MGBV8 Carl Floyd Kingsport, TN (4511 posts) Registered: 10/23/2007 11:32PM Main British Car: 1979 MGB Buick 215 |
Rover Cylinder Liner Issues
As we all know, The Buick/Olds 215 did not suffer from liners moving because they were cast in place. Rover didn't do it that way. Maybe they couldn't or needed a more economical solution. The Rover 3.5 seemed to be fine, but once the block was opened up for the 3.7" bore they started having issues.
From the V8 Owners Forum: I have posted this up before, and I am sure I will be shot down again. :) 3.5 very rarely drops liners 3.9 also relatively rarely drops liners 4.0 2nd grade big journal blocks, drop liners quite often 4.6 top grade big journal blocks, drop liners the most I believe the small journal crank causes less flex in the block around the base of the liner as it is less stiff so causes fewer cracks in the block in this region, further the bigger journal weakens this area of the block further relative to the stiffer skirt of the engine on these blocks (resulting from the cross bolting tying the bottom of the engine much better) Part of the reason I think this is that the TVR 4.5 and 5 litre engines are small journal non cross bolted and seem to suffer less from this issue. Yes a lot of advice is based on what the party concerned has to sell and if you read what is commonly written you would believe the RV8 was ready to drop a liner at any moment, they are not as bad as they are portrayed. Top hat liners work but remember it is effectively converting the engine to wet liner which to me is not the answer to a problem of badly designed load paths. Redesigned aftermarket blocks are nice but if you have the money for one of those spend it on a Chevy LS* engine and have something modern that will produce real power for heaps less money |
Re: Rover Cylinder Liner Issues
I had the dreaded cylinder tick in my 4.2L for 10 years and 2 summers ago I finally lost my patience with it.
Last winter I pulled my 4.2L engine, put it on a stand and pinned the cylinder liners to the block. I didn't remove the crank or pistons, was just careful not to get metal shavings up in anything. I also used a lot of brake cleaner to clean stuff out before I put the oil pan back on. I drilled holes in the block beneath the water jacket and threaded them with a 1/4-28 threads. I used 1/4-28 set screws and ground the end flat on my belt sander. I then put a nut on the outside and tightened it up against the block with the red locktite. I put 2 set screws in each cylinder (16 total) as a way of making sure I didn't miss anything. On startup I had a pretty nasty vibration, which means I had a set screw barely sticking into one of the cylinders. After 50 miles or so the vibration went away. I guess the piston and set screw learned to live together. :) This was not a hard job (in the sense of coal mining, putting men on the moon, or replacing a 4cyl mgb clutch with trans still in car) but it took time to do properly. Maybe I invested $50 into the whole thing? I probably only did 1000-1500 miles this year, but so far so good. I generally followed this guide: [www.landroverresource.com] |
MGBV8 Carl Floyd Kingsport, TN (4511 posts) Registered: 10/23/2007 11:32PM Main British Car: 1979 MGB Buick 215 |
Re: Rover Cylinder Liner Issues
I have seen that, Justin, & considered it for my 3.9. Sometimes they develop cracks behind the liners, as well.
Another 4.2 owner with liner issues. Glenn Towery & Woody Cooper have also found the 4.2 to be prone to slipped liners. |
MGBV8 Carl Floyd Kingsport, TN (4511 posts) Registered: 10/23/2007 11:32PM Main British Car: 1979 MGB Buick 215 |
Re: Rover Cylinder Liner Issues
Repost from a previous thread.
More on Rover blocks: Quote: Edited 1 time(s). Last edit at 12/12/2016 12:00PM by MGBV8. |
BlownMGB-V8 Jim Blackwood 9406 Gunpowder Rd., Florence, KY 41042 (6468 posts) Registered: 10/23/2007 12:59PM Main British Car: 1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS |
Re: Rover Cylinder Liner Issues
I have also heard that the 3.5 Rovers may have issues with cracks at the main bearing bolt bosses. I do not know if this has been reported from more than one source however. (In Australia)
There are plenty of Rover engines out there running without a problem. But it does seem a bit like Russian Roulette. Tends to give one pause when considering putting money into a Rover build. I never had the problem because I stuck to 215 blocks, but they had thread pull issues which really wasn't any better. No roulette though, they all were the same. There is a big difference in a dry liner and a wet liner and that is wall thickness. Wet liners are almost always at least 3/16" thick and often more. Plus the head studs go to the bottom of the water jacket. A top hat liner does rely on sealing more than a straight dry liner but it also seals better at the top. It is however horrendously expensive, money that could otherwise go to CNC ported TA heads. But it seems to be the only way to be sure, short of an iron block. If only Rover had ever taken the time to properly cure the problem. Jim |
mgb260 Jim Nichols Sequim,WA (2461 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Re: Rover Cylinder Liner Issues
Common cylinder repair sleeves never have problems. They have a step on the bottom of the block and are flat on top where the fire ring is. There is also Locktite sleeve sealant. If I was home at my shop I would be tempted to get a block with loose sleeves to experiment with. Is the bottom of the sleeve flat? I would use a flex hone to clean and rough up the bores and a wire brush on the sleeves. Cool the sleeves, reverse them, coat the bore and top 3" of sleeve with Locktite sealant and press them in flush. Wipe off sealant on top and bottom of bore. Use a old head gasket and torque the head down. Then I would pin them so they can't move as in the thread above. Bore out to standard Chevy 305 size of 3.736. .036 over Rover 3.7.
