So, the cracked Rover blocks have been a problem for a long time now. And the ultimate repair solution has been a tophat liner repair.
This conversion works very well and fixes the problem for good. However, it also has a rather devastating effect on finances.
I've never thought that the actual crack was the problem. The cylinder liner should seal properly to the head through the head gasket. Even if coolant made it's way through a cracked block in behind the liner, it shouldn't be able to intrude into the combustion chamber.
What's happening is that the liners are badly machined. They have a very large taper at the top to allow easy piston installation. This taper is more often than not off center and removes completely any chance of a good seal to the head gasket.
The other issue is that the liner registers at the bottom of the cylinder bore. What this means is that as the engine warms up and expands. The aluminum block expands more than the iron cylinder liners. This causes them to lose contact with the head gasket and failure is just a stab of the gas pedal away.
Thinking that I was on to something I "O ringed" a failed block. I made a tool to score a groove around the cylinder liners just as they transitioned into the aluminum block deck. A 0.030'' copper ring was inserted into the groove and the heads were put back on.
That engine has worked perfectly for almost three years now. The only caveat was a very small coolant leak into the sump. I did something that I never do and put some block sealant into the engine. It's been perfect ever since.
After that success I realized that a little more work was needed on a long term fix. So with the next engine we pulled it apart and yanked out all the liners.
The deck was milled 0.010" the liners were flipped upside down an re-inserted with locktite sealant and the deck was then again machined 0.005". This left the liners sticking proud of the block deck by 0.005".
The reason to flip the liners is that the bottom is flat. No taper has been machined in. You now have a nice 0.050" wide sealing surface. I still don't like the bottom register, but the taper is not an issue here.
I have four engines running this way for over two years now and no signs of failure!
OK, so on to the Unicorn part.
As I said the tophat liner is the ultimate repair. Problem is I have too much Scotch, I mean Scot in me to pony up for them.
I have found a cheap tophat liner. It's from the chevy modular 4/5/6 engines. It's a melling part # CSL 356F and I just ordered 8 from Summit for $22.40 each.
They are 1.5mm bigger in OD than the range rover and come with an unfinished bore intended for 95.5mm. That means that they should accept the chev 305 piston nicely. Or use the modular piston with a slightly longer rod. The liners are also 10mm longer so they can be trimmed to fit. The best part is the tophat configuration. No more bottom register headaches.
Simply bore the sleeve to fit, provide the appropriate notch at the top of the bore to accept the tophat step and away you go!
With the liner now retained at the top of the bore, the block can do whatever dance move it likes. The head gasket don't care.
I'm thinking that an oring at the bottom of the bore would be a wise move. I will decide whether to machine it into the block or liner once the parts get here.
Live like you mean it.
Fred
Nicely done Fred.
Jim
QuoteI have found a cheap tophat liner. It's from the chevy modular 4/5/6 engines. It's a melling part # CSL 356F and I just ordered 8 from Summit for $22.40 each.
They are 1.5mm bigger in OD than the range rover and come with an unfinished bore intended for 95.5mm. That means that they should accept the chev 305 piston nicely. Or use the modular piston with a slightly longer rod. The liners are also 10mm longer so they can be trimmed to fit. The best part is the tophat configuration. No more bottom register headaches.
Thanks for that info, Fred!
Fred, I mentioned flipping the liners a few years back. I know I had Todd check out a 4.6 block he had in his collection to verify they were flat on the bottom. Never made sense to have a taper at the fire ring. What interference fit for the top hat liners will you use? What type or number of Loctite? The top hat liners sound like a perfect alternative.
Fred,
Will the machining not easily surpass the cost difference between the liners? Looks like under $500 CDN between the Turner Engg ones and Summit, plus you could use your old pistons rather than buying Chevy ones if in good shape.
Hope my 4.6 L never starts to have issues so I can be left in the dark on this topic!
