istruggle2gate11 Posted August 13, 2007 Share Posted August 13, 2007 With the help of Nige I have now located an engineering shop that will undertake this work at reasonable cost and will also finish the bores to match my pistons …….. to be honest the guy gave me great confidence by asking all the right questions………I think somebody may have warned them that I’m a fussy bar steward. Ian Sorry to read about your troubles mate. If you dont mind me asking, what kind of price is it to have top hat liners fitted? (have a 4.6 sat in the shed, waiting for a rebuild) Quote Link to comment Share on other sites More sharing options...
fisha Posted August 13, 2007 Share Posted August 13, 2007 If you dont mind me asking, what kind of price is it to have top hat liners fitted? Ditto . . . theres the odd wee noise from mine which i wonder about sometimes. Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted August 15, 2007 Author Share Posted August 15, 2007 OK…………….. so to recap on the above posts………… The diagnosis of coolant to combustion chamber / bore failure on No1 cylinder is based on the following evidence, The coolant smells strongly of induction /exhaust gases ……….. this characteristically smells like a very , very rich exhaust gas ………….. no need for a chemical test when your nose is giving the correct answer ……… siphon a little coolant off into a clean vessel to double check with the ‘hooter’ test. Also the coolant was pressurising to much greater then 15 psi………. On any petrol engine the plugs are one of the most reliable sources …………. If you can read a plug then you will be able to detect most faults with little effort …… No 1 is on the left and No 3 is on the right …………..No1 plug is clean and looks like it has been steam cleaned ………No 3 shows that I was just beginning to get the tuning correct ! ………… dark grey on the rim and a brown nose. The compression tests (see post 139) show that the head gasket is probably Ok …… this only leaves the option that the coolant is entering No1 pot via the liner ……. The engine has now been removed and the heads stripped off to confirm the above diagnosis ……………… picture are worth a thousand words …… This is the lefthand head …………. No1 combustion chamber shows the problem is all its glory …………. Steam cleaned with no carbon deposits……The head gasket is absolutely mint, so the compression test was not telling porkies. Its now time to take a close look at the liner ……………….. the two pictures show that this liner has no slippage whatever …………. I spent about 2 hours last night taking measurements and if it has slipped then it is less that one tenth of a thou …..0.0001. You can clearly see the chamfered top edge of the liner sitting nicely level with the block face. close up………… I think this serves to show just how difficult this fault is to detect from just visual inspections …………….I would suggest that there is a crack in the coolant jacket behind No1 liner and toward the top of the bore ………… once the engine gets hot then the aluminum will expand just a little more than the liner allowing compression gases to be forced between the liner and the block ………… once pressurised the coolant will escape back into the bore on the non compression strokes ………….. also a good test to see if this is happening, is to stop the engine whilst hot, wait for a few minutes and then restart ……….. this restart will be accompanied by a slight misfire followed by a cloud of grey / white smoke as the bore clears itself of coolant……….. The engine will now be completely stripped and the block relined with ‘Top Hat’ liners….……..this will cost between a monkey and a grand ………. but as the engine can to me free, then its no big deal……….. Ian Quote Link to comment Share on other sites More sharing options...