Edited 2 time(s). Last edit at 12/12/2016 12:55PM by mgb260. |
Re: Rover Cylinder Liner Issues
So, here's a dumb question; it sounds like the original liners were not installed all the way to the bottoms of the cylinders. If longer liners were installed so that the bottom of the liner was snug into the step in the bottom of the cylinder, and the top of the liner was cut to be flush with the deck surface, would that work?
I like Jim's belt and suspenders approach to fixing the problem. Jim, what did you mean by 'reverse them'? Install them upside-down? When I had an Olds 215 block rebuilt, the tops of the liners seemed to be sitting slightly proud of the deck. The machinist had to buy a special bit for his Rottler F-65 to cut the deck flat. The combination of cutting aluminum and iron was the issue. |
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mgb260 Jim Nichols Sequim,WA (2461 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Re: Rover Cylinder Liner Issues
Paul, There is no real step, a partial piece of casing flash here and there. I would rather have a flat on top to seal on the head gasket fire ring instead of existing bevel edge. I've never had one out to look at, and am hoping the bottom is flat. The bolts on the bottom and adhesive will stop any movement.
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roverman Art Gertz Winchester, CA. (3188 posts) Registered: 04/24/2009 11:02AM Main British Car: 74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L |
Re: Rover Cylinder Liner Issues
"IF" a slipper skirt piston is used, perhaps with the shortest possible 90 deg. drill attachment, one could drill a transverse hole near the bottom of two companion liners,(if solid aluminum between them) ? IE, the bolt would be safely below the ring package of the piston. This should provide substantial lock, for both liners. art.
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Re: Rover Cylinder Liner Issues
The 3.5 blocks have a cast shelf at the bottom of the bore. The problem is the liner doesn't reach the shelf. Replacement liners bottom out and then get milled flat at the top of the block. The later 4.0 4.6 blocks don't have the lip. They were bored all the way down and then the liners were pressed in.
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mgb260 Jim Nichols Sequim,WA (2461 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Re: Rover Cylinder Liner Issues
Todd, Could you look at your 4.0 block and tell me if the liner is flat on the bottom and not beveled like on top.
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harv8 Martyn Harvey Waterloo, Ontario, Canada (189 posts) Registered: 10/23/2007 10:09PM Main British Car: MGB Rover V8, TVR Chevy V8, MGB GT Ford V8 |
Re: Rover Cylinder Liner Issues
I am about to assemble another Rover V8 motor for my next MGB GTV8 project car. I want a mildly tuned/reliable engine and I have three to choose from my collection. I don't want to spend much money! So which would you guys choose?
1 - Early 90s 3.9 block, SD1 heads 2 - SD1 3.5 block, Vittesse 9.75:1 pistons, SD1 heads 3 - Early Rover 3.5 (1970) block, 10.5:1 pistons, early heads or SD1 heads As you know, I have been driving my 3.5 SD1 based engine successfully since 1996 without issues. I am concerned about the liner slipping issue with the 3.9. I have a lovely low mileage stock 1970 engine that i have been saving for so many years and think it deserves to be re-assembled and used. Thanks for any input, i value your knowledge and expertise. Martyn |
MGBV8 Carl Floyd Kingsport, TN (4511 posts) Registered: 10/23/2007 11:32PM Main British Car: 1979 MGB Buick 215 |
Re: Rover Cylinder Liner Issues
If you want a bit more power use the 3.9 with pinned liners. If you are okay with the 3.5, that SD1 is a superior engine to the 1970 engine.
