Patrick's Twin Turbo 350 Build Thread

Sorry for the hiatus! 350 is still sitting there with the SP3, oil pan, heads ect all installed. Basically just need to buy some ancillaries (dipstick, run stand stuff) and work up my courage. Here is text copied over from my to do list (to run the engine on the stand). As you can see I've worked through a good chunk: (underlined is finished)


-Vacuum crud off of crank etc.

-Replace rear main seal/main cap

-Replace all cam bearings

-Install cam dry, make sure it spins freely

-Install lubed cam (do not lube on first lobe!)

-Pull heads, find a way to protect bores from crud

-Clean/prep deck

-Degree cam/install timing chain

-Install new cam plug

-Final clean bores

-Install head studs

-Clean/Install heads, valves (with old hardware), block exhaust crossovers, Valve seals

-Check spare block or SP for windage tray

-Install pushrods/set valve lash (mark pushrods with paint)

-Lube and install new lifters, pushrods, lube distributor gear, lube fuel pump eccentric, LUBE CAM

-Install rebuilt timing cover and water pump (don’t forget oil slinger!)

-Re-lube the camshaft lobes through the lifter bores (slowly rotating engine to get maximum coverage)

-Bring engine to firing position (10 degrees BTDC)

-Re-lube the lifter faces with cam lube and the lifter bores with regular engine assembly lube

-Apply engine assembly lube to the pushrods, and cups on the lifters and rocker arms.

-Install lifters, pushrods, rockers

-Modify/install old valley pan

-Install intake/carb (make sure to install PCV grommet in intake first)

-Install balancer (add Speedi Sleeve)

-Install SRE oil pan and pickup

-Install windage tray/tap block for it

-Clean/paint block

-Modify valve covers for oil filler, PCV, and breather(s)

-Install dipstick

-Install small body distributor, spark plug wires

-Install misc (front accessories, motor mounts, pulley/hardware) from SP 350

-Install new freeze plugs (heads)

-Install fuel pump

-Move to run stand

-Mock up/build turbo oil feed/drain lines


After Engine is Assembled:


-Finish run stand

a. Weld supports

b. Add radiator

c. Add fuel cell

d. Add battery

e. Add gauges (oil, tach, temp)

f. Wire/plumb

g. Install throttle linkage/build throttle lever

h. Mock up coolant hose

i. Build temporary exhaust

Then it's break-in time!

 

Basically comes down to fuel delivery, the right amount at the right time

 

Post pics of your run stand, I've been curious about maybe buying (probably building) one.

 

This was because I was degreeing the cam and didn't want the lube to mess up my dial indicator readings. Don't worry I lubed the heck out of it after it was degreed!

Side note: I found that Comp Cams brand cam lube to basically fall off of the cam after a few hours, did NOT do a good job sticking to the lobes. I think I used Driven brand and it was much better. I do like the Comp Cam regular engine assembly lube, just not the cam specific one.

Will do! I'll try and snap some pictures of it tonight or tomorrow. I designed it to received the rotating head of your average engine stand to make it more compatible with other engines in the future.

 

Pictures of the run stand. Please forgive the welding, I built it over a period of about 5 years and while I'm not a great welder now, I was even worse back then! As mentioned above, I built it to mate with the rotating portion of a normal run stand. The supports are made with pieces I found at the local hardware (hinges?) with most everything else being fabricated out dimensional of mild steel. The fuel cell is a $30 eBay Jerry can that I welded a hose barb onto the bottom of. I made the stupid mistake of never painting it so it has a nice patina as well . . .

 

Looks good to me lets fire that Bad Boy up!

 

Nice job!!

 

Thanks guys! I can't wait to get it running. I'm so nervous about properly breaking in the camshaft, but I plan to make a video of the whole break in and post it here!

 

Just make sure you have enough cooling ability, mufflers so you can hear any noises from the engine, and oil pressure is established as soon as it fires, then rev it up

 

I Just finished my build. Cam break in seems to have went well. Wouldn't be too nervous. I ran it about 20 minutes at 1800rpm. I Used stage 1 springs during break in. I'm running the sp3, ported heads shaved .020, TA284-88h cam, and big headers. I'm dealing with carb issues but otherwise everything is good.

Your motor looks great. Mine was sitting on the stand just like yours last week. The adrenaline leading up to starting it was nuts.

 

Will do! Planning to run the exhaust through a pair of old Dynomax mufflers I have laying around.

I'm glad to hear your break in went well! I've been reading through your build thread too I have stage 1 springs but decided to leave the stockers on there for the break in just in case.

Besides getting the engine ready I've also been working on converting my Skylark from bench seat to buckets. I'm using a pair of seats I bought on craigslist a long time ago, I believe they are from an AMC eagle? I thought they looked cool and they are reclinable!

The plan is to weld custom mounts, using the stock mounting holes for the outside and weld to the floor on the inside. I want to build a "universal" type mount that will let me bolt in a racing seat if desired later down the road, but will also work for these AMC seats.

Here the seats are tack welded to my fabricated outside mounts, not mounted on the inside yet. I had my girlfriend and roommate both sit in it to verify that everything looked and felt straight. Must have tacked, cut, and repositioned 5 times by now but am finally happy with it.

