355 Blower eng. break in time n oil type q

[ABad84C-10]

Hello to all. I have just finished my 355 blower motor build. it has a 671 on it , hyd roller cam. comp is around 7:1 right now its underdriven until i get it broke in good which is partly my question to you guys. I am breaking it in on a conventional VR1 20W- 50. and plan to switch to synthetic. have only put about 50 miles on the truck so far tuning, tuning, tuning and bein careful making sure everything is good before i start runnin it hard. How many miles or hours should i run before the motor is broke in enough to switch to synthetic and what weight do yall recomend i run. this truck will be driven on the street every now n then but mainly building for the track.

[71Sixer]

Check out Brad Penn oil...really good stuff. It was recommended by a local machine shop for my dad's 496 race motor. Hopefully someone else will chime in on proper break in as I am no expert, but I'd say 500 miles at varying engine speeds and you should be good.

[68 C-10 KID]

^ I second that. I use the Brad Penn break in 30w oil. If you can't find that I would look into the Joe Gibbs break in oil.
I haven't broke a motor in on the street in a long time. I have been doing the dyno thing. So much info gained by that.

[BigDan3131]

You did change out the oil right after you broke it in I hope? 7:1 and underdriven? Is it a dog to drive right now? I normally take it easy the first 1K miles or so. How big is your cam?

[ABad84C-10]

i changed the oil out after i ran it on the stand a few times. and im not positive on the cam size. all i know is thats its a hyd roller. i know they like zink. The truck drives pretty decent on the street idles good at red lights n what not. i have a mechanical dist right now n it started giving me problems right before i came offshore.....i will be putting a locked out dist...with msd.boost retard plus the vac adv all on the box..im still looking for advise to see if this will be the best setup for this engine combo...thanks for what you guys have given me so far!

[ABad84C-10]

68 c10 kid. i feel u on the dyno thing. my buddy has a chasis dyno and i can pull for free whenever i want. still trieng to get the infant motor to walk before it runs.....once i get all the bugs out i will be doin couple 6k pulls on it at first...

[68 C-10 KID]

Nice

I'm not sure about the how to set up a blower motor dist.
I do know that running a locked out dist on a NA motor on the street is not all that great. Bad street manners, hard starting unless you have a start retard.

[BigDan3131]

I ran a Mag locked out on my 327 and it was a pain.

[Marv D]

Don't forget your bearings in a high pressure application like a blower motor, are going to demand the anti wear properties of ZDDP just as much as a flat tappet cam. If you have a bundle invested in the rotating assembl I'd not risk it on any over the counter 'driver grade' oil.

But that's just my 2¢ We built my son a 383 for his camino and it has seen noting but meticulous maintenance every 2500 miles and a bottle of EOS every oil change,, He used the EOS and ZR-1 because it was a bit cheeper than the 'real' offroad oil. Cam lobe went away last week

Now he's going top pay and pay dearly for that decision. Car is parked until we can pull the motor, disassemble and clean everything, then all new bearings freshen the hone, rings.... and a roller, and nothing but REAL oil from here on. Destroying a $4k motor over a $80 cost of an oil change ,,,,,, (hangs head, I thought I taught him better)

[ABad84C-10]

Yeah i've heard nothing but good things about VR-1 so far. it also has ZDDP. So for now thats what im gonna continue running. I got the guys at the local speed shop even saying thats what they would stick with so guess i'll just have to wait n see. I just dont know about switchin to the synthetic. I've never used it and am sketchy about trusting it now especially on the money i have invested in this thing. synthetic in an old school 350 just dnt even sound right to me.

[ABad84C-10]

Also came home from work crunk the truck up. drove it a few miles....Put my foot in it and Pow!! Backfired through the waist gate!! Yup you guessed it....Broken valve spring...numb 2 int. SO... now 1st off should have started with new 1's of the dump but they looked fine so i didnt. this motor was previously built got bored n rebuilt, i bought it before it even was crunk up. All new rotating assembly, crank, rods, pistons, cam, bored block...only thing used were the supercharger and the heads n valve springs.....which are H-Beam rods, dish pistons(forged). steel crank, n get this SBC TRICKFLOW TWISTED WEDGE HEADs (aluminium.) They were made in 84 i believe. i like them... cant find stud girdles though. I dnt even think they make the twisted wedge for sbc anymore. got this whole set up for less than 5k. broke everything dwn and built back up checkin clearences n got the heads redone. was kind of nervous cuz it was halfway built but never fired up. First time we crunk her she GOT EVERYONE'S FULL ATTENTION!

[ABad84C-10]

Also lookin for some new valvesprings now. gonna go with the best money can buy. dnt know the exact cam size but i know its hyd roller w lift @ 1.5:1 .575"/.575"

[blackedoutharley]

Blower motor with a waste gate?

My b.s. meter is pinging.

[Marv D]

Yeah I think 'wastgate' was an improper term,, blowers have a similar spring loaded contraption at teh base of the blower to relieve pressure,, can't remember what they call it in the street application, in the big dawgs it was called the burst panel.

Abad84,, I don't know much about blower motors, but this i do know BLOWN MORTORS LOVE INITIAL ADVANCE. Get someone who knows the ignition demands of the blown gas motor to set up your distributor before you do more damage. A typical blown gas street combo will like 15-20+ INITIAL, and have a short mechanical advance of 10-12°

You probably also bent a pushrod and or fractred a rocker in that little backfire. Check everythign THOUROUGHLY before you just assume it's onlya broken valve spring.

The carbs for a blower motor are a little different tune also. You want something to nearly DROWN the motor with accelerator pumps, and run PIG PFHAT ,, then tune down from there. Starting on the other end of the spectrum is asking for bent rods, broken parts and .....well,,,, Here's a scenario a buddy went through with a 671 blown 454 with a pair of CarbShop 750's supposedly set up for a blower.
First he was amazed at the headers woudl GLOW in the dark at idle. (cause:, too little advance and the fuel was burning in the header tube,, trying it's best to take the exhaust vale out)
Every time he stuck his foot in it , it would backfire and pop out the spring loaded burst panel. (cause:, stock street type squirters in this "blower carb" with stupid 30cc accelerator pumps)

Can was a hydraulic flat tappet Comp Cam 'street' cam with the springs the cam called for (STUPID MOVE with 6-8psi of boost!!!, boost comes up and the door couldn't close fast enough with the soft springs)

Results,, after 2-3 months of tinkering and trying to blow the thing up,, he succedded. He stuffed his foot in it, it poped, broke a chunk of the cam out and it fell into the rotating assembly. Total engine destruction.

GET SOMEONE THAT IS EXPERT IN TUNING A BLOWER MOTOR before you follow his footsteps.

just my 2¢, wish you luck

[GMR-PERFORMANCE]

Harleys are almost all roller bearings, however there are other issue with them. We run Torco oil. They have a break in oil that is more for cars called TBO ( torco break in oil) I break all of the engines in on it. As for SYN I would wait at least 1000 miles to swap over. Cost is one reason. I would have at least 3 oil changes on that engine by 1000. I want to see what is going on. Looking for any signs of issues. Run a quality oil with the right "package in it" change it often.

The Torco oils have the additives that you need TBO or other wise.

I run the SR5 in my LS engine marv out in the dunes. One oil change per season. Never a issue.

Many big names want torco oil inthere items. Lenco, Mercury Marine, Albines,

http://www.torcousa.com/products-auto-pro.html#top

Oil is a ford chevy deal, I have run many oils and I can say that I have seen several of the big name SYN oil create issues in the HD engines. And for what is worth, I have no idea how a ball bearing scar test proves anything when it comes to a engine