Darton sleeved 427 w/ L92 heads project begins
 

The dyno mule is getting a little tired so it's time to freshen it up. I thought about selling it and getting a C6 GS vert but I just can't justify the cost for a toy I drive 4-5k and year.

My engine was the first build in the country using the then new L92 heads. I wanted to see what could be done with the GM casting. Everyone poo poo'd the idea then but gradually came around. I've had 3 cams, stock and WCCH CNC'd heads of various compression ratios and other iterations. Everything that was done was done the make good power and keep the car very mild. The car currently makes 521/480 and drives very close to stock with massive tip in. 386RWT at 2200 RPM is nuts.

Here's the build thread from LS1tech:

http://www.ls1tech.com/forums/genera...us-plan-b.html

In talking with Shawn and Ed at Virginia Speed we decided that for the cost difference it made sense - if any can be made of any of this - to resleeve the LS2 block using Darton sleeves and increase the bore to 4.125. The only cost difference between staying a 403 and moving to a 427 is the cost of the sleeving which Shawn does in-house at VA Speed. I'll run the same crank, rods, cam, Melling oil pump, etc and top end. The extra bore will really make the L92 heads shine by unshrouding the valves.

I know Shawn and Ed will be posting pics and comments along the way. We're trying to make this an informative technical thread for those interested.

Shawn and Ed made the drive up from VA Beach this morning to pick up the cruiser. Damon (MCLEOD) came by to lend moral support. Next time I see it it will have a 427 under the hood.

Thanks guys.

http://i54.photobucket.com/albums/g9...10loading3.jpg

http://i54.photobucket.com/albums/g9...wnloading2.jpg

At least it was sunny.. :)

http://i54.photobucket.com/albums/g9...0ontrailer.jpg

On it's way to winter in Va Beach - again. :yesnod:

http://i54.photobucket.com/albums/g9...D/IMGP2089.jpg

Best of luck. Beautiful car. It matches the snow.
:bigears

Good luck. I would love it if Shawn posted photo's of the machining process as it progresses and the block is transformed.

:sadangel: I would have came down just to counter bid McLeod's used parts dream list :leaving:

Another excellent adventure (said in my best, "Bill and Ted" movie voice)! I'm looking forward to following your new 427 engine build thread with pics and seeing the results of this new TORQUE MONSTER!

Anyone need any stumps pulled? :lol:

There is another cost that you omitted, that of pistons fwiw. :)

Looking forward to seeing what it will do!

Kevin, what pistons are you going with and what is the targeted compression on this 427?

Should definately pick up a decent amount of hp man. Best of luck on the new project.

Shawn told me he's using -8cc pistons which will net approximately the same CR I'm running now with the -2cc pistons on the 4.005 bore.

BTW: I just had a long talk with Richard at WCCH (proheads.com). He's been fine tuning his port program for the L92/LS3 heads and doing some work on the chamber. He has the intake ports flowing 380CFM of great quality air with excellent low and mid lift numbers.. He said the heads should be very comparable to LS7 heads when we get them back. He's putting in a 2.200" intake valve. :smiliedrool: He's really excited to be involved with this ongoing project again. We're excited he's involved also. :thumbs:

Sonofabitch! What bore size/valve size/lift is that cylinder head flow at?

Thats some good info Kevin, thanks for sharing. So if the heads will flow 380 cfm, how much does that intake of yours flow ? I know the 4 inch tube up front is not going to be the restriction, I'm wondering if the intake is going to be it though?

I know Richard usually flows at 4.030 and a 4.155. I'm not sure which bore he used but I believe he told me a .650 lift. I run a little more lift than that on the intake with the current cam.

The intake will remain the limiting factor. I really wished the LSx performed better on these heads.

Maybe a vendor who is stuck with an LSx intake could offer one up for a test with the reworked heads.

Working on it. :D

I should have known.:crazy:

I'm guessing that's gotta be at 4.155", but still that is a LOT of air!

