Engine and Transmission Tech

Hi all,
Can you fit flanged liners into a early 2 bolt 3.9 Rover? Was also thinking in order to stabilize main caps, has anyone doweled the main caps to the saddle?

Regards

Jason

Dowelling the main caps is something I wish I'd done on my 340 Buick. Once clamped securely they may not move much but there is a fair bit of leeway in the installed position fore and aft that needs to be accounted for in order to get proper bearing match, and with the tight clearances these bearings need to run it's even more important. It does however remove a couple of the threads from the block and in aluminum the cap bolts need all the help they can get. In the 215s thread strength is marginal and I don't see why the Rover blocks would be any different. So studs are the best thing you can do for them, and thread inserts might improve things further if properly done. Can't tell you how many times I've disassembled the main caps or heads and had bolts that were nowhere near full torque.

As for the flanged liners, I can't imagine why they wouldn't work but have no personal experience with them.

JB

Jason, IMHO pouring that kind of time.$'s into a 3.9L. block could be better spent on a 4.0/4.6L. They are both plentiful and a good value, "if" you dig. Good Luck, roverman.

Hi guys,
Just not sure which way would be best. 3.9 = no flanged liners needed, smaller main bearing journals (less bearing speed) but only 2 bolt. 4.6 = cross bolted mains but flanged liners would be a must but flanged liners also open up larger bore sizes as well.

Also I don't know if the early 3.9 front cover would fit either.

Jim, already have studs for the bottom end but have noticed that some small block Chevs were dowelled and some connecting rods are also dowelled. Just a thought.

Thanks for the replies guys.

Bearing speed has not proven to be a problem on the larger small block Buick engines so I wouldn't worry too much about that, but I would avoid replacing liners if I could, as that tends to be expensive. Be very particular about your bearing clearances though and keep those tight.

JB

Jason and clan, the 4.6L blocks were sonic tested for core shift, in the bores,( color coded pink). If you find one without 1+ dropped liners, and have it sonic tested,(around $80.), you possibly save the cost of flanged liners. Good Luck, roverman.

Does any know if there is a "Procedure" Rover used for thier in house "sonic" testing of the liners? I have all that equipment to do sonic testing and would love to see how well thier method works versus the indisutrial methods I use for bond testing.

Mike and clan, "Dugans" is a highly repected, hiperformance/racing, auto machine shop and they test (12) places in each bore, (4) at top, just below deck, (4) in middle and (4) at bottom of water jacket. (8) bores cost $80.- a good value. I've had rovers sonic tested with liners in place,(operator takes a test reading for "both" metals. How Rover tested?, I don't know. Good Luck, roverman.

I'm certainly not an expert in ultrasonic thickness testing.
But I don't think that you can reliably test steel lined cyl bores in aluminum with the equipment at your average machine shop.
The two different densities and the possibility of air gaps with a pressed in liner preclude anything accurate.
AFAIK you would need the liners out to measure the block, which at the end of the day doesn't really matter because you have liners with a known thickness.

Cheers
Fred



Edited 1 time(s). Last edit at 07/21/2011 08:31PM by DiDueColpi.

The issue I see with Ultrasonic Testing of these liners are two fold. The first is you need a sample that has bond and an area of non-bond (attenuation vs. reflection). That proves the method. The other is the casting behind the liner is not uniform so all it takes is assuming you may or may not have bond and also what is acceptbale and what is not? I do bond testing of Babbitted Bearings for Turbines and the issue I have is part geometry such as oil ports can be frustrating. I have a 3.9 block in my house I am going to UT where I know there is aluminum and where there is not behid the liner. I also have a video borescope I can use to go into the block and see what is inside. I have the tools.....45k video borescope and 25k UT scope and would love to get the liner issues worked out since I have access to about 20 4 bolt main blocks that are all mystery meat. Im sorry but a guy at a machine shop with a UT scope scares the heck out of me.

Good Bearing Bond..........

Bad Bearing Bond

Sooo, You got a "pink" block with no dropped liners, maybe a 1/2 fill of "Hardblock" etc. and run the snot out of it ?