Great White Buffalo (first post)

[termite]

Looks cooked into leather not just well done.

Full tear down in order soon?

Side note: Does your upper radiator hose have a support bracket?

 

[Erik the Awful]

Glue a dime on the end and put it back on the road!

Just kidding, please don't do that.

 

[Great White Buffalo]

Haven't dropped the oil pan yet or cut open the filter, but no sparkles whatsoever in the oil that I drained. I fully expecting glitter. I would imagine a full tear is probably on the docket, but I think until I get time for that I'm just going to keep pulling it apart a step at a time. I'm going to try and get the heads off today, maybe the oil pan if time and ambition permit. I'd love to find an intact piece of lifter in the bottom of the pan.

 

[Scooterwrench]

I had a 79 Malibu with a 229 V6 that sheared a cam lobe and all that was in the pan was the lobe off the cam. I was sooo happy!!!,gave me the excuse to build a 355 for it.

 

[Great White Buffalo]

Well I finally got around to pulling the engine. Haven't had a chance to dive in yet, but I will say the cylinder bores are in great shape. The engine only has about 110k miles on it. I'm hoping for a quick turn around on getting it back in. I'll try to update as I go. I don't get a lot of time to work on it so this won't be the most exiting (re)build. Biggest thing right now is picking out a new cam. The obvious answer after wiping out a flat tappet cam is roller, but I'm open to recommendations. Is there some contingent of flat tappers out there that have some tried and true method of break in? I'm currently looking at a comp 218/224 (XR270HR). I think I'd like to find something with a greater LSA than 110 for my idle quality. The flat tappet I wiped out was a comp 212/218 (XE256H) on a 110 LSA and it's idle, while it was still living, could've been a little smoother. I'd like to not have to change out the torque converter also. I've also been looking at some howard's grinds. I'm open to idea's and opinions on camshafts. Depending on how the rebuild and install go time wise I planning on doing the turbo set up as well.

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[Scooterwrench]

If you go with flat tappet the break in is fire the engine up and run it at 1800-2000 for a 1/2 hour. Running it at that speed keeps plenty of oil slung up on it off the crank. Let the engine cool completely then do it again two more times. This also heat cycles the rings. Use high zinc oil on flat tappet cams. Roller cams don't really need a break in period but the rings still need to be heat cycled.

 

[Road Trip]

Well I finally got around to pulling the engine. Haven't had a chance to dive in yet, but I will say the cylinder bores are in great shape. The engine only has about 110k miles on it. I'm hoping for a quick turn around on getting it back in. I'll try to update as I go. I don't get a lot of time to work on it so this won't be the most exiting (re)build. Biggest thing right now is picking out a new cam. The obvious answer after wiping out a flat tappet cam is roller, but I'm open to recommendations. Is there some contingent of flat tappers out there that have some tried and true method of break in? I'm currently looking at a comp 218/224 (XR270HR). I think I'd like to find something with a greater LSA than 110 for my idle quality. The flat tappet I wiped out was a comp 212/218 (XE256H) on a 110 LSA and it's idle, while it was still living, could've been a little smoother. I'd like to not have to change out the torque converter also. I've also been looking at some howard's grinds. I'm open to idea's and opinions on camshafts. Depending on how the rebuild and install go time wise I planning on doing the turbo set up as well.

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So glad that you have broken radio silence with this status update!

I was really hoping to live vicariously through your towing-oriented
turbo 496ci build...so I was disappointed when it seemed like the project
went silent, as if it had to be shelved for some unknown reason.
(Life happens, been there, done that.)

From over here, I'm thinking that a cam choice for optimized torque
production in your towing RPM band (ie: getting the DCR as close
to the limit that the octane rating of the gas you plan to use will
support) would be the plan.

If you were to do this along with the matching L29 torque-oriented
intake + the 496ci displacement should be a pure pleasure. And then to
seal the deal, you would size the turbo so that A) it didn't push the
motor into detonation in it's NA powerband, but instead B) blows
the powerplant up towards a sparkling finish once the cam/intake
combo starts to fall off. Does this make sense?

The idea is to draw a line where the 87/89/91 octane fuel can
support power production without risking detonation. And
where the cylinder pressures inevitably drop off at the upper
end of the torque curve (3500-4000 rpm?) then the turbo has
spooled up and all that NA nonsense is overcome.