Mike, The Turner top hats will require machining too. The liners Fred found save you $500. Chevy Hyper 305 pistons are fairly inexpensive and allow you to build what you want for rod length and compression. There are different compression heights for 5.7 or 6" Chevy rods and dished for stock heads and flat tops for 300 Buick heads. I like his idea of flipping the liners. I'd use 4.0 pistons in the 4.6 and put larger valves in the stock heads.
We will be needing pictures to make this great thread even better !
FWIW., Loctite 620, "retaining compound", it's green and hi-temp. DO NOT get crazy with interference fit ! I would not go over .002", at room temp. Remember the thermal expansion of alum. vs. steel ? Get your re-sleeved block too cold and the aluminum can crack, from being over-tensiled. Wildcat,(Wales), used to sell flanged liners. They were priced right, so I bought 3 sets. Never could trace who "made" them.
Onward, art.
Fred, Since your now silently elected as "Rover V8 liner GURU", perhaps you could share your labor techniques ? Things like best method to heat the block, including temp ? Hyd. press/out, of the sleeves? Many Rover block "lives", are at stake....
The Turner ones are made by Darton but, Darton won't sell them to you. They must have an agreement. Art, thanks for the info. I know aluminum expands about twice as much as steel when hot. At 180 to 200 degrees it is pretty close. Have you checked out the thread on Mgexperience on heat treating the 300 Buick heads?
I've used loctite 640 for all of the liner installations.
It's thinner than the 620 and cures slower giving you a little bit more time to get everything back in place.
For the flipped liners I just clean everything up with "Scotch Brite" pads ( because they just seemed proper)
Pop the block into my kiln @250'f ( the kiln is made out of fire bricks and an old oven. it's mostly used for powder coating. I can re-stack the bricks any way that I like for a particular part. works great.) and throw the liners into the coffee room freezer for a couple of hours.
Once everything is ready, I brush the loctite onto the block and just slide the liners in by hand. A couple of taps with a leather mallet seats them all the way.
Don't put loctite onto the chilled liners, it becomes unstable when it freezes.
As far as pulling the rover liners I use a home made puller. Its a simple bridge puller made from 1" thick wall steel square tubing.
I machined a plug that locates in the bottom of the sleeve. A piece of 5/8" ready rod connects the two together.
Mount the plug into the bottom of the sleeve, place the bridge onto the block deck, insert the ready rod and a couple of nuts and crank away. The liners come out easily on a cold block.
For the tophat liners I think I'm going to fit them fairly tight. The first engine that I'm going to try this on is the Lo-ver engine. I want some solid contact to the block for cooling and for locating the bolted on deck for the lotus heads.
0.0035" to 0.0040" interference fit is what I'm looking for.
Here's a few shots of the Rover and Chevy liners that I just pulled from some old blocks.
IMGP0028.JPG
You can see how thin the sealing edge of the Rover liner gets.
IMGP0031.JPG
And how much bigger the chevy is.IMGP0033.JPG
the rover becomes virtually razor sharp in places
IMGP0030.JPG
Live like you mean it.
Fred
I have no dog in this fight at all but this is a VERY interesting thread! Nice work Fred!
Find any cracked blocks, Fred?
I have read & seen pic where the block cracks behind the liner near the head bolt hole. Seem there is not enough aluminum in htat area because of the increased 94mm bore.
https://www.youtube.com/watch?v=zlRkbeY7_IY
Yep, all the time Carl.
I'm still not convinced that the bigger bore is the culprit though.
The cracks are usually in cyls two and five. The head bolt bosses in those cyls, as in most of the others, aren't connected to the cylinder bores until you get to the underside of the deck. The cracking occurs much further down. And never on the outside of the block where the bosses are connected.
To me it's a combination of a more brittle block. The later blocks appear to be much harder than the earlier ones. Torque to yield bolts. and possibly harmonics transferred up from the stiffer cross bolted bottom end.
