Regal Turbo Build

Well, trans has been good, but I have another problem now. Blew a head gasket this morning. Did a quick pull and it made a weird noise, let off right away, and now it sounds like a spark plug blew out. Limped it to work and sure enough the head gasket is blown out between cyl #1 and #3. So now i get to tear it apart. It has felpro headgaskets with studs. Now do i just throw another set of those in and check the head for warpage or should i go MLS? Never ends, thankfully these things are easy to work on haha
 

v6buicks

TCG Elite Member
TCG Premium
Oct 22, 2018
6,258
15,450
Franklin, IN
Real Name
Jon
It has been running great, little to no knock even when it was 90+ degrees out. I'm kinda confused why it happened. Is there a certain power level where headgaskets typically become an issue? Im running right about 14lbs of boost.
L67 gaskets right? They should be fine at 14psi without detonation. Even my L36 gaskets with stock head bolts held on a couple "oops" 16 psi pulls
 

10sec

I haz dat teddy bear smile.
TCG Premium
Jul 26, 2008
25,942
5,810
How’d you remedy that problem?

So I put another set on, took it to the track (this time turbo'd at about 14lbs of boost) and all of the coolant ended up in the oil. VERY strangely though, because the car ran perfectly fine. We drained the oil and flushed everything out with 2 more oil changes, car ran fine, water system pressurized like it should and the coolant/oil didn't mix. I didn't trust it though because I ran a full 1/4mile with the coolant mixed with the oil as I didn't realize it happened yet. So we put in an L32 with MLS and never looked back.
 
  • Like
Reactions: TurboTPI

10sec

I haz dat teddy bear smile.
TCG Premium
Jul 26, 2008
25,942
5,810
I went and checked the oil just now, clean, no coolant. So that's a plus. It must be blown where there's no water jackets, no coolant leaking externally, not burning coolant, and no coolant in the oil. Seams to be only leaking from combustion chamber pressure. Kinda weird, but what ever. Ill be taking the head off tonite.

That's exactly how mine broke in the exact same place. I was able to drive it all the way home from where I was but about 3/4 of the way there pff pff pff pff turned into POP POP POP POP as the rest of the gasket pushed and it was straight leaking combustion.
 
  • Like
Reactions: TurboTPI

GTPpower

TCG Elite Member
Jun 5, 2012
6,294
9,609
Nebraska
Mls is usually weaker than stock.

Gm ac delco usually are the best. Victor reinz made them.

Make sure they are for supercharged engines because they have a fire ring to make them more durable.


Head gaskets always blow from detonation. Any little bit of detonation you see results in much higher cylinder pressure than you'll get from making a while bunch of power. I forget the math....it might be exponential...but I think a good rule of thumb is 3x the cylinder pressure from detonation that you would normally see without detonation.
 

Turbocharged400sbc

3800 & 4T80E > ALL
TCG Premium
Jun 16, 2007
32,538
15,846
hangover park IL
be aware this may be an indicator ofa fuel injector clogged/streaming issue on 1/3 and also that just from an airflow perspective, cyl1 would be more likely to be lean, especially without an IC

graphite over steel core gaskets arent that strong or grippy, they are more for conforming to poor mass production tollerances. the victor gaskets seem to have a more substantial perforated steel "chassis" for the graphite composite along with their more sticky coating.

all of em have fire rings.

make sure to use the newer tq sequence that should come with your bolts/gaskets

mls suck unless they started bagging them BEFORE sticking them next to a shedding piece of cardboard and packaging it
 
  • Like
Reactions: Yaj Yak
Well, it turns out it was just cyl #3. It was hard to see with it all together. Pistons look fine, so I’m gonna straight edge the head tomorrow at work and see if it’s straight.

A8959088-7272-4ECA-9A5B-49792EFABD09.jpeg


74CAFF87-90E3-43B5-8538-CA2B0AC495AF.jpeg
 
Mls is usually weaker than stock.

Gm ac delco usually are the best. Victor reinz made them.

Make sure they are for supercharged engines because they have a fire ring to make them more durable.


Head gaskets always blow from detonation. Any little bit of detonation you see results in much higher cylinder pressure than you'll get from making a while bunch of power. I forget the math....it might be exponential...but I think a good rule of thumb is 3x the cylinder pressure from detonation that you would normally see without detonation.
I was actually scanning when this happened, it picked up about .8 degrees KR during that pull. But I did notice injector duty cycle was at 95% and the afr went alittle lean. Maybe time for 80lb injectors. ??‍♂️ I’ve been scanning for over a month, injector duty cycle never went over 85% before. Maybe this cooler air we are having made the difference.
 

Turbocharged400sbc

3800 & 4T80E > ALL
TCG Premium
Jun 16, 2007
32,538
15,846
hangover park IL
you popped inside and outside.... did the tq sequence you use involve a final step of the center 4 bolts getting an additional bit of a grunt?

iirc it was the earlier sequence that they did the 3rd step of additional tightening on the 4 center ones, then they discontinued it since it takes too long.

on the arp's i go 88- 90 and the center 4 go to 94

37ftlb and 120* isnt enough unless yer stock
 
you popped inside and outside.... did the tq sequence you use involve a final step of the center 4 bolts getting an additional bit of a grunt?

iirc it was the earlier sequence that they did the 3rd step of additional tightening on the 4 center ones, then they discontinued it since it takes too long.

on the arp's i go 88- 90 and the center 4 go to 94

37ftlb and 120* isnt enough unless yer stock
Man, i cant remember the sequence or torque. I used arp specs and gm sequence i believe. But yeah, it blew out into the lifter valley also. And i dont remember any additional tightening of the middle 4 studs.
 
Well, back on the road haha. I torqued the studs like mentioned above. 90 ft/lbs and 94ft/lbs on the center 4. Let’s hope this shitbox doesn’t break again for atleast 6 months. I’m currently on like a month and a half average that something breaks. Haha. I’m lowering timing a few degrees to be safe

CEC586D9-0A73-4D8D-8710-EDC9B835317F.jpeg
 
Old Thread: Hello . There have been no replies in this thread for 90 days.
Content in this thread may no longer be relevant. Consider starting a new thread to get fresh replies.

Thread Info