.03" on a turbo'd engine? Ouch... hate to see piston slap under boost. You might want to consider closer to .045" quench when you boost it. You can take it up to .05" and still see benefits from it, but beyond that it won't help out much. You could probably get away with .03" clearance with hypereutectics and a tight piston clearance (and no boost) so the piston doesn't tip when cold. You could probably rig up some oil sqirters to keep the piston crowns cool. I saw a thread on 60degreev6.com awhile ago where someone rigged up some squirters, but I think that was a rwd block. And I think there were some issues with the 3 & 4 pistons not getting oiled... still worth a look though.

 

Well according to my measurements, the 3.4 had a .0305" quench from the factory.

The pistons protrude from the block .0095" measured yesterday with a depth mic. The head gaskets are .040" compressed height. .040"-.0095"=.0305"

I'm planning on spinning this thing up to 7k, don't need any flaws.

 

Read my post in your other thread, the 3400 head gasket is .060" compressed thickness.

 

Correct.

The 3.4 gasket is .040" and the piston is proud of the block .0095" this means the 3.4 has a .0305" quench.

I have 3500 gaskest now, but thought of using the .045" oversized 3.4 gaskest to make the quench .040".

3400 gaskets have a 3.75" bore, 3500 gaskest have 3.8" bore, I know both are .060". This is why 3400 gaskets are 11.56:1SCR and 3500 gaskets are 11.5:1.


BTW: ordered the cam today. I used Dave's cam specs in his 3500, but lessened the duration to avoid the piston/valve slap (he has 305.2 advertised duration on the exhaust ), and decreased the lift a little because my spring bind at .5613" lift (he gets over .6").

I'll post the card when I get it, but his is 232/238dur, .539/.549 lift with 110* seperation and the intake side is 4* advanced. Mine is going to be .510/.520, but won't have the final dur numbers until it gets here after bench testing.

 

.03" quench is fine on a stock 9/1 cr engine that rarely sees past 5k, but your combo's a little past that.

 

I got my cam this week and it was wrong :no:
I was supposed to get .510"/.520" with a 230/236 duration 110* LSA 4* advance and I got this...

Even with with 1.6 rockers, it's .485"/.496" lift and the duration and advance is still less. This cam is showing 306hp@6500 265tq@5500 in the SIM vs. the 309hp@7000 266tq@5500.

I installed it today anyways, and the lifters are soaking in oil. Also purchased the pushrods. Now the last major item to buy is the header materials.

Thinking about building the old 3.1 with twin turbos and 3400 heads, so it will drop right in place of the 3.4/3500 while it's out getting 3400 pistons (9.1:1SCR for boost). Then the 3.1/3400 turbo kit will bolt right to the 3.4/3500 when it's ready This will also give me a change to fabricate/test a DIS conversion for the 3.1/2.8's so they can use aluminum heads as well.

 

Started fabricating the alt mount brackets. Just so you know, the stock RWD 60* brackets will work with some minor modification, but I need room for some turbos...




Not really happy with the placement of the alt. Lower would be better, but the huge engine mounts are gettin gin the way. I made this prototype out of some scrap AL (probably see the extra tooling marks in it, lol). Might move it to get some more room for the headers.
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Sorry for the dalay in updates, been working on a few items like a PCV catch can and FWD dog-bone mounts (billet CNC'd )...

 

Enlarge the holes a little on the P/S bracket...



A/C bracket needs one new hole...


The neighbor at the shop re-builds alts and starters, and I asked him today if he has any GM alts layning around. He said yes, but if yours works, I'll rebuild it for free, and it will look "pretty". Let's see what kind of job he does, neighboly love for ya, lol.



sorry about the slow-motion, but things get tight with 4 kids, two jobs, four cars etc etc...

 

Before cleaning/glass beading....

Close up of the holes enlarged on the iron head coolant neck. This means so far all the stock brackets can be used, but I will have to machine an adapter...


Cose up of the mounting holes moved...
Some new problems arised, though. Now the TB isn't going to work, it's on up-side down in the pics because the black alt bracket and alt is in the way. I may have to swing the alt down a little and fabricate a replacement (for the small black bracket), re-configure the TB, or use another TB. The alt bracket has two bolts and only two contacts on the head, this could be unstable at high RPM's, so need to figure out something to make to hold the bottom bolt hole to the lower boss on the front of the pass side head.

