Patrick's Twin Turbo 350 Build Thread

Interesting to see all the differing opinions! For reference, this is the unit I'm currently planning around:

https://www.holley.com/products/fue...sniper_efi/sniper_4bbl_tbi_kits/parts/550-518

Similar to the FiTech unit. Planning on a Tanks Inc. setup for fuel but we'll see. Also considering a RobbMC Power Surge.

I believe I found a way to finally get a hold of Scott Brown, will attempt tomorrow!

 

https://www.summitracing.com/parts/...4KrWazVMJmlJU5n3LNXk_joOuEtvQhX0-bhoCSBDw_wcB

I went with a setup like this in my Skylark. Pricey, but it is a clean setup and the pump is whisper quiet. It would support quite a bit of power even on E-85.

 

Have you had any fuel starvation issues while launching or cornering with the Stealth tank?

 

It's a baffled tank with a submerged pump, far superior to any external pump fuel system in regards to fuel starvation,...the new Holley tank set up is a little cheaper

 

I've read a few complaints about the Tanks Inc setup regarding fuel starvation even though it's a baffled in tank setup as well. I guess all are not created equal?
Fuel starvation is one thing I absolutely do not want to have be a problem with this build!

 

That tanks inc tray isn't large enough,..the Holley and Aeromotive has a much larger tray

 

Gotcha. The Holley Sniper tank is cheaper than the Automotive but I wonder if the 255 lph pump would be enough? Supports 550hp NA on EFI. What are your thoughts on the PowerSurge:

https://www.robbmcperformance.com/products/powersurge.html

 

It wouldn't be my choice,..you can up grade to a 340lph for just a few bucks more iirc

 

Turbo cam, lifters, and springs ordered from Scott Brown! Will post a budget update once the damage hits.

 

Specs on the cam? Flat tappet?

 

Did you have to call his mom?

 

Cam card attached (actually it's a picture from your thread of your cam haha). After talking to Scott this is what he recommended. It's a flat tappet but I paid a little extra to have it nitrided.

Haha almost, Sean was kind enough to provide me his cell

 

Just got the email from Scott that my cam is done and ready to ship! I'm working on getting my garage cleaned and organized in preparation for pulling the heads off to send out and installing/degreeing the cam. Also that cam bearing. Will be placing a rather large TA order soon.

 

What are you having done to the heads?

 

Well that's the question! I was originally planning to take them to a local machine shop and ask for a budget rebuild using TA's oversize valves (they don't make standard size?). Hoping to spend about $500 not including parts. However I just got a quote from Mike over at AMP for $1160 (not including shipping) to do the following (invoice attached).

Is it worth the $$$ to have Mike work on them? I would feel much better about using AMP seeing as they are Buick specialists and seem to do high quality work. But do I really need to get the heads rebuilt in the first place if the engine was making good compression? I could just slap some new head gaskets and head studs on it and run it as is. Would I end up regretting that?

I know the TA 350 aluminum heads are supposed to drop any minute now, but aren't they going to cost like $3000? I guess I could try and save now by not doing the heads and then buy aluminum later?

I need some advice before I go spending any $$$!

 

Since your turbo charging, and are going to have the benefit of a turbo cramming the air and fuel in, head work is not as critical as in a N/A engine.
Id have a standard valve job done, nothing fancy.
Don't get me wrong, fancy head work WILL increase the efficiency of the turbo, and engine output, but its not a requirement for boosted engines.

 

They need to be at least freshened,..boost will push by weak guides,..barely sealing valves etc

Here's how I would look at it
1. Iron heads limited to around 12~14lbs with 93octane provided its around 9.0 to 1 maybe less depending on cam timing
2. Iron heads and meth injection will allow close to 20lbs
3. Meth and a FMI will allow enough to find out just how strong the 350 is
4.ported irons /worked irons will allow similar power levels at less boost,..no more than the 350 head can be made to flow,..I'd estimate around 2 to 5 less boost to equal the same power
5. Aluminum heads will allow more boost in all situations and would really be worth there most in a pump gas hot air situation

I'm just one of the many fellas that have ran a stock GN longblock into 10's with iron heads and 93 octane,..it takes meth,..good intercooler,..plenty of fuel,..and,..25+lbs of boost.
The 350 is the same boresize,..just with the open chamber head so it may react a touch different but I cant imagine it being much

 

I would just have a local shop freshen you’re heads with stock valves and save $ for the alum heads. Yes they are expensive but it’s better than spending big $ on irons. The alum heads can Be ordered now and they do a layaway plan.

 

How long before the Chinese are producing alloy heads for Buick as cheaply as they are for the rest of the mainstream engines?
Guess we aren't mainstream enough though.

 

Thanks for the advice guys! Sounds like a cheaper "refresh" is going to be the plan. Does that mean reusing the stock valves, or buying new stock size valves from someone like Rockauto? In your experience does it help to show up to a machine shop with parts like valves, springs, valve seals, seats, guides, etc in hand?

I will ask TA about layaway when I place my parts order!