Patrick's Twin Turbo 350 Build Thread

Bad groove in that front cam bearing. Change it. You need to inspect the others . You may be fine

 

Good news! I finally sold my 1977 Lincoln last weekend, for $3300. Less than I wanted to get for it but about breaking even. Definitely enough to get this twin turbo project a financial kick in the rear! Ordering the camshaft/lifters/valve springs today if I can get ahold of Scott Brown.

 

Very cool. Send me a message if you need help getting a hold of Scotty.

 

To replace ALL the cam bearings properly, the engine HAS to be completely disassembled.
I have replaced cam bearings IN THE CAR, MINUS the rear, BUT its tricky, and only can be done if theres enough room to weasel the bearing thru the openings in the block atop the cam.
Im my blocks, the casting flash was removed during previous assembly.

 

Will do! He was supposed to call me last week but he never did.

I see! Well I'm fine just doing the front bearing if you think that will suffice for my build (stock rotating assembly, new cam/chain/gaskets/freeze plugs). The engine is on a rotating engine stand. I would remove the casting flash but I don't want to get any metal shavings on the crank. I'm not sure how to get a good look at the other cam bearings to see how they look?

I thought I could at least do the rear one by pushing it out towards the rear from the front of the block with my long cam bearing tool and then pressing the new one in the opposite way?

 

Twin turbos, intercooler, methanol/water injection, custom cam, fuel injection...for 400 horsepower?

Set your sights a little higher. This is like flushing dollar bills down the toilet.

 

Tell us how you really feel?

 

Can I get away with pushing more power than that on a stock block/rotating assembly? I'd love more power, but was trying to be realistic. According to Sean this kit made something like 422hp on 10psi and I think that was with forged pistons. I was planning on running this engine at 8psi while I save up to build another 350 or 455 block for much more boost (350 aluminum heads??), and build the car to handle the power. All while reusing parts that I already spent on the first time around. But I want to get it running this year if I can. Honestly I have no idea what this engine will put out. The more the better! Are you saying I should crank up the boost? How can I improve my plan?

True, with the $4000 or so (or more) I'm looking at spending when all said and done I could rebuild an NA 350 or even a 455. Hell a mule from AMP is only like $5000 right? But I also want to build something unique. I could cut a lot out of the budget if I ditched the EFI and got a Holley and did blow through mods to it, and ran no intercooler, etc. but wouldn't I end up wanting those things later anyways? I guess if I was really trying to just get the Skylark running I would have transplanted a SBC into it a long time ago. I think the coolness factor of a turbo Buick is half of what's motivating me to try forced induction. It's taking everything I have to not spend this money on my already running/driving car haha (Celica). I'm tired of the Skylark sitting in the garage . . .

I will most likely put the engine in the car after I break in the cam and run it NA for a while just so the car is drivable while I collect all of the turbo pieces.

Don't think that I'm trying to talk back here, I'm all ears if those with more experience can help me improve my plans! What do you suggest?

 

Another quick update, took a look at the other cam bearings with a flashlight today while I was in the garage. I was looking down through the lifter bores/valley area and none of the other bearings seem to have a groove like the front one, so I'm hoping I can get away with just doing the front. I will try and take some pictures of the bearings this weekend.

 

The front bearing would be the ONLY cam bearing with the wear groove.
Take a look at the cam journals, the front journal is the ONLY journal with the oil transfer groove, the front journal actually cuts into the bearing over time

 

Yes set your sights higher for HP, you should make WAAAAY over 400 HP with a turbo, heck, Im making over 400 HP naturally aspirated

 

And here I thought people would be telling me my engine would blow up If I can make enough power to beat my friend's 2018 turbo 718 Porsche (365HP) in a straight line, I'll be happy!

My Celica makes . . . about 90 HP. Switching between the 2 will be interesting.

 

Turbos make AWESOME torque..... from massive cylinder pressure.
The horsepower will come from trying to evacuate that pressure during the exhaust cycle.... the new aluminum heads should help with that
Boosted engines make impressive power at reasonable RPM, say 6000 rpm and lower.
Excessive RPM will kill rods, detonation will kill pistons/rings/bearings.
Excessive cylinder pressure will kill head gaskets.
Keep your tune safe, and you should be fine.

 

I'd also stay with the 350, never mind a 455.
Even tho the EFI and turbo/s you could swap over, the 455 is a bit more delicate than the 350

 

Yes, the tune will be very important when using Turbo or Procharge. I have seen too many Mustangs and others have the tune right on the floor but around town or at part throttle the motor is running lean.

Myself I like the Holley with the SP3, can get in car after sitting for 2 hours turn the key and it fires right up no gas needed, just like fuel injection, only mine seems to start faster than the modern stuff.

go figure

 

Mine too, I see no need for fuel injection.
Carbs being strictly mechanical in their operation are far more accurate than relying on electronics to activate and adjust injector pulses.

 

I see! I've read about people with blow thru carbs having to run very rich to prevent detonation and being unhappy with the tune at off boost, such as these:

https://www.hotrod.com/articles/bolt-on-efi-for-blow-through-applications/

https://www.theturboforums.com/threads/living-with-a-blow-thru.383459/

This is why I was leaning towards EFI. I wish I could go a step further and do a MPFI system in which I could tune each cylinder, sounds like the bees knees! Plus a good blow thru from C&S or whoever is like $800 already right? A Super Sniper 650 is $1200 plus fuel system . . .

 

Do port injection if you can.
Those ready to run EFI's are Throttle body injection, no better than a well tuned carb.
TBI (throttle body injection) is the most primitive form of fuel injection, the fuel still has to travel thru the intake manifold verses just the air in a port injected setup.

 

I would do a blow thru,...done properly it is hard to beat for stuff under 1500hp

 

The throttle body fuel injection may be "primitive" compared to the port F/I systems but they do better at air/fuel mixing like carbs do because they start mixing when the air enters like a carb.

The newer TBFI self learning power adder setups like the FiTech is $1,111;

https://fitechefi.com/products/30004/

Vs the $800 carb that will need to be dyno tuned to get the tune right so add another around $400 for the tuning, so about $1,200!

Of coarse with either setup the fuel delivery system will need to be upgraded so plus or minus $100 or $200 depending which way the OP decides to go with.

Those retro throttle body systems seem to work very well so I really don't see the down side using one, especially when they cost around 3 times less than a MPFI system. Plus the ease of setup compared to the MPFI as well, I don't think these are self learning so a dyno session would probably be in order here as well so add that to the cost.

The simplicity, ease of installation, reliability and the cost of the newer self learning TBFI systems are very hard to beat to make the same power with a MPFI system or even with a carb for a power adder engine like N02 or boosted setup.

Anyway that's the way I see it.