:cool:...............That is all..............Carry on............... :leaving:

Thanks for sharing...keep coming back. :rofl:

Is ITB an option ??

Ed just did the last pull on the 403. 516/472 without any tuning for temp, etc. No question in my mind he could make a few tune tweaks to do 521/480 which it was last spring. This build has aways been extremely consistent. Well, now we have a baseline. Onwards and upwards!

Are you offering to give me one??? :)

Awesome project. Can't wait to see how this progresses.

Im watching this as well! i really want a 427 in my Z. After my recent cam install at VA speed i am loud and choppy a year or two of this and ill want a true sleeper.

I will drive it back to you when its done to assist with the break in for gas and beer if you need me to!

Mario

Now that I see the new numbers and the old spring numbers, I could clearly see what you mean by motor being tired :willy::willy:

Somebody just wants to put Joe's stump removal service out of business.

The day I hit the lottery Kevin, you got it.

Ed says that if he just let the oil heat up he would have pulled the old numbers.

I think the new build will make a little more. :D

Will there be a pool for what the new numbers will be? :lol: I'll say 585/530.:eek:

:lurk:

You know he wont be happy unless he's 600/600 NA. :crazy:

I really have no idea where we'll end up. This remains a science experiment. I would hope 550/510 but who knows. We'll ALL just have to wait and see.

:lurk: Listening and learning :cheers:

Where did the motor leak?

Intake, exhaust, crankcase?

:willy::willy:

:willy::willy::willy::willy:

At least SOMEONE is thinking realistically here. :leaving:

We'll be cam and intake limited here. We're contemplating several "options" but won't make any changes until we have a complete motor baselined in it's current form.

All in the crankcase. Had several cyl. as high as 30% down.

That answers that question. Thought I might be able to save some unneccesary bottom end work. Let the build proceed! :thumbs:

Well, thanks. :crazy:

Not that you need my permission! lol :o

But it's nice to have your blessing LOL. :lol: :thumbs:

Nice guess. This is not your first rodeo, so you know the dyno can break your heart if numbers are all your concerned about. I would still guess a little higher. I'm thinking at least 520rwtq using that same cam!


Subscribing....

Shawn sent some pics last night. The drive train is out and dissasembly begins.

The always photogenic Ed.

http://i54.photobucket.com/albums/g9...003EDINCAR.jpg

Doing one last baseline pull on the 403. They use an in-ground DynoJet - also known as the "Heartbreaker". The numbers were down less than 2% of last spring. No adjustments of any kind were made. It's always been extremely consistent.

http://i54.photobucket.com/albums/g9...02DYNOPULL.jpg

Next it's up on the lift. A keen eye will spot the LG GT2 coilovers and PFADT sway bars.

http://i54.photobucket.com/albums/g9...0004ONLIFT.jpg

Everything unbolted and unplugged and the car is raised off the drive train.

http://i54.photobucket.com/albums/g9...1-12-10011.jpg
http://i54.photobucket.com/albums/g9...1-12-10014.jpg

I run an ECS tranny brace with an RPM 3.90 rear.

http://i54.photobucket.com/albums/g9...VETRAINOUT.jpg

I change the oil very frequently - everytime I have the motor out.
http://i54.photobucket.com/albums/g9...RAININGOIL.jpg

So long to the 403.
http://i54.photobucket.com/albums/g9...1-12-10020.jpg


Shawn will be sending more pics of the dissasembly, parts for the new build, machine work and assembly. We'll post the progress and build results all the way until I pick it up with the 427.

while the drivetrain is down, are you gonna change the TT bushings again. You know you beat them up

Great pics !!! I remember the first time I saw my car like that. I was in disbelief. Amazing how easy everything comes out and goes back in with a lift.

Question on the couplers. Are you running stockers, or do you have 1 stock and one solid? I have a solid coupler in the rear, stock up front.

