Derracudas zermatt 20vt,6spd, 351awhp - July 4th drive vid

[derracuda]

aighty, thanks for the insight there on the smoking Sam. i'm gonna pressurize the cooling system here later when i get a chance and pull the plugs to see if it's leaking into a particular cylinder.

[a_CQ]

bummer indeed...good luck..

[HT Motorsport]

:( Sorry Derek bummer indeed. Im sure you'll have it back and better than ever soon enough.

[90_Koop]

Awe man. :(

[Marc]

Ugh, that sucks man. 2nd Sam's comments on the headgasket..

[derracuda]

who all with stacked gaskets have had sketchy results?

[Marc]

no problems on the v8. I did notice that I had to turn the nuts a bit on the studs after a few hundred miles and that made me glad I rechecked the torque...

[HT Motorsport]

yup just for the hell of it maybe add a bit of TQ to the studs and see if it helps. Probably too late as it may have burned a gasket but worth a shot before tearing it down.....

LC pistons next time....

H

[derracuda]

i did up the torque on the studs. i had them at 65ft/lbs, and i upped em' to 73. none of them were below 65ft/lbs when i checked them yesterday. the coolant thing just started the other day. i've got about 1k miles on the motor i think (ODO wasn't working for all of the winter).


i need to figure out my freakishly low vacuum thing before i tear it down, it idles at 12-13inches, and driving down the road it's right at 0.... not normal, and there's no intake hissing from a leak at idle, no high idle, annnnd everything's hooked up AFAIK.

[WAUG0806]

rings?

[SeStone]

When you retorque those studs, loosen them one at a time, then retorque straight to 65ft/lb. I got a good quarter turn out of mine after 10k miles.

Sam

[Repaair]

If you need to bore and hone,
bring it up to Seattle and I'll fix you up.
We can check the deck and balance if
you want.

Jim

[derracuda]

thanks Jim. i may see about a good spare block and new pistons if my leakdown #'s aren't good.

[Matt]

I know a really good machine shop here in town if you want that has all new Sunnen machines. They did my friend Brian's block and head for his GVR4. The new machines can do plateau honing...

The low vacuum numbers usually equate to a leaky hg or bad rings, obviously losing the cylinder seal some place. Are you using stacked metal HGs? If so I'd think it would be better to take the gaskets apart and put all the inner layers together but only use one sealing layer on each side.

Also, I think my ARP studs said to torque to 73ft/lbs...

[Dewey316]

When you retorque those studs, loosen them one at a time, then retorque straight to 65ft/lb. I got a good quarter turn out of mine after 10k miles.

Sam

That is some good advice. I had also torqued those studs that you got 2-3 times before i sold them to you, and they still got a little more stretch in them!

[derracuda]

i was gone all day yesterday to the historic races and didn't get a chance to get any further on her. i'll see what i can get done today, but i got church first

[derracuda]

update here as i posted in the other thread...

ok... turns out i noobed the timing belt alignment. when i put it together, i lined the cams up in the head with the circles, then put the cam gear on and made sure it was lined up with the crank pulley... i put the valve cover on later and slapped the belt cover on not thinking about the outer gear marks and the little V on the 20v's.... soo. it was 2 teeth retarded (apparently as am I), i fixed that, went for a drive, getting a good 12inches of vacuum at cruise, idle is about 16ish. throttle response isn't so laggy, but i'm only getting 7psi of boost now. i've got over everything i touched when i changed the cams out, and all my hoses are tight, the reference line to the ECU is on good, and the only thing now i guess is to check the N75...


and also checked the compression... 130-140 across the board now Cool


i unplugged the N75 and boost levels are the same. i put my 1.8bar spring in and get a nice 18psi...

anyone got a good N75 they'd let me borrow to see if it cures my problem?



furthermore, pertaining to the coolant system.. i put another cap on just to make sure i wasn't over reacting, and this other cap seems to be holding on ok so far. i'll be keeping an eye on it though.

[90_Koop]

Well you sure figured that out quick. Awesome :woowoo:

[WAUG0806]

way better than HG's or rings :woowoo: 8)

[quattro87]

way better than HG's or rings :woowoo: 8)

And especially since it wasn't out far enough to bend valves!! :woowoo:

[Matt]

you can use my N75...

[SeStone]

Check to see if you're pulling vacuum on the top WG nipple at idle...it sounds like you've got a leaky diaphram; IME 1.8bar is 1.8bar, 12psi.

Sam

[derracuda]

Check to see if you're pulling vacuum on the top WG nipple at idle...it sounds like you've got a leaky diaphram; IME 1.8bar is 1.8bar, 12psi.

Sam

1.8bar boost?... i've got a SAE boost gauge in my car and it read 18psi with the 1.8bar spring (i don't know.. it's a big freakin' yellow spring!) and the turbo response is a whole lot better, but i can tell it's not as quick as when a N75 is working.... i remember playing with my old 20vt and it not having the WGFV in, and the response is a noticeable bit slower.

a leaking wastegate will do the opposite of what i'm experiencing, from personal experience. no reference to the bottom of the WG and it'll boost pretty hard.. BTDT on my old 20vt, and i spiked 30psi on a k26 and blew the original paper HG

[SeStone]

The big yeller sounds like a 2.2bar spring, in which case 1.2bar manifold pressure is 18psi. 1.8bar should be 12psi manifold pressure above atmospheric.

I guess I proposed the leaky WG diaphram idea after you got 6psi on a stock 20v wastegate (should be a 4psi spring IIRC), and 18psi on a supposedly 1.8bar spring. I had similar things happen when I was on a bad wastegate, but there was so much other weird crap going on that might not have necessarily been the cause.

Sam

[yodasfro]

Yup it's 2.2 in a 20v in 20v it's 1.8