To get around this I generally bore the head bolt holes down much further. You will break through on most and will need to use sealer on the threads. I then use head bolts from the Volvo " white block" or 850 engine. These bolts are far too long and need to be cut to fit. But that's an easy task. They are also 12mm thread so the block needs to be retapped for that.
Now you have far superior thread engagement much further down into the block.
On the Lo-ver engine I've gone all the way and bored the head bolt holes all the way down to the bottom of the cylinder bores.
This requires some inventive sealing and custom studs. But relieves the upper deck and cylinder bores from any untoward stress.
Here are the Rover and Volvo head bolts side by side.
IMGP0043.JPG
And here is the home made sleeve puller.
IMGP0045.JPG
Cheers
Fred
Fred, Thanks so much for this sharing. I hope the new press fit works out. Last pic, is that an "early" RV8, that the puller is resting ? Have you used studs, on any re-sleeved RV8's ? art.
Thanks Art,
Could be, it has the same cracking problems! ( it's actually a Merc flathead v8 / showroom coffee table.)
I don't use studs unless the engine is coming apart regularly. Too much hassle for no real return in clamping.
Cheers
Fred
So Fred, on the Lo-ver you're tapping the studs into the main web? You've got me really curious about that. Would you care to share more of the details?
Jim
Yep, made sense to me to move as much of the clamping load down the block as I could. It eliminates any side load distortion from the cylinder bores. And it takes the load down closer to the crank where it is more useful. Also if you remember | milled the deck off and replaced it with an aluminum plate. This helps to sandwich everyone together.
Several, actually quite a few of the studs exit and re-enter the confines of the block. I've made provisions for Orings but whether that works remains to be seen. I really should dig the motor out from storage and post some pics. That would explain a lot.
Cheers
Fred
My new liners arrived today!
The unfinished bore measures out @ 094.625mm which opens the door to a few more piston choices.
I'm going to strip down a 4.6 and send it off to get machined for them and see how it works out.
IMGP0075.JPG
Yep, I chickened out on doing the Lo-ver first.
Too much time and effort into it to experiment that hard on it.
Perfect for the 305 pistons!
Got 4.6 block stripped down and pulled all the liners.
It's off to the machine shop on monday.
Going to use 5.3 ls pistons and rods. That gives me a nice modern piston and 6+ inch rod combo at a reasonable cost.
It also lets me destroke the crank slightly to 03.096" to get a 0 deck.
That stroke with the 96mm bore still works out to a 4.555 L engine.
You could also use the 4.0 crank with this combo and deck the block very slightly to get the same result.
Fingers and toes crossed.
Cheers
Fred
Fred, Wow! 3.78 bore! How thick is the remaining liner? Do you have to mill the rods big end on one side like the SBC rods to get the right offset? What is the compression height of the piston and rod length?
The liners are 3.920" od. so I'm pushing the limit a little I think.
The 4.6 liners measure out at 0.072" so based upon that I should be ok.
Yep the big end needs to be milled. Will do 0.050" per side so that the Chevy bearing will still fit.
Compression height is 1.3140" and rod length is 6.0980".
The difference between the Rover rod journal and the Chevy is 0.0850" so I have 0.170" stroke variance to play with.
You could even get away with the Rover 4.6 rod as the pin is the same @24mm.and the length is close @ 6.110" but it would mean milling the piston and until I have one in hand I don't know how feasible that is.
I know that the compression ratio is a little whack but the heads are the 300 ones so not too much work to cc them. The pistons have an 8cc dish and should be up to at least a little massage as well.
Thanks, Fred!
Sounds like a pretty good combination.
Jim
You're killin' me, Fred!
"The liners are 3.920" od. so I'm pushing the limit a little I think."
Considering there is really not enough meat in the block with the stock liners, I would think the same.
That's possible. Sometimes we go too far with these engines. That reminds me of a certain ill fated wet liner project awhile back. But, if we don't try we'd never know would we?
Do you suppose there is any reason why we couldn't use a higher quality metal in the liners, such as for instance a chrome-moly steel?