q-rover Posted August 15, 2007 Share Posted August 15, 2007 but as the engine can to me free, then its no big deal……….. Ian Again that begs the question why not do that to start with? Good luck... Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted August 15, 2007 Author Share Posted August 15, 2007 Again that begs the question why not do that to start with?Good luck... I guess it comes down to the fact that this fault rarely happens on the 'outer' pots .......... normally the inner pots (3, 5, 4,6)............ a visual showed that all seemed in order and there was nothing other than none to recent headwork, to suggest anything was amiss...............to be honest there are many, many, 3.9's out there with moon mileage that have not suffered the porous block syndrome ....... When all said and done, the V8 is not a complex engine to strip & build ........... Ian Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted August 28, 2007 Author Share Posted August 28, 2007 OK ….let the build commence………… again.......... This is porn at its finest ……………… For those not exactly sure what top hat liners are, it should now be clear …………… the ‘fire ring’ ………. that’s the head gasket cylinder seal, now sits on the top hat of the liner and not the block, thus no cylinder pressure is placed where the liner and block meet………. Note the thickness of the new liners …………. about the same (may be more) as the old 3.5’s …… for comparison …………. Here is a pic of the std 3.9/4.2/4.6 liner, This is not a cheap option, although I feel it is money well invested as it provides a permanent solution to the problem. This has been CNC machined and CNC honed …………….. I checked the bores tonight and TBH they are perfection. The machining engineer has mentioned that it has been done the competition standards (which is what I asked for) and the break in process should be very short ……………. a couple of hundred easy miles, then ‘drive’ it to give the rings a final break in with no bore glazing. Rather than a generic +20 ……….the bores have been machined to match the pistons …….. Ian Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted August 30, 2007 Author Share Posted August 30, 2007 Just how many times have I mentioned on this thread that cleanliness is the secret to good engine builds …………I almost fell foul of that statement……… but not quite... Tonight I fitted the crank & pistons ……….. I had already made the decision for fit new main and big end shells as even quality shells are cheap………… may be just as well……….. When I inspected the shells on No6 piston I found a deep score mark for the full circumference of the bearing and it was scored right down to the copper backing. At first I was of the opinion that a bit of sh!t was to blame, but a close examination revealed a tiny (and I mean tiny) nick on the journal that left a sharp edge. Although the damage looks bad it would have had no real damaging effect on the engine life………… I am posting this just to show have careful you need to be ……… I inspect each journal as the assembly progresses …………. but I still missed that tiny nick . This has now been stoned and polished flat ……. The damaged pair are on the left and they should really look like the pair on the right…… just beginning to polish after about 100 miles ………… Ian Quote Link to comment Share on other sites More sharing options...
Les Henson Posted August 31, 2007 Share Posted August 31, 2007 Did you have the crank reground Ian? Les. Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted August 31, 2007 Author Share Posted August 31, 2007 Yes, the crank was ground at 10 / 10, and then polished ……………. I’m guessing that the slight damage was either caused in transit (in the back of my car) , or may of happened at the machine shop. Looking at the pics again, they tell a different story than reality ……………. the apparent score marks on all the shells are just areas that are beginning to polish, if left another 500 miles they would look polished and shiny as expected………… remember………. those shells have only done 100 careful miles………..the only score of note is just the one on the left hand shells…………… I tried to take a pic of the crank ………….. unfortunately the nick was so small that it couldn’t easily be seen in the pictures ………… but easily felt with the finger nail. Build progress is going well …………… I now have a short motor……… Ian Quote Link to comment Share on other sites More sharing options...
pugwash Posted August 31, 2007 Share Posted August 31, 2007 Ia, lovely work- who did the machining if you don't mind me asking? Did they just top hat the block or did they line bore the crank and cam journals as well? it's a realy sight for sore eyes though after all this diseasel talk Jim Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted August 31, 2007 Author Share Posted August 31, 2007 Jim, Yes, it is loverly work ....................... the block was CNC machined for a 5 thou interference fit with the liners. The liners were then CNC machine bored to match my pistons .............. then the bores were CNC Plato honed to a standard that I have not seen before .............. this engine will require no running in as plato honing has already more or less completed the process by removing all the high spots. It is important to bed the rings quickly to avoid glazing..... I checked the bores (cos I'm like that) ............... and the accuracy for the entire length of the bore is astonishing........ Also the block has been decked by 20 thou................so my CR will now be close to 11:1 The whole process is undertaken with the main bearing caps clamped to a solid bar............. once the bar is removed, then the mains were line bored to ensure that they are the true centre line of the block. The cam bearings had already been renewed .................. I did that on the original build with 'finished to size' clevite NASCARS............. Not cheap, but not excessively expensive either ............... money well spent IMHO Ian Quote Link to comment Share on other sites More sharing options...