Done correctly, you could definitely dial up many, many ft/lbs
of torque *and* also enjoy a rewarding driving experience
behind the wheel.

I'm all for this, for torque to a GMT400 machine is like accurate
deep bass for a home theater/serious music appreciation. You don't
realize how much it makes everything better until you experience
the real deal.

Great White Buffalo, indeed. This is truly exciting stuff.

 

[Great White Buffalo]

So glad that you have broken radio silence with this status update!

I was really hoping to live vicariously through your towing-oriented
turbo 496ci build...so I was disappointed when it seemed like the project
went silent, as if it had to be shelved for some unknown reason.
(Life happens, been there, done that.)

From over here, I'm thinking that a cam choice for optimized torque
production in your towing RPM band (ie: getting the DCR as close
to the limit that the octane rating of the gas you plan to use will
support) would be the plan.

If you were to do this along with the matching L29 torque-oriented
intake + the 496ci displacement should be a pure pleasure. And then to
seal the deal, you would size the turbo so that A) it didn't push the
motor into detonation in it's NA powerband, but instead B) blows
the powerplant up towards a sparkling finish once the cam/intake
combo starts to fall off. Does this make sense?

The idea is to draw a line where the 87/89/91 octane fuel can
support power production without risking detonation. And
where the cylinder pressures inevitably drop off at the upper
end of the torque curve (3500-4000 rpm?) then the turbo has
spooled up and all that NA nonsense is overcome.

Done correctly, you could definitely dial up many, many ft/lbs
of torque *and* also enjoy a rewarding driving experience
behind the wheel.

I'm all for this, for torque to a GMT400 machine is like deep
bass for a home theater/serious music appreciation. You don't
realize how much it makes everything better until you experience
the real deal.

Great White Buffalo, indeed. This is truly exciting stuff.

Thank you, this does make sense. Now that I have the engine out I can spend some time dialing everything in like it's compression ratio. Off the cuff, and with the smaller combustion chambers of the gen 6 heads I figure it's somewhere in the low 9's. I talked to someone at comp a little while back that pushed me to the larger 218/224 from 212/218 I was planning strictly based on a +9cr. The end goal is to keep it pump gas (91). I'm hoping smaller cam, low boost (5-6lbs), intercooler, and conservative timing helps me achieve that.
Waiting on the stroker is a bummer, but since I started this project a couple of years ago I added another kid (that hasn't been cheap) and as of a couple week ago, need a new transmission in 06 yukon. The 4l65 finally gave up. I briefly considered swapping the 4l80 from the buffalo to the yukon, then going forward with my nv4500 swap. It would fast forward my mt swap plans for the buffalo sooner than I planned on, but I'd only be buying one transmission. The biggest deterrent to that plan, beyond my lack of 4l80 swap knowledge, is my track record with projects. I'm not known for my speed in which I complete them. So the stroker stays on the back burner for now...

 

[Great White Buffalo]

If you go with flat tappet the break in is fire the engine up and run it at 1800-2000 for a 1/2 hour. Running it at that speed keeps plenty of oil slung up on it off the crank. Let the engine cool completely then do it again two more times. This also heat cycles the rings. Use high zinc oil on flat tappet cams. Roller cams don't really need a break in period but the rings still need to be heat cycled.

I did the initial break in when I put the last cam in. I ran it at 2000-2200 for about 25-30 minutes. I don't think my neighbors appreciated it all that much. I had just finished the exhaust and the buffalo's not what you'd call quiet. There's nothing quite like the rumble of a big block Chevy through dual 3" pipes. I did not however heat cycle it twice. Truthfully, I felt like I got a good break in on it. It ran pretty good after, and though I had other issues that arose, it ran pretty good up until it ate the lifter.
I wouldn't be opposed to another flat tappet, the cost difference alone makes them hard to say no to. I was looking at comps dlc lifters and am intrigued, but have no experience with them. Any idea if they're worth it or is it just a gimmick. Thanks for the help

 

[Sean Buick 76]

Such a cool project! I’ve done a lot of turbo stuff so feel free to reach out to me if you need advice.