I run BMW couplers front and rear.

Whats the advantage with BMW couplers vs gm stockers ?

None. Same part.

Got it.

Probably a good time to upgrade to 2001 and later torque tube to handle the increased power and torque.

Lots of $$$ for a few more ponies over what you had. Why rebuild ?

It's pretty tired with a LOT of leakdown - 25-30% on a few and I wanted to replace the clutch anyways.

I'm fortunate that I had a very good business year so I get to do some things I want to. Not any more complicated than that.

Glad business was good for you. :thumbs:

How many miles did you have on that motor ? Kind of curious as to why you're having cylinder leakage since the motor is not that old.

BTW, question about the rebuild was more about why than $$$, just was curious since you're weren't doing FI which seems to be the most prevalent reason.

The 403 has about 16-18k miles on it. This motor has generated a lot of crankcase pressure since day one. We've done a huge amount of L92 R&D on it and the leak-down is now 25-30% on a few cylinders and 15-20% on a few more. It's time I do something. For the cost of the liners I can take a freshening of the motor to a solid 427 build. I like the challenge of making good power NA. If I was a gross power guy, of course it would FI of some sort..

Like I've been saying for the past 3 years - this is an ongoing science experiment. I've been know to take the road less travelled more than a few times in my life. :)

Hi Kevin,

I too have followed the road a less traveled a few times with my blue coupe project car, so I know that road. :rofl:

I had followed your build over on LS1tech and here since yours was one of the earlier builds. I'll be interested to know what caused the huge cylinder pressure differences ?

:cheers:
Tony

Did you leak it when it was fresh? It would be interesting to see leakdown vs. time.

Have the shop check the rings on the pistons they pull out. If the edges are sharp on the rings, they're done.

On the very first head and cam swap (way back when) the leakdown was pretty severe for the age and mileage of the motor.

When I first met Kevin, we both stood and watched as his car was run on a dyno. This must have been 06 or so. We both commented on the amount of blow by coming from the VC vent. It was practically brand new then.

Venting the crankcase without puking oil all over the place has always been a challenge. I've had it under control for a long time but early on I must have gone through a half dozen iterations.

And what do you mean by "one of the first"??? This was the first :yesnod:

BTW: I've followed your build and it's been very interesting as well. You're probably like me when someone says there is only one way to do something - I do it the other way. :thumbs:

Shawn has the engine torn down and PM'd me this afternoon.

A couple things,measured your bores smallest part of the smallest bore is 4.0050

largest part of the largest bore is 4.0085-that's .0035 difference.Some bore had as much as .0025 taper and out of round-pretty much like every other SDxx engine.The pistons were 4.0005-so you had as much as .008 piston to wall clearance.
I'll send you some picks tonight but you can see where the main caps were walking around due to the stock main bolts.

I'm very confident that when I get it back you won't see those kinds of tolerances.

No wonder it didn't make any power. :crazy:

^ Wow, that's a lot of wear or someone did a real bad job of measuring the bore and choose the wrong piston size.

I would not have expected that much oblonging of the cylinders since you're not really over-stroked. I see a bunch of other 4" strokers that do not seem to suffer this kind of problem.

Wondering if an iron block would fair better than an aluminum block for this type of configuration.

I'm not thinking it's all wear. :ack:

Curious if you bought the 403 short block?

Also, don't know too much about the Darton sleeves and installation process so I am hoping for lots of photo's from Va Speed. How is the street reliability of this type of approach?

The short block came from SDPC. The Darton sleeves are much harder than the stock sleeves. They are also longer for better piston support at BDC. It will be more reliable than the stock block and sleeves.

We'll be posting lot's more pics.