Gromit Posted August 31, 2007 Share Posted August 31, 2007 is the top of the the liner proud of the deck, or recessed? Can't see how thick it is from the pics. Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted August 31, 2007 Author Share Posted August 31, 2007 The fire ring is level with (and now part of) the deck ..................... machined in one process............ Ian Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted September 2, 2007 Author Share Posted September 2, 2007 Well ………………… its all together now and just about ready to swing into the engine bay…………… It all went together pretty well, the main differences being that the piston deck height is now only 19 thou (due to the block being decked by 20 thou) …………… that measurement rather concentrates the mind on ensuring the valve timing is correct as I am not using cut out pistons. Initial checks indicate that the valve to piston clearance has gone from adequate to close…………. but it should be OK. This will put the CR at close to, or maybe exceeding 11:1. Another difference is that to get the lifter preload within tolerance, I now have the rocker posts shimmed out by 96 thou. The annoying downside is that the inlet manifold no longer matches the port alignment ……………. Its only a small error, but it also means that the manifold required a little reengineering to get it to fit. This will have a little adverse effect on gas flow, but I can live with it for now. When time permits, I will need to remove the manifold and have approx 15 – 20 thou machined from each mounting face………… also the OEM composite valley gasket will need to be modified. Ian Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted September 2, 2007 Share Posted September 2, 2007 I now have the rocker posts shimmed out by 96 thou Thats near to a washer Glad to hear its going back together, next time we meet I'll have me "Told you so" T Shirt on re the inlet manifold alignment, you can then smile ..and punch me....... Fair exchange Nige Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted September 7, 2007 Author Share Posted September 7, 2007 Just a short update ............................ the engine is now fully built and installed (again)............... It started straight away with no problems ................ an initial drive after some preliminary tuning was very satisfying................ It really feels like it wants to rev freely .................. so (unusually for me) at one point I just let it got to 4000+ rpm (for about 9 seconds) ............ my son was with me at the time ............... he turned to me with a big grithis was then followed by "remember, this thing only has Land rover Brakes !" I guess a little running and fine tuning is required ..................... then a trip to the rollers Ian Quote Link to comment Share on other sites More sharing options...
gav- Posted September 7, 2007 Share Posted September 7, 2007 can i just thank you for this detailed thread, I have 4 v8s sitting awaiting overhaul maybe start on one now Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted September 20, 2007 Author Share Posted September 20, 2007 I guess its time for an update ………………… not everything is plain sailing with a new engine ………………but at least now the coolant smells like coolant and I don’t have any steam cleaned cylinders ! It’s now done at least 500 miles, and I seem to have the general tuning almost there ………however there are still niggles to sort out before I submit it to the rollers. The overall performance can be described as ‘adequate’ …………….. it will pull cleanly from 600rpm in 5th right up to brown stain speeds…………..in 4th the acceleration is particularly impressive. B) I guess the icing on the cake is that I seem to be always looking for an extra gear ……….. i.e when in 4th I feel that I am in 3rd ………. In 5th it feels like the old 4th etc. Now here are the issues still to sort out ………………. When the engine has been stationary for a while (maybe 10 minutes - only on a hot engine) , an engine restart is accompanied by a puff of blue smoke. At first I though this was valve guides, but have now dismissed this, as overrun on log hills (max depression) does not burn any oil. My current thinking is that the high oil pressure (which creates a lot of rocker box oil mist) combined with the PCV methodology is leaving a small amount of oil in the PCV feed which then drains into to the plenum input when the engine is at rest (probably less than a thimble full). The engine does not use any oil, so this is more aesthetic as opposed to being a genuine worry. The other issue is maybe a little more complex ………… the fuel consumption is poor, so poor that normally to produce these sort of figures I would expect it to be abnormally rich, but that is not the case …………. Having discussed this with JU, the current thinking is that I may have some tach spikes that are causing extra banked injections …………….. Ian Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted October 11, 2007 Author Share Posted October 11, 2007 Hmmmmmmm…………………….. Today we played on a Dyno Dynamics 4wd rolling road ………. the results of which has both positives and negatives……….. Lets start by saying that the Dyno took extreme exception to my Super Swamper TSL LTB tyres …………..to be fair, Martin, who was running the session had warned me that the tyres may be a problem as