Lessons Learned from a motor swap

L K meano biker · Posted: Mon Aug 13, 2007 7:15 pm Post subject: Lessons Learned from a motor swap

I recently swapped the 305 out for a fresh 350, not without several headaches. Hopefully someone will read this and get something useful or helpful to them from it. My Camino is my daily driver and I am not looking to make it into another trailer queen or a 1/4 mile shredder, just dependable daily transportation with a few nice bells and whistles.
I initially started with a complete GM Goodwrench 350 salvaged from a 1996 Caprice Station Wagon- $150.00 from work.
I then took the motor to a local machine shop for disassembly and inspection. One rod was slightly bent- probably the result of vapor lock (water in engine); however the cylinder from the bent rod was practically unscathed. The top end already had a billet roller cam, I was given a price of $1300 to clean up, rebuild and reassemble. I then gave myself a budget of an additional $3500 to buy some performance goodies, have the motor swapped, and have some left over to get the rear end redone and some transmission work (trick shift and convertor lockup switch) and maybe enough to get my new doors, fenders, tailgate primered black
I figured on reusing the flywheel, starter, A/C compressor, oil press and water temp senders from my 305 and also figured that the swap would be a piece of cake since the 305 and 350 are very similar. So I shopped, got everything I could possibly think of, new motor mounts, plugs, wires, power steering hoses, etc.-roughly $2100.00
Took it to a reliable mechanic for the swap- $1400.00 more, now am way over budget

Lesson 1- even though I thought I had planned well it wasn't good enough (Murphy's Law of auto repairs and rebuilds)
Lesson 2- most timing covers are not sold with a timing tab- needed unless you want your mechanic to use a paint pen to mark on your newly painted block for a timing reference
Lesson 3- flexalite fans SUCK!! sure they sound like a blower, but even with grade 5 bolts properly torqued and threadlocked mine managed to use the spacer to shear the bolts, send the fan into my radiator shredding it into 6 pieces, sending the pulley under my truck and through the windshield of the vehicle behind me (less than 600 mi on the motor)- cost, new radiator, fan and clutch assembly, labor, and probably higher insurance rates
Lesson 4- you can't always belive everything you hear, OR read on the internet- the PYPES exhaust kit, supposedly "bolt-on" with basic hand tools- I wrestled this exhaust for 2 solid days, still have to take the truck to a muffler shop to slightly mandrel "s" bend a piece so it lines up with the header collector and take off the pressure I put on the header from ratchet strapping it into place
Lesson 5- see first part of lesson 4- tried to by a 3.73 ratio speedo adaptor from Dixie Monte Carlo Depot for my 7.5 in rear end, guy says you don't need it for an 87, last weekend swapped the rear end parts out- 28 spline axles from a Buick GN, with factory 3.73 gears and a factory GM Eaton posi unit from a Monte Carlo SS, now at 50 mph my speedo is pegged
Lesson 6- installing a 350 without changing the rear end gears is senseless, the difference between the 2 something gear and the 3.73 with posi is almost like having a new tranny, much quicker shifts, it all seems to "hook up" like its supposed to now, plus I get to leave 2 tire marks now instead of one

So I have overblown the budget, doors, fenders, and tailgate primer and installation will have to wait, but am very happy thusfar and would probably not do anything different (except the timing tab and fan)
For those curious you can see my current progress pics here:
Front Side profile
Engine 1
Engine 2
rear end view

1BadElky · Posted: Mon Aug 13, 2007 7:26 pm Post subject:

Well sorry to hear about your bad experience. Why would an aftermarket timing cover not have a tab? That's just retarded! I hadn't thought about that yet, so I'm glad somebody mentioned it.
_________________

Formerly 86Conquista

Currently undergoing resto.
Planned:
-350/?/3.42
-ZQ8 wheels
-Disc Brakes
-More

L K meano biker · Posted: Mon Aug 13, 2007 8:18 pm Post subject:

I could have dealt with everything except the fan ordeal, that was kind of scary, the guy behind me swerved to miss the pulley, he also had a trailer hooked to the back of his van which also fishtailed causing several other cars to run off into the grass. I felt pretty dumb asking him could I get my pulley from his front passenger seat, especially since it went through his windshield to end up there.

Anyway, the timing cover was a GM performance parts, black crinkle finish with red logos, and I too thought it would have come with the tab

theelcaminofactory · Posted: Tue Aug 14, 2007 9:21 am Post subject:

Aftermarket timing covers don't come with timing tabs because of the different sized balancers, you have to bolt on the tab to fit the size balancer you have...one size does not fit all. Geez even a 90 year old Chinaman living in the back bamboo fields along the Yankme River in Pyong Woo Province would know that...OK just kidding, I found out the same way you did too!

bigjames4xl · Posted: Tue Aug 14, 2007 3:08 pm Post subject:

Yep, lots of pitfalls when changing/upgrading engines!!! BUT, you did a good thing by allowing a reasonable budget from the start, and, even though you spent more than you planned you should be done now!!! No used engine blues or corner cutting "on the cheap" moves to leave you parked, just some "teething problems" to work out and you are up and running!!! Cool

You are way ahead of the guys who think they can spend $1200 and be on the road with a engine swap without a hitch. I'm not saying it can't be done, but "Murphy" is lurking behind every door!!! Cool

As for the flex fan, never a good idea!!! For normal use, a stock GM clutch fan is fine, upgrade to electric if you want but that is a option to consider later.

Exhaust "bolt ons" rarely exist in the real world, some tweaking usually has to be done. Timing tabs, why they don't just sell the cover with the tab as a "kit" is beyond me, but, that's the way of the aftermarket, when the sell them separate they make more money.

Your elky looks great, have fun putting some "shakedown" miles on it, ENJOY!!! Cool

_________________
Ol Paint and me

454/700R4/3.31 posi
8.30 @ 82.23 / 60ft @ 1.82
AND
14.5 mpg average on HRPT 2006

Pyromanaron · Posted: Thu Sep 06, 2007 10:27 pm Post subject:

Holy Crap! You sniped a van with your pulley?
_________________
Peace through superior firepower

L K meano biker · Posted: Fri Sep 07, 2007 11:34 am Post subject:

yup, right through the windshield landed on the pass seat