All broken down:

http://i54.photobucket.com/albums/g9...upsidedown.jpg

Looks like it was burning some oil after all. Good shot of the tie-bar lifters.

http://i54.photobucket.com/albums/g9...upheadsoff.jpg

Pistons and rods out.
http://i54.photobucket.com/albums/g9...ginewcrank.jpg

You can see where all of the main caps were walking with stock bolts. For some reason I thought I had ARP mains.

http://i54.photobucket.com/albums/g9...D/maincap1.jpg
http://i54.photobucket.com/albums/g9...D/maincap2.jpg
http://i54.photobucket.com/albums/g9...maincap3-1.jpg
http://i54.photobucket.com/albums/g9...D/maincap4.jpg

16-18k on this LS2 chain. Being replaced with a Cloyes adjustable setup.

http://i54.photobucket.com/albums/g9...mingchain1.jpg
http://i54.photobucket.com/albums/g9...mingchain2.jpg

Bare block ready for some serious machine work.

http://i54.photobucket.com/albums/g9.../bareblock.jpg

Nice work

Sweeeeeet :thumbs:

Nice. :cheers:

Question: I notice what appears to be an LS1 style knock sensor on the side of the block. Do you plan to change to the LS2 style when the engine is finished?

I have heard (unconfirmed of course) that possibly some of the earlier LS1 KS's were not nearly as good as the later versions or the LS2 type. Other than the obvious design/mounting difference between the LS1 type and the LS2 type, do you know of any actual performance differences? A pro/cons on this?

I've had these knock sensors mounted on the back of the heads and on the sides of the blocks without any problems in either location. They work fine and I've never had a false knock issue.

I just heard from Shawn.....

Sleeves going it today. :party::party:

Jeez these guys are moving fast.

VA. Speed has an impressive in house facility.:cool:

I'm certainly no expert at inspecting engine mains......how can you determine by the appearance of the cap that it was walking?

Wow, I chimed in late as hell on this one. I've been out of town going on 2 weeks now. Still gone but just now getting on the forum.

Kevin! I am proud! You'd better take me for a ride in that beast when you get her back :)

I didn't read through the thread, just looked at the pictures.. when do you plan on having it back?

Wow, pretty interesting shots of the main caps moving on you, thanks for posting.

Were you the guy at ECS getting your coil overs put on while I was having my black vert street tuned?

You can see the high/low spots and the transfer of metal as opposed to a freshly machined look.

Yep, that is clear. What isn't clear is why the wear would be in an arc. I would expect the disparity to be linear.

Maybe the mill tooling marks when the caps/block were machined were in an arc? I'm not an expert, I just know a little bit. I'll ask my machine shop guy next time I talk to him.

That's what I was thinking. Photo's of this kind of thing are hard to take as well.

I would expect it to done in 3-4 weeks. We'll get together. :thumbs:

Nope. My coilovers went on in my garage with the help of some forum friends.

After hearing the explanation, I think the presence of "high"/"low" spots, as indicated by "clean" metal vs "dirty". (Actually I guess it's not "dirt" as such, but rather the presence of motor oil, etc).

The small areas of "clean" or burnished metal are just visible in various places. One example is the area directly around the bolt holes where, upon torquing down the caps, the metal directly around the bolt holes is being "stretched" slightly as the bolt pulls upward on the block and the aluminum block material becomes "burnished" against the steel main cap from vibration/movement over time.

I'm thinking that the "arc" visible in the pics were actually from the original machining of the surface and are (in this case) made more visible by the "dirty" oil at the microscopic level when opened back up. The "movement" is so slight, probably on the order of .0001 or so (or in that range), maybe less, that there would not be a discernible "direction" pattern as such. I guess the thrust forces are being applied in a more random or even circular manner, i.e. front-back, side-to-side, depending on applied power and rpm, etc. Interesting.

Hope that makes sense, cause even if it doesn't, that's my story and I'm sticking to it. :rofl:

Sounds good brother. You've got my number.

You really can't see the fretting in those pictures.The fretting from cap walk is actually metal transfer from one surface to the other.The arcs are from the block machining.