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Re: Rover Cylinder Liner Issues
They are flat on the bottom. Had to look real close and I saw something I never noticed before. It looks as thou when they bored the cylinders, they did it in two passes. Just below the bottom of the liner, the bore steps just a hair. Looks like they bored it all the way down with one size cutter and then went back with a cutter that was just a few thousandths larger and bored it a second time,but didn't go as deep. Left a tiny ridge just below the bottom of the sleeve. Obvious that they could have just bored it, left a shelf, and kept the liners a hair long sticking out of the block, then machined them flat. I'm guessing the first bore took away a bunch of material and the second bore was more precise to make sure everything was nice and straight. That first pass really goes deep into the block below the sleeves. It even removes material along the skirt of the block walls a good inch deeper than you need.
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Re: Rover Cylinder Liner Issues
I've done some web searches for the fixes for slipped liners but still have a question;
If the engine is leaking water in a cylinder, can that be repaired? I have a recollection of Jim B. saying it can be welded (and re-bored, of course) but then the block might need to be heat-treated to restore its temper. |
mgb260 Jim Nichols Sequim,WA (2461 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Re: Rover Cylinder Liner Issues
Todd, That confirms my idea of turning them around. Thanks! Art's idea of bolting pairs internally is definitely thinking out side the box. Paul, I'd use aluminum brazing rod to repair small crack. No heat treat, you use heat on the block to remove and install the liners. The guy on You Tube used a Propane brush burner.
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BlownMGB-V8 Jim Blackwood 9406 Gunpowder Rd., Florence, KY 41042 (6468 posts) Registered: 10/23/2007 12:59PM Main British Car: 1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS |
Re: Rover Cylinder Liner Issues
I don't recall a discussion of welding cracks behind the liners, but I think it would be a wasted effort. If the wall is thin enough to crack, it is probably going to melt away as soon as you strike an arc on it, and getting a TIG torch inside the cylinder would make for a difficult job and create warpage. Better to seal it at the top and bottom and hope for the best I think. None of these band-aids are going to make for a reliable engine, but could eke some more life out of one in some cases. I consider it pretty poor engineering to install dry sleeves and not limit their movement in a positive way at both ends though. Press fits (shrink) have their place of course but on something with constant high speed reversals you really should have positive stops. Jim N's idea of inserting the sleeves upside down appeals to me provided the flat part of the end beyond the bevel sits against the shoulder of the bore and the sleeve is at least flush with the deck after being fully seated. I would concentrate my efforts on the lower seal and rely on the head gasket to seal the top.
The use of locktite has some merit, depending on the temperature of the block when the sleeve is installed. You wouldn't want to burn it. The weed burner is a step in the right direction but providing some walls and a lid to make a rough oven would give more even heat. That could be fire brick, dry dirt, metal, even possibly wood under the right conditions. It's not like you are firing ceramics. Chilling the sleeve in dry ice will give you a little more leeway in terms of time to get the liner in, and clearance to get it inserted. But make no mistake here, this isn't going to be a situation where you can just throw the liners at the block and then go have a beer. You'd better have some mechanism handy to press the liners in once you can't shove them by hand, because once the liner warms to the temp of the block it isn't going to want to move any more. And you wouldn't want it to. Otherwise it'd be rattling around when you drive. Oh, wait. That seems to be the problem, isn't it. Well, the difference between that and proper operation is something on the order of 0.0002" of interference, maybe slightly more. Personally I absolutely hate trying to bore holes to that close of a tolerance, and doing it in production? Well there will be some variances, I'm just saying. So overall, much better to just find a block where the liners haven't moved. Jim |
roverman Art Gertz Winchester, CA. (3188 posts) Registered: 04/24/2009 11:02AM Main British Car: 74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L |
Re: Rover Cylinder Liner Issues
Jim B and clan, I suggest , .002" is about the desired interference. Much more will have a tendency to crack, the aluminum bore, after it cools. Years ago, I ran tensile strength test on a 215 block,(semi permanent mold) and rover,(sand cast). A.I.R., 215 tensiled 15-20% higher, likely due to density. I like the idea of "sealing" the coolant passages of the block, after sleeving, using sodium silicate. This is what worked for Smokey Yunick, tying to use iron sbc heads, at Indy. Jim N., what is your trick for removing rover sleeves, un-harmed ? Cheers, art.
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mgb260 Jim Nichols Sequim,WA (2461 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Re: Rover Cylinder Liner Issues
Art, Here you go! Brass drift to get started until you can grab it with welding gloves. Two man job, one cylinder at a time.
[www.landroversonly.com] |