Jim
The red block that I'm using should leave me with at least a 0.100" min. cylinder wall thickness. And yes it will be checked.
That along with the 0.070" liner wall thickness should be more than adequate for the power level that I'm looking at.
If I were using power adders or winding it up hard, this would be a different build. But I think that this will be a comfortable 250hp 6500 rpm engine that should stay together for a good while.
So I'm really hoping that you're wrong Carl. :-)
I am open to constructive criticism and inspired opposition. But I'm also a stubborn old shit, so I've got to give it a go!
Live like you mean it.
Fred
Got my fingers crossed for ya, Fred!
I have used the calculators for hours & hours juggling the 3 different Rover strokes with different rods & off the shelf pistons attempting an easy bolt together engine. I have finally decided custom pistons is the easiest route. And, maybe not any more expensive if it offsets some machine shop work. Seems there really is no such thing as cheap when building a Rover V8.
Yah, I know Carl. My brain is still a little fuzzed out from that exercise.
It may still get custom pistons as the measurements on the world wide interweb are all over the map.
Won't know for sure until I have the parts in hand. Hopefully by the weekend.
The good news is that the block has been tested and there is nothing below 3.0mm for bore thickness.
The bad is that they have to make a counterbore tool for the top of the cylinder. And that might take some time.
Oh well, no rush. I don't even know what I'll put it into yet.
Cheers
Fred
3mm is 1/8", should be OK with the liner. Can't wait to see how it turns out.
Jim
Found another piston option if the LS ones don't pan out.
It's right back to the good old 305 chevy
Wiseco has an off the shelf piston that will work with the 4.0 rover rod and 4.6 crank.
Part # K0137X3 is a forged piston 3.766" bore, 0.927" pin with the near perfect 1.250" compression height.
A little spendy @ around $650.00 per set but probably cheaper than all the machine work that I'm staring at.
And it buys me another 0.034" of liner thickness.
Just have to bush the rover rod.
Still going to try the LS stuff first as it's paid for and shipped. But we'll see.
I have been watching this thread to see how things turn out. I still have a 4.0 engine. I was researching the use of Sodium Silicate as a block sealing solution, possibly even a block repair solution; mixing aluminum shavings with Sodium Silicate and applying it in eroded or cracked spots.
I would want to use Fred's 305 liners to make a 4.9 (or bigger) stroker motor.
The LS pistons, rings and rods arrived today.
Didn't have time to measure anything. But will check it out and post pics tomorrow,
Here's hoping!
Fred,
You might want to double-check the LS rod offset, in the RV8 bore ? SBC needs different side/side to center in RV8. Too bad you don't like hyd. roller cams..... Good Luck,( probably won't need it).
Ok, so pulled out the old measuring stick.
The rods are exactly as expected with an average 6.0988" center to center.
The pistons look good with a 1.318" compression height. All eight are exactly the same which is impressive for the white box units that I purchased.
IMGP7331.JPG
The pistons are cast and look decent. With a projected 32hp per hole and 6500 rpm ceiling they should be more than adequate.
IMGP7332.JPG
They also have a 70 thou dish. Which means that I can reasonably shave 80 thou off the piston and use the 4.0 rod with no mods!
IMGP7333.JPG
If I can gain enough chamber in the 300 heads this might just work.
Cheers
Fred
"The pistons are cast and look decent"
Yes they do. Not plain ol' cast pistons. Hypereutectic, right?
Yes you're right Carl they are HT.
Patiently (sort of!) waiting for the liners to get fit into the block.
Cheers
Fred
FWIW, Smokey Yunick, never would have made sbc's live at Indy, without sodium silicate(egg keep/old school).
Fred...updates
Just a bump to see what Fred is up to!
Fred, Anything new?
Fred
Any updates
Please check in
What happened to this project, Fred?!
Maybe a lil' block filler ?
Fred, Any thing new on the build? Hope everything is OK with you.
Can anyone check on Fred? His last activity here was on May 29th.
Fred, You OK?
