ushes Posted March 10, 2009 Report Share Posted March 10, 2009 Has anyone had any experience with ARP conrod bolts ? I've removed the sump to change big end shells and discovered ARP 2000 conrod bolts with a Torx head. I intend to remove the external feed to the rockers whish I think caused the shells to expire prematurely. Anyway, it's a high spec engine, lightened, balanced, stage2 head ported gas flowed, racestorations exhaust etc. etc I'm reluctant to re-use the bolts but at around £80 a set they're not cheap. Bearing in mind its a road car and I only do in the region of 2-3k miles per year. Where would I get some replacements if needed and what torque figure should they be tightened to ? Many thanks Regards Steve Quote Link to post Share on other sites
foster461 Posted March 10, 2009 Report Share Posted March 10, 2009 Has anyone had any experience with ARP conrod bolts ?I've removed the sump to change big end shells and discovered ARP 2000 conrod bolts with a Torx head. I intend to remove the external feed to the rockers whish I think caused the shells to expire prematurely. Anyway, it's a high spec engine, lightened, balanced, stage2 head ported gas flowed, racestorations exhaust etc. etc I'm reluctant to re-use the bolts but at around £80 a set they're not cheap. Bearing in mind its a road car and I only do in the region of 2-3k miles per year. Where would I get some replacements if needed and what torque figure should they be tightened to ? Many thanks Regards Steve Steve, I would expect the bolt torque to be set my the bolt manufacturer. I'm pretty sure the uprated bolts I bought from Goodparts ($36 for a set of big end bolts) came with torque instructions. Does this engine have fancy rods and pistons also ? Stan Quote Link to post Share on other sites
TIMS Posted March 10, 2009 Report Share Posted March 10, 2009 Steve Have a look around this, up and down a page or 3 to see if it helps. http://www.arp-bolts.com/catalog/Catalog.html Regards Tim Quote Link to post Share on other sites
ushes Posted March 10, 2009 Author Report Share Posted March 10, 2009 Mmmm, thanks for the link, not much info on conrod bolts though. I'd imagine the distributor (maybe I'll speak to Burton Power) would advise. I didn't build the engine and this is the first time I've needed to do anything with it. I was given the spec which I need to look at it more detail. I think it has 'modified and strengthed' rods and pistons. In some of the documents I got with the car theres some literature for the TH5 cam, adjustable vernier timing and Carillo rods. I only have the sump off at the moment so I'll try and inspect the rods/pistons further and reply. Just to confuse matters, looking at some other forums for Fords, there are different bolts and torque settings for standard or Carillo rods. Thankyou Regards Steve Quote Link to post Share on other sites
TIMS Posted March 10, 2009 Report Share Posted March 10, 2009 Steve Er-Um Page 30 on Rod Bolts tells me that you probably have Pro Series ARP 2000 bolts ref 206-6005 And page 24 on Torque Specs tells me their stretch is 0.0060" with a torque of 42 Ft Lbs. Regards Tim Quote Link to post Share on other sites
ushes Posted March 10, 2009 Author Report Share Posted March 10, 2009 Apologies Tim, I was looking for conrod bolts in the index not rod bolts. Yes I suspect that you are correct. The head of the bolt does say ARP 2000, and the head type is 'E'. The engine was built by Manvers Triumph with Hepolite pistons and strengthened rods (peened maybe) As I mentioned earlier I intend to remove the external oil feed to the head, but it's not connected to the block where I expected to find it! Most diagrams locate it where the oil pressure switch is, however my switch is still fitted and the feed is right at the rear of the block under the metering unit, is it fed from the rear main bearing cap? I suspect I need some sort of blank there instead. If I can get the hang posting pics I'll post a couple of the big end shells. Many Thanks Regards Steve Quote Link to post Share on other sites
PJM Posted March 10, 2009 Report Share Posted March 10, 2009 Page 88 makes interesting reading. Permanent stretch of 0.001 and they should be changed so presumably if they are less than that they can be reused? I suppose it depends on how much it is worth taking a risk for the sake of a few quid on bolts Quote Link to post Share on other sites
foster461 Posted March 10, 2009 Report Share Posted March 10, 2009 Page 88 makes interesting reading. Permanent stretch of 0.001 and they should be changed so presumably if they are less than that they can be reused? I suppose it depends on how much it is worth taking a risk for the sake of a few quid on bolts A buddy here rebuilt his TR4 engine over the winter. It ran fine for 10 mins before it went bang and stopped. One of the (new) rod bolts had pulled out of the rod and the result was a dead rod, piston and liner. It looks like the thread in the rod had stripped as there was nothing apparently awry with the bolt. Stan Quote Link to post Share on other sites