I got some good machining pic over on LS1Tech-i'll post them over here tomorrow night

:lurk:

hmmmm....

:confused:

Hey shawn, i sent you a PM.. still waiting for a reply

Maybe if we all PM'd Shawn at the same time he'd post some more great pics. :D :rofl:

nice progress kevin! Good reading here. SDxx? Scoogin Dickey?

You thinking of another caravan to pick your car up? I would be up for that if it's decent out. I'd like to check out that facility also.

Sweet, will be fun and informative watching this thread. thanks

or he might go to bed:)

Here are some pics of the sleeve machining and installation process.


http://i256.photobucket.com/albums/h...1-14-10025.jpg

first thing is the block setup in the cnc-here the probe is finding the crankshaft center line


http://i256.photobucket.com/albums/h...1-14-10026.jpg

now we find the camshaft centerline-this way we ensure the bores and decks are exactly 45 deg from the camshaft to crankshaft centerline


http://i256.photobucket.com/albums/h...1-14-10028.jpg

now we probe the bore locations to determine the location of the bores


http://i256.photobucket.com/albums/h...1-14-10030.jpg

now we probe the decks in 6 locations on each bank-this tells us the height and straightness of the decks


http://i256.photobucket.com/albums/h...1-14-10034.jpg

here is a report of the locations of the bores and the deck heights-the x locations in parenthesis are the blueprint locations the one beside them are actual.All y locations should be zero


http://i256.photobucket.com/albums/h...1-14-10035.jpg

here we are rough boring-this will get us to within .020 of the actual size


http://i256.photobucket.com/albums/h...1-14-10037.jpg

block after rough boring


http://i256.photobucket.com/albums/h...1-14-10039.jpg

couple shavings underneath


http://i256.photobucket.com/albums/h...1-14-10040.jpg

finish boring-we need to be within .0002 when finish boring-that's 2 ten thousanth's of an inch.Accuracy is really the key here-if not bored perfectly-you can crack the block when installing the sleeve or you can have a loose sleeve.There are not too many machines out there that can hold this accuracy-we are very fortunate to have one.


http://i256.photobucket.com/albums/h...1-14-10042.jpg

bores ready for sleeves


http://i256.photobucket.com/albums/h...1-14-10043.jpg

sleeves installed


http://i256.photobucket.com/albums/h...1-14-10045.jpg

ready for final machining

here is the block decked to the proper height-give or take .0001:D

hopefully next week i can get the block honed and rotating asy balanced-i got a lot of other blocks to hone as well

http://i256.photobucket.com/albums/h...1-15-10001.jpg

http://i256.photobucket.com/albums/h...1-15-10002.jpg

http://i256.photobucket.com/albums/h...1-15-10003.jpg

SDxx=Correct!

I've got a few guys want to make the trip. I'll count you in Steve. Follow the thread and you'll know when we're going down.

I love these pics!!!! :party::party::party:

That is some beautiful engine porn there! Kevin, looks like the guys are doing some 1st class work on your project. Looking forward to our road trip to VA Speed when ready.

Engine porn :party::party::party::party:

good job VA Speed...you and I know youre in good hands with them!

Round and flat is good! All of the machining within .0001 is :cool:

So Im hanging out with one of my kids this morning watching saturday morning cartoons, and I ask him " do you remember Kevin with the white corvette from Virginia". She says "yes". I say "look at these pictures. He's having a new 427 motor built" he looks at the pictures and says" is that good". I say " it will be good for a while tell kevin says it need more" :rofl:

Kids lol

LOL I gues the heads will be boxed up and shipped to Richard at WCCH (proheads.com)this week for his treatments. This is moving quickly but I think it will slow down a little now.

It's all good. :thumbs:

I wonder how it would run with a little boost...:crazy::willy:

Oh boy.:willy:

Great pictures and details. Didn't know VA Speed had all of that fancy equipment.