So... Guzzi Mark's chop top Valiant engine sure ran good at Redding... until it locked-up solid... ""tighter then a frog's butt" is how Mark described it.

So, as the poll suggests, is there a particular rod bearing that seems to fail more often then the others?
If so, why?
Any tips for keeping a SL6 bottom-end "alive & well"?

madmax/6 (Mark) will have to tell use which rod spun, once he pops the pan off the engine.
DD

I vote for #1, the furthest bearing from the pump if the gear died. If the passages are full of shrapnel, then it could be any one of them!

Too bad he wasn't running synthetic oil. After my oil filter collapsed I drove it another 20 miles with zero oil pressure to the nearest auto parts to by another filter. Then I drove it another 60 miles home. By using synthetic oil I only had to grind the crank .010 under to get the scratches out.
Now that is tough!

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

I'll say #5 spun.... That car is one hell of a ride! Wish you luck on getting it squared away.

TF

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Even in moderation i am excessive!

vote #5, as that is what I have heard about most times...
Bad bearing, then the rod knocks the starter off...

Well, this is just because I had to write/vote for something...I have no idea

we can only guess. i bought my car with a spun #2 rod bearing so that's my vote. sorry to hear the news, from what i hear you were spearheading that project and did everything right. i hope the engine provides some valuable information in return.

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

I vote number 5, as that is the only one I have seen wiped out. But with Doc doing the oiling mods, I don't think it is the "common" problem. Could be any one.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

When I first started racing slants, I had problems with #5. I don't/didn't do as many oiling mods as Doc. All I did was open the passages to the main saddles, the passages in the crank, and run full groove mains. I have broken many pistons, rings, and head gaskets, but no more problems with bearings.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

#5 is my vote to , i think it has more to do with the distribution in the intake that makes it lean out and load the bearing.

Why are we assuming it was a rod bearing? There are many possibilities of what would cause an engine to lock tight, isn't there???

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Chris'
Autobody
Restoration
Service

The description we got of the sound points toward a rod.

One just never knows though!

I heard it when Mark tried to turn it over again. It turned a bit, but very slowly. Sounded like a bearing spun and clamped down on the crank.

Mark, who has lot's of engine building experience, suggested it had the classic sound of a rod.

The only rod I've ever lost is #1, but for very different reasons. I vote... #5!

CJ

I vote for #5 as well as this is the one I have had on 2 slants spin. However Cars does bring up a good point do we know it is a rod bearing that spun???
Frank

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Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered

However, according the Larry Sheppard (Chrysler engineer, and editor of the "racing " manuals), "this is not an inherant problem of these engines". Yeah, right.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

SILVER poop everywwhere in the filter,I cut it apart,won't go further on the Guzzi car for a week or so, just got bottom end buttioned up on a bare block for my A100 tow truck today,want one together before i splatter another,while i have Guzzi motor apart, i will do additional,minor upgrades,think mid,low 13s are possible with my current combo, with good bearing! Mark

Upon review... looks like this engine was not getting enough oil pressure, only 40 to 45 psi.

My bad on that one, I usually set SL6 oil pumps to get 50 to 55 psi on "street performance" engine builds... This pump's setting came-up a little short on pressure and combine that with the last minute cam change... 40 psi of hot oil pressure is not going to "cut it" for a 6,000+ RPM SL6 engine.

After it's first pass at Redding, I should have climbed under the car and shimed the pump's releif valve.
DD

He shouldn't have been turning over 5500 with that cam and setup anyway. Seems like 40 psi should have been enough...

Glad to hear he turned 13s, though.

Lou

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