Eyetee Posted March 10, 2009 Report Share Posted March 10, 2009 Just took the sump of my race engine this evening and I am also faced with ARP 2000 bolts on the big ends, also going to replace big end barings for the new season, my engine was prepared for the previous owner by Mike Entwistle, pleasing so far, Carrillo rods, I think Omega pistons Has also suggested while engine apart relapping the valve seats, so alos doing that. I dont see how an external feed to the rockers would cause the big end damage? I would scrutinize the crank grind and big end barings sizes. Did you find any debrize in the sump? Other than big end barings. I wasnt going to replace the ARP bolts, might have to now in the light of this post, thank you Quote Link to post Share on other sites
foster461 Posted March 10, 2009 Report Share Posted March 10, 2009 Just took the sump of my race engine this evening and I am also faced with ARP 2000 bolts on the big ends, also going to replace big end barings for the new season, my engine was prepared for the previous owner by Mike Entwistle, pleasing so far, Carrillo rods, I think Omega pistons Has also suggested while engine apart relapping the valve seats, so alos doing that. I dont see how an external feed to the rockers would cause the big end damage? I would scrutinize the crank grind and big end barings sizes. Did you find any debrize in the sump? Other than big end barings. I wasnt going to replace the ARP bolts, might have to now in the light of this post, thank you I think the theory is that the external oil feed robs the engine of lube to the bottom end (as well as potential flooding at the top end). Stan Quote Link to post Share on other sites
Guest ntc Posted March 10, 2009 Report Share Posted March 10, 2009 (edited) I think the theory is that the external oil feed robs the engine of lube to the bottom end (as well as potential flooding at the top end). Stan Hi Not so in a race engine and it looks like it is are you useing roller rockers?Eyetee Neil Edited March 10, 2009 by ntc Quote Link to post Share on other sites
Eyetee Posted March 10, 2009 Report Share Posted March 10, 2009 I understand that roller rockers are weaker at higher revs and therefore less suitable than origonal rockers for racing. They are also not FIA approved, but they do look good Quote Link to post Share on other sites
ushes Posted March 11, 2009 Author Report Share Posted March 11, 2009 The only mods to the rockers that I can see, is that it has solid spacers between the rocker arms instead of the standard springs and it also has alloy valve spring caps. The pedestals have a small copper shim underneath. According to what I've read this is to compensate for skimming of the head? I've emailed Manvers Triumph who built the engine originally to see if they can supply the correct conrod bolts and to ask their advice on the (unusually positioned) external oil feed to the rockers. I believe that Stan is correct, I suspect that there has been some oil starvation to the big ends due to the external oil feed. There subject has been covered in depth on the forum over the last couple of years. Regards Steve Quote Link to post Share on other sites
Andy Moltu Posted March 11, 2009 Report Share Posted March 11, 2009 If you've got good oil pressure and a decent oil pump the external feed probably won't starve the main bearing. However it's far easier to change a rocker shaft than the crank! Quote Link to post Share on other sites
TR 2100 Posted March 11, 2009 Report Share Posted March 11, 2009 (edited) The only mods to the rockers that I can see, is that it has solid spacers between the rocker arms instead of the standard springs and it also has alloy valve spring caps. The pedestals have a small copper shim underneath. According to what I've read this is to compensate for skimming of the head? That makes sense. Keeps the rocker geometry nearer to what it should be, and retains the normal adjustmen on the tappets, without shortening the push rods. Make sure the appropriate shim has the hole drilled for the oil supply if you do away with the external feed. I've emailed Manvers Triumph who built the engine originally to ask their advice on the (unusually positioned) external oil feed to the rockers. Explain? AlanR Edited March 11, 2009 by TR 2100 Quote Link to post Share on other sites
ushes Posted March 11, 2009 Author Report Share Posted March 11, 2009 Alan, from my earlier post. As I mentioned earlier I intend to remove the external oil feed to the head, but it's not connected to the block where I expected to find it! Most diagrams locate it where the oil pressure switch is, however my switch is still fitted and the feed is right at the rear of the block under the metering unit, is it fed from the rear main bearing cap? I suspect I need some sort of blank there instead. Regards Steve Quote Link to post Share on other sites
ushes Posted March 11, 2009 Author Report Share Posted March 11, 2009 I've just had a reply from my engine builder Cliver Manvers, regarding ARP bolts and the external oil feed, quote below for any interested parties. "Good afternoon Steve and thankyou for your email in respect of ARP connecting rod bolts. We retain these is stock at an individual cost of £7.62 each plus vat,making a collective total,excluding P & P of £91.44. Please let me know if you require these. We would not have fitted an external rocker feed kit to this engine,as in our experience and obviously well-founded by your own comments,this reduces the overall oil pressure. We therefore look forward to hearing from you in due course. Regards, Clive Manvers" I think thats good enough for me, definitely coming off Steve Quote Link to post Share on other sites
marvmul Posted March 11, 2009 Report Share Posted March 11, 2009 I digged out the paper that came with the 3/8 ARP conrod bolts (3/8 SPS-CARR) that came with carrillo rods for my TR3 race car : recommended stretch is 0.005 - 0.007" : WITH USE OF (ARP) MOUNTING PASTE under the head and on the threads. Carrillo recommend to determine the corresponding torque figure out of the engine : fixture one rod and first measure 2 bolts loose, then put the 2 bolts in a conrod, torque down alternatively the 2 bolts till you get the recommended stretch, write down the torque figure needed to get this stretch, use this torque figure for the final assembly of the rod bolts. I needed 45 foot/pounds to get 0.135 mm (about 0.0055") stretch and I used this figure for about 4 rebuilds of my engine, always with reusing the same bolts. Carrillo is stating that SPS-CARR bolts can be reused as long al they are not over torqued (max torque for 3/8" is 65 foot/pounds). On the same paper I found that instead of the ARP mounting paste brand, a Molybdene paste, mixed with engine oil, can also be used. PS : (3/8) SPS-WMC6 conrod bolts, sometimes deliverd with (Carrillo?) rods, cannot be reused, but the ARP type 3/8 SPS-CARR bolts can. Quote Link to post Share on other sites
Richardtr Posted March 11, 2009 Report Share Posted March 11, 2009 Has anyone had any experience with ARP conrod bolts ?I've removed the sump to change big end shells and discovered ARP 2000 conrod bolts with a Torx head. I intend to remove the external feed to the rockers whish I think caused the shells to expire prematurely. Anyway, it's a high spec engine, lightened, balanced, stage2 head ported gas flowed, racestorations exhaust etc. etc I'm reluctant to re-use the bolts but at around £80 a set they're not cheap. Bearing in mind its a road car and I only do in the region of 2-3k miles per year. Where would I get some replacements if needed and what torque figure should they be tightened to ? Many thanks Regards Steve If you could do only 2 things to your engine first would be fit ARP Con-Rod bolts, second would be fit ARP Flywheel bolts. I think you will find the heads are 12 point Go to website for how to install stretch bolts http://www.arp-bolts.com/index.html Also Arrow see below they will be able to give Torque figure Arrow Precision Engineering 12 Barleyfield Hinckley Fields Ind Est Hinckley Leicestershire LE10 1YE England tel: +44 (0) 1455 234200 fax: +44 (0) 1455 233545 e-mail: enquiries@arrowprecision.com web: www.arrowprecision.com Quote Link to post Share on other sites
ushes Posted March 12, 2009 Author Report Share Posted March 12, 2009 Just a bit of info for anyone who's interested. Rally Design supply the correct APR bolts at £61 a set if ordered online, +vat & p&P. £81 delivered in my case. Would anyone like an external rocker feed kit..... Or would anyone have the correct plugs I need to plug the oil feed holes, one at the rear of the head and one at the rear of the block, maybe from an old engine ? Thanks Regards Steve Quote Link to post Share on other sites
ushes Posted March 12, 2009 Author Report Share Posted March 12, 2009 Pics of the offending big end shells. My opinion is oil starvation, any comments ? Although the scoring looks severe, they're perfectly smooth to the touch and the crank looks fine. Cheers Steve Quote Link to post Share on other sites
peejay4A Posted March 12, 2009 Report Share Posted March 12, 2009 I'm no metallurgist but, apart from the obvious scoring, it looks like there's some smearing of the white metal which could perhaps point to dry running. Quote Link to post Share on other sites
Mike C Posted March 12, 2009 Report Share Posted March 12, 2009 Steve, You wouldn't have raced the engine at start up, before the bearing oil films were established?In a hydrodynamic bearing the oil pressure establishes a film that prevents metal to metal contact.Its the film and not the oil pressure itself that prevents the contact.I believe that it is good practice to wait for pressure on the gauge to ensure oil delivery to the bearings then add an additional few minutes for the film to establish. I have seen this wear pattern on passenger car bearings that were operated as daily drivers, just started and run. Regards, Quote Link to post Share on other sites
ushes Posted March 12, 2009 Author Report Share Posted March 12, 2009 To be honest the car is little used, and after standing for a while it takes a bit of cranking before the fuel gets through. Probably by the time it actually fires the oil pressure would be there OK. I would normally have a couple of minutes easydriving in lower gears before joining a main