which cam is in it now and where is the cam timing at? If you've got it that dialed back, it shouldn't be pushing coolant unless there was a pre-existing problem or something isn't quite right. Is this a Y8 or Z6 bottom end? Sorry, my mind went a lot of places. I think mine is actual timing in the table, at least as far as I know. In the logs it reads the same timing. Mine had more timing in it, and popped a gasket, so I dialed it back a bit to this.
Its the Colt Tri Flow V2. When I dialed it in, I set cam back to basically factory mechanical timing, using a degree wheel and intake lobe centerline method on #1 non-VTEC lobe that began to actuate dial indicator first (due to staggered lobes). Basically, it is factory cam setting, with Colt increasing the intake lobe stagger a bit and reducing overlap for the turbo application.

Y8 block.

With the almost 25 degrees in it on the E tune at 20PSI, it no doubt wrecked the HG with that much timing in it. Once that viton coating gets blown out, its almost impossible to seal back up, since the spring action of the gasket is also compromised, as the area blown out vs non blown out has a .001" gap between the viton and the fire ring spring metal. It doesn't take much after that to blow past the fire ring spring.

I don't think anything is mechanically wrong, I mean I beat the crap out of this thing on 15 psi before the dyno session to make sure no issues were lurking, with about 20 degrees table timing in it, no pushing coolant to speak of.

The only time it decided to push coolant was after I got back and did a pull on 21PSI with the sensor corrections adding almost 10 more degrees to table timing.

I think it will be happy on E, with timing around 10-12 degrees total, between 15 and 17 PSI and a new HG. Cross fingers!
 

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I agree with that last statement. If its just gonna be a street car that you want to have fun in, then 15-18 psi is going to be extremely fun on the street and will be safe at 10 around that 17/18 psi mark.
 

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Discussion Starter #431
When I watched this, you have no idea how sad I became....


Until I realized it was an Accord F22 lmao! I was in disbelief that this guy got 1060whp out of his Z6, until they started talking about Accord heads haha. I swear it looked like a Z6 head not zoomed in!
 

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Discussion Starter #433
improper surface finish on the head?
defiantly lifted so prolly not
Check this shit out, was just looking at the HG again. You guys ever seen this before?



Looks like a normal blown HG right? Look what happened when I spread the layers:










Both blown areas show fire ring embossment fractures? I've never seen this before. Anyone else? The embossment fatigued at the center point of the crush, then what, cracked because of cylinder pressures getting up and under the embossment and vibrating it to the point of cracking? Like putting a blade of grass between your thumbs and blowing past it? Or just the action of flexing a ton of times during head lift?

Or maybe the increased head bolt clamping force squeezed the fire ring embossment to the point of stress where it could fail easier?

At a loss on this one, any number of scenarios could have played out that caused this. Bottom line, the only thing I can think of that would make the fire ring embossment so vulnerable to that kind of damage is consistent and repeated head lift cycles.


I checked my other blown HGs, none showed this symptom:












Anyone seen this before? The gasket with the fractured fire ring is the Cometic. If there's ever been a reason to pull timing, its pretty obvious now lmao.
 

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Discussion Starter #436
Looks like I'm limited for sure with this setup then. It'll be at 15-17psi, 10-12 degree max at roughly 300whp. I'm cool with that :) should keep me satisfied for a while till I build the B.

Even with the B, I'm not planning on going to the moon. I just want HG reliability lmao.
 

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Discussion Starter #437
but the head did lift so what do you want..:)
Yeah, I did some searching... seems like consistent head lift can cause the embossments to fracture, regardless of HG manufacturer.

I'm actually impressed with this gasket then, it managed to maintain seal during lift, but began leaking only once it reached material yield and cracked. That's what a good head gasket is designed to do.

Still going to use the JE proseal, since I already bought it. Bringing the head to machine shop Monday to get their opinion of flatness. If they give the thumbs up, should be running next weekend.
 

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Looks like the fire ring is toast! Hmm...........

Maybe it will like this new gasket better than that one. But you went oversized on the studs right? 11mm for the SRT-4. It should've had enough clamping pressure with those. Did you follow the ARP instructions and not the inter web instructions on torquing them down?

This has me a little baffled. I'm betting that during tuning on one of the lean tries it fried the fire rings a little bit not he Cometic which then cause the weakness to form.

The more I see from yours with such good/detailed pics, the more I don't think I'll ever run a Cometic on a D or a ZC. Not that many options though. Golden Eagle makes one I suppose.
 

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Discussion Starter #439
ARP instructions all the way. The only thing i did was go an extra 5 ft/lbs, from ARP recommended 85 to 90. I went to 85 for all of them in 3 steps, then added an extra 5 on the torque wrench handle. Went to tighten, none of them honestly turned any further lol, they all clicked. The friction against the nut was achieved and wouldn't turn any more, so trying for that extra 5 did nothing. The preload should have been what ARP prescribed in their instructions at 85 ft/lbs.

Its weird that ARPs instructions for 11mm B16 bolts are 80, but SRT4 is 85. SRT4's are a little shorter though, maybe that has something to do with it?

Torqued head according to Hondas pattern. I have it memorized.

It seems a lot of the places on the internet where I've been able to find people complaining of this issue with the fire ring fracturing were using Cometic's, though I'm not trying to knock any parts maker.

We'll see how the JE does!
 

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Praying for better results with the JE

You'd likely freak if you knew what gasket I'm forced to run on the ZC because of lack of availability.
 
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