The A/C bracket, I feel comfortable with. It has two bolts to hold it, with opposing contacts on the head for stability, but the new bolt hole is through some thin cast aluminum and I don't want it to break. To remedy this, I plan on using a steel sleeve over the bolt behind the bracket - so it gets "sandwiched" between the bracket and head when torqued down.


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I want to put the turbos on right now, but i promised some people there would be N/A numbers for the FWD head swap.

 

Wow, this is coming along pretty good. Been going for a while, but it looks good!

 

OK 6 months later and it's still not done. Working 2 jobs making up for the wife being laid off has made time scarce.

Besides that this thing has gotten out of hand now.

I'm staying at 11.5:1 compression and boosting it. If I need to mix up some home-brew C16 so be it.

I ditched the MegaSquirt and bought a Wellems dual power chip burner, got the TunerPro RT software and GM 3 BAR MAP and would like to run the modified SY/TY code ($59).

Here's some new pics...

Custom Cometic MLS gaskets...





Power steering is gone. Went with a S10 box



Brought the motor home and they finally meet



Turbo test fitment



Fabrication time

 

Alternator gets moved south



Downpipes will go between the primaries





More fabrication






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Still haven't had a chance to make the flanges on my CNC machine, but soon. Here's where the turbos will sit...








I'm hoping maybe later to fit in the Siginaw P/S pump (res-less), but to me A/C is more important here in FL.

Since I last poted here, I also managed to get a 9bolt from a T/A with disk brakes, 7.625" 3.45 gears. That was also the doner for a 3" exhaust with dual 3.5" exits from Dynomax, and the S10 steering box.

 

I'm alittle worried about the bottom end of that motor....... If you wanted to stay V6, the 3800 (L67 or L32) has a VERY strong bottom end, w/ stock pistons is capable of 500 whp, and with forged pistons is capable of 900hp.

Where is S.Fla are you?

Ray

 

Bottom end may/may not hold. It's currently a nodular iron crank forged rods and cast pistons. I have a forged crank as a backup, but it needs some mahining to fit and the DIS ring has to be swapped, but I doubt I will stay with the early 60* block before swapping to a caomplete 3500 motor, but until then I have one more Gen1 block to hurt before that happens.

Our shop is in Deerfield Beach.

 

check this Grand prix out with a 3800 and twin turbo running 8's....

www.redgtx.com/ZZP.wmv


Ray

 

If you read the beginning of the thread, I talked abou tthe twin turbo 3800 Firebird in the 8's.

Here's head flow comparisons between some 60 and 90 degree heads. The 3500 heads are stock mind you, and look at the $1600 Abbot flow numbers

 

Had about 1.5 hrs to fool around with it Sunday between the son's soccer practice and dinner









Still have to figure out the WG mounting. The turbo bracket is temporary, using it for welding after I get the other side situated. Sure wish I had more time for my own build hehe.

Hopefully there will be time this weekend to get the other collector and turbo mocked up, but we are now up to 3 soccer practices a week O.O

 

Got a little more done today, creeping along...

 

Curious, why you made your manifolds that way? They look great.

 

Downpipes are going to go between the rear most primaries. Leaving the A/C components made a tight fit to get all the plumbing in there. Downpipes are going to go from the turbo to a 90* straigh down between the spread primaries, then to a 90* to the rear of the car as to meet up with the 3" exhaust.

Still got to stuff two 38mm wastegates in there somewhere too.

 

Will all accessories fit?

 

I'm converting to manual steering for now, and keeping A/C. Later on, I'm hoping I can fit a stripped down Siginaw pump with remote res in there somewhere.

 

fwd pump off a buick with the 3.8, they have remote resivors that are just cliped to the pump u can take the resivor off and put it anywere u like.

the pump is actually smaller then the pulley on it so its nice and compact

 

That's what I'm talking about It's called SiginawII IIRC, they are used in the 60* FWD 3x00's. All that needs to be done is the reservoir removed and a rolled tube pressed in. Summit sells them new and already moded for $100.