I think that Fred was from the lower mainland of British Columbia.........the Vancouver area. Always followed his posts. Going to the worst case scenario, here's an obituary for a Mervin Frederick Key, passed away on August 24th, no detail in the obit. Hope I'm wrong.
https://www.dignitymemorial.com/en-ca/obituaries/vancouver-bc/mervin-key-8846845
Phil, Wrong Fred. Fred last posted here 8/28/2019. Still odd he hasn't updated us on his progress on this project.
Did he actually post something 8/28/2019, Jim? I see that is his last activity date, but could just be the last time his account visited this site. Something is not right.
Carl, Remember on the Chump Car project he had a truck driver (Todd McCreary) on this board stop by and get a T5. I wonder if he has a route in that area and can check on him?
Are you able to check on Fred, Todd?
I have some info on FRed .Just testing to see if I can send a post
We look forward to an update on Fred. Hope the news is not despairing.
I'm not good with computers and yesterday I tried to send a long message but it wouldnt go . Today is another day so here goes. Last year around Christmas I sent a reprint of a picture of Monaco dated 1920. Fred loved it . I checked my old PMs with Fred and found the mailing adress of his shop. It is Key Imports Ltd 2397 West Railway St Abbotsford BC Then I Googled the website for the shop and got his email and phone number the number is 604 853 5171. A few days ago I emailed him at the shop and have received no reply Monday I called the number . No answer and I left a message for Fred but I have heard nothing back. Maybe the shop is closed for the holidays but around here most repair shops are open except for the official closing daysNext I checked the obits for 2019 in Abbotsford Fred did not show up there which was good . Bit of a goulish job.I'm pretty sure hospitals wont hand out information so thats out . I'm going to check the Better Business Bureau in Abbotsford and also I will check other businesses on Railway St . Repair shops or Machine shops . Fred must be well known in town and the place isn't that big so somebody must know something . If anyone who is good with computers wants to do some checking too please feels free to do so Anyway this will give all his friends who are concerned some leads to follow up on . Merry Christmas to everyone
I spoke with Rob at Mastertek just down the street from Fred's shop this afternoon. He said that he remembers seeing him not that long ago but that he would walk down to the shop to check on Fred and asked me to call him back after the Jan 1st holiday.
Hey Phil . That is great . I sent an email to Mastertek this afternoon asking if they knew the whereabouts of Fred etc and was hoping to get a response sometime soon. Hopefully we will get some news
I spoke with Rob at Mastertek today and he check at Fred's shop after I spoke with him but he wasn't around. I got a call about an hour later from someone who was in Rob's shop and knows Fred well. He advised me that he sees Fred regularly and Fred is alive and well although he's had a few bouts with the flu. He told me that Fred recently spent two weeks in Mexico. I asked that he tell Fred that we were inquiring about him. Good to hear that he's OK.
Thanks, Phil!
Good News!
Good news,
Now we need some updates
An update on DiDueColpi, otherwise known as Fred. Good news, Fred is alive and well! I had a long conversation with him late this afternoon (BC time). He and Mrs. Key took a 2 month holiday in Europe, swore off electronics for the trip and says that he hasn't got back into the swing of posting things since his return.
He is still working on some of his projects and said that he will be posting again in the future but that he has enjoyed the freedom from the internet.
I have missed following him and his projects on this site.
Phil
Great News! Thanks, Phil!
It would probably do most of us a world of good to spend less time on electronic distractions. Real life is out there & it is not waiting...
Well The mystery is solved Way to go Phil aka Sherlock ps how did you get him to answer a phone?
Hi Fred!
How's that Unicorn coming along?
Bump for Fred?
I've been looking at going down a similar path with an engine build, as described in this thread.
I've been looking for piston/rod combos that work with the 28cc rover head, and either a 4.0, 4.6, or offset ground 4.6 crank. Using a custom spreadsheet, the best results come pistons with low 20's dish cc's, short piston heights, and 6" or longer rods as needed. Some combos offer mid-10's compression, 40thou squish/quench (does the perimeter ring quench matter with a dished piston?), and over 1.8 rod ratio. JE makes some, but they're not plug-in easy -different pin sizes, etc. and they're pricy.