he has had similar issues with comp safari racers running much less aggressive tread patterns. OK ……. yes……… the tyres were an issue for any definitive measurements ……… running up the dyno at my normal road pressures of 15psi produced a lot of mechanical vibration in the dyno and it was reporting 39 – 41bhp at the wheels ……………. Increasing the tyre pressures to over 40psi produced 130 – 140 bhp at the wheels but still the vibration was a problem. ……………….however as the estimated loss of the drive train and tyres in my case is 100bhp, the flywheel figures start to look encouraging. Martin did some further tyre tests and concluded that these particular tyres have a huge amount of drag (regardless of pressure)………… I guess that explains my very poor MPG figures…… Regardless of the numbers we were able to use the rollers as intended, to check out the fuel & spark maps ………. and this is where the positives come into play. 3 runs were made …………. then because Martin didn’t believe the fuel curve, another 3 runs were made with me altering the fuelling …………….. to cut a long story short my fuel map was about as good as it gets , showing an almost straight line graph …………… Martin informed that it normally takes a day or three of dyno time to achieve any close to that sort of mapping………… and on ECU’s costing 10 times as much (DTA’s etc) I think this really confirms that MS cannot be underestimated in its ability to perform, but to be fair, the tuning procedure I employed with MS was to use the road as a dyno !, however, only 8 wideband mapping logged runs were used to achieve this result. We then took further runs looking at the MBT (Minimum timing for best Torque) ….. again my spark map was spot on and required no further adjustment. Of great interest was the torque curve ……………. again this run was done a couple of times as it took some believing …………… the torque is good right off idle, and then it produces ‘ house moving’ torque from 1000rpm right up to 3200rpm ………. With a pronounced peak at 2400 – 2800 ……….we were showing over 160ft lb at the wheels…….however, it is thought the restrictive air filter is limiting the top end. So ………… the next move is to fit some round tyres that are road biased (probably AT’s) and maybe remove the front prop and the airfilter to get some definitive figures………….. The feeling of the operator is that its definitely well over 200 but probably less that 250 ……….. All in all, a good half day & time well spent………….. the issue with the tyres was a little disappointing, but that will be fixed in the very near future …………… oh .............and the engine sounds really sweet at 6,200 rpm Ian Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted October 11, 2007 Share Posted October 11, 2007 Excellent stuff Ian, I can imagine mud tyres are not ideal dyno material Any chance you could ping me a copy of your spark map (assuming it would be applicable on mine) to replace the "boosted" one you sent me? Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted October 11, 2007 Author Share Posted October 11, 2007 JU, Sent via email .................. the board will not allow me to upload a VEX file Ian Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted October 11, 2007 Share Posted October 11, 2007 Cheers Ian, I will stick it into my MSQ and upload for the benefit of other forumers B) Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted October 11, 2007 Share Posted October 11, 2007 Am I reading this right? Page 1 I said: >"Its quite plainly going to be putting out 226 BHPs." You said: ... produced 130 – 140 bhp at the wheels ... however as the estimated loss of the drive train and tyres in my case is 100bhp... If I'm interpreting correctly, we're looking at 230 - 240 BHP, so I'm 4 BHP out, right? That being the case, I repeat my question on page 1: >"Is this a nearest the bull question? What have I won? " Seriously - cracking thread B) , very nice work, and very interesting. Can't wait to see the final results (and receive my prize ). Can you just throw on a set of car tyres or something for the testing? Cheers, Al. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted October 11, 2007 Share Posted October 11, 2007 Can you just throw on a set of car tyres or something for the testing? I've got a set of 205 road tyres on RR rims in the garden you're welcome to borrow. Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted October 11, 2007 Share Posted October 11, 2007 As I said to you on the phone earlier Ian - Cracking result both for you, megasquirt,.....and me You - Nice thats its all come back together and as should be tunning wise Megasquirt - shows what a cracking bit of kit it is, not as 1st thought maybe of some whizzy kid of 14 designed in his back bedroom, I too have spoken to people who know about tunning - ie Mark Adams, and his comment was it it highly underestimated Me - Means that my Spark map is ok (thats what you have) and my VE MAP isn't far out either (thats yours) plus a load of NB Logging The MegaLogViewer and the NB tunning is just superb, I have yet to switch to WB but will when I have the exhaust done, will be very interesting to see what difference it makes to the table Time for you to have a celebratory drinky methinks B) Nige Quote Link to comment Share on other sites More sharing options...
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