Oh and I also finally got the T-Type wheel on with a new turn signal switch (my old one was flailing around uselessly).

 

Just be sure to vary the rpm between 1600-2200 RPM never leaving it at the same rpm, constant up and down to keep the wear pattern changing.

 

breaking in a cam sounds more scary than it is...
You know what you are doing, so do not worry

 

Everyone has their own method, as for me:
as soon as mine fired I got it up to 2500, spent about 5 minutes there, 5 at 2000, 5 at 3000, 5 at 2500, give or take one or two hundred rpm per 5 minute chunk. thats how i usually do it. keeping an eagle eye on temp and oil pressure. as well as scanning for leaks or things about to fly off.

Went well.

The main key is as said as soon as it runs get that thing upto rpm asap and shut er down the first signs of trouble, god forbid.

 

Small update! Sorry it's been going so damn slow. Finally getting the final few pieces of the run stand together:

Valve Covers/Breather Setup. Will allow me to run a screw on breather (I'm not a fan of the push-in type) and also AN lines to a catch can setup later for turbo:





Had to fabricate a baffle for the breather that would fit with the AN bulkhead fitting. First I used modeling clay from my local art store to check the clearance between the rockers. Looked like one side had lots of room but the other side was a bit close:





So I came up with an angled design to allow more clearance on on side. A lot of people may think this looks like an ineffective baffle but reading this article helped guide me and it seems having lots of room is a good thing to keep the air velocity down:

http://mewagner.com/?p=1221







Test fitting in valve cover with clay. I wasn’t able to get a wrench in there to hold the nut, but am able to get it tight enough by hand that I’m ok with it:









Finished welding and painted it:






Installed in valve cover. Was able to tighten it a bit better by wedging a piece of flat stock between the nut and baffle to stop it spinning. Fits well with room for rocker movement:

 

Next up on the list was mounting that radiator. I made 2 brackets for the bottom that connect to the stand and one for the top that connects to the intake manifold. Hopefully the engine won’t shake or wiggle too much and cause binding. I left lots of room in the brackets for movement and used weather stripping to cushion it. I love how this AFCO radiator has lots of mounting holes on top and bottom, made bracket fab easier. Will also make mounting it in the car easier as well.







Last up (for now) was building a throttle linkage. I used a simple lever system made out of flat steel:







It’s getting down to it! I can’t wait to finally fire this thing up! Still have to finish wiring it, get some little parts, and build the temporary exhaust.

 

Oh and a question, I have a rebuilt timing cover from UNDERDOG350 (thank you!) but it seems to use a different hold down for the distributor than my 1970 engine. Can anyone ID what year this is from so I can look for the correct part? My 1970 hold down doesn't fit at all.



EDIT:

Looks like this may work?

http://www.taperformance.com/proddetail.asp?prod=TA_1340

 

Pat, I ‘d say you are correct that the TA hold down will work with the timing cover. Engine looks great!

 

Well I called TA to order that distributor hold down but unfortunately it only fits Big Block Buicks. They told me people usually use a large washer as a hold down, but that's much too simple and easy for me! So today I set out to build one myself.

Had some 1/4” aluminum plate laying around that I hoped would work. Measuring the hold down flange of the distributor showed it was roughly 9/16” thick which would make 1/2” the perfect thickness for a hold down to be strong but still have that ~1/16” of clamping room.

I decided to make a 2-piece part. First I cut out the mounting flange, which I ground down to match the contours of the timing cover. I did the grinding after drilling the bolt hole as there wasn’t a great way for me to measure the hole spacing. This allowed me some wiggle room, so I could sneak up on the correct bolt fit. There is a flat tower cast into the timing cover that serves as a convenient reference edge. I also had to cut a small slot in the bottom with a file to clear another casting nub in the timing cover.







You can tell I've used this same 1/4" plate to make other parts before!

Once that part fit in place nicely I cut out my larger piece that will actually do the clamping. Found that a large spark plug socket was about the right size to use as a template for the flange on the distributor so I used that to trace the half-circle shape. I was using a porta-band clamped in a vice so I had to make a bunch of relief cuts to get a nice curve.







Once I had the pieces cut I did a lot of filing and grinding to ensure proper fit. Ended up cutting the back of the large piece down some. When I was sure everything fit together correctly I broke out the welder. It’s been forever since I welded aluminum and it shows, but the welds should to the job. You’ll notice I didn’t drill the bolt hole through the large piece yet, this was saved for last since it was easy to just continue the first hole once everything was welded. Sadly I'm no Steve Reynolds











Test mounted, and it works! Holds the distributor down firmly and looks a lot cleaner and stronger than a fender washer. I know the pictures make it look like I made the semi-circle too big, but there is a actually a larger OD ring built into the distributor shaft that the clamp is hiding.







I really liked the chamfers on the TA piece and how they give it that “billet” look, so I did my best to replicate them with files and a Dremel. Little bit of sanding and polish made it look less rough. If I had more patience I would really make it shine but it’s fine like this for now.





Final test fit:





One more thing to check off the list!