Using the 305 pistons and rods, using -12 to -14cc pistons I can get a reasonable compression, but the piston needs to be way down in the hole, like over 80thou. I've been assuming about 3cc's of extra volume for combustion chamber porting work.
What trade offs would you go with? Grind the combustion chamber some (lots) more, or give up on getting a decent quench, to use off the shelf parts?
If you need more combustion chamber use the Buick 300 heads.
I have spent many, many hours over the years playing with the various combinations using the calculators below. I have come to the conclusion that it is most likely cheaper & certainly easier just to bite the bullet & buy custom pistons rather than try to use off the shelf pistons.
https://uempistons.com/rt-4-calculators.html
"use the Buick 300 heads"
I've been looking around for some, but haven't seen any in the last several months in the places I know to look. (some came up on eBay maybe two months ago, with an intake, for around $1k. I thought that was steep. Before I was really looking, I saw some earlier in the $300 range, which I'm kicking myself for not getting...) Where do the people on this site find them??
Brian McMillan has quite a few parts to sell. He will probably post here and on the Mgexperience site.
It is worth noting that the SBB iron heads are just 35 lbs heavier than the aluminum 300 heads for the pair. They also have larger ports and valves. I have a set of iron heads on the Buick 300 currently in my '71 MGB which I just drove to the V8 meet and was quite satisfied with the performance. It was just about what you would expect from a stock 9:1 compression 300 ci engine of that era, specs are 210hp@4600rpm and 310ft/lb@2400rpm but with the EFI and equal length headers I'd say it was doing a little better than that. Not a racy sports car engine but I gotta tell you it is a vast improvement on the B series, very easy to drive (have still never stalled it once) and has a ton of performance potential. All that's needed to raise the redline a bit is a stiffer set of valve springs, and a step up on the cam can get you into the 6K territory. I wouldn't push the stock pistons much past that but hp should go up accordingly and get you well into the mid or upper 200's. That's good performance for little money.
The weight is a non-issue unless you are racing, but if you feel the ride height needs adjusted upwards these folks may have a spring spacer that will do the job.
https://www.suspension.com/universal-coil-spring-isolators.asp
We made 1" spacers for the Roadmaster with the 455 and used Moss 1" lowered competition springs IIRC and that worked out well on a GT that weighs in at about 2700lbs with the BBB, T5, and Jag IRS. Note: due to the 2:1 ratio from tire to spring 1" of ride height = 1/2" of spring height.
Jim
I've started machining a raw forging. This will take a while. Art.
The block has been machined for quite a while now. just haven't been down to pick it up.
Once the resto on the 65 Elan is finished I'll get back to the Rover engine.
Oooops sorry, the lovely Lynne says the boat motor gets built next. Just a normalish 350 sbc ;-) won't take long at all.
Cheers
Fred
Just for info, the top hat liners are made by Westwood cylinder liners. £300 a set here in the UK from Britpart distributors.
My 4.6L block is a later version form 2002. The liners in it sit on a step at the bottom to stop slippage but it's still possible to get a crack behind, although these blocks are supposed to be the most resistant to it. The liners are stock AFAIK but do appear to be either thicker than 'normal' or have some form of top hat on as they measure 101.5mm across the top.
Duncan at Westwood (a very helpful chap) says this is a bit odd as top hats are wider than this and orginal liners are narrower...
Richard, The liners in this thread are GM. Maybe in your case someone put your liners in upside down like mentioned early in this thread?
FWIW , I called Summit today, they say sleeve is .060" wall. Seems too thin ? How about Hylomar at bottom of liner ?
Outdide of sleeve might get wet, in some spots. Onward, Art.
A valvetrain revolution is coming. Fred K., do you see it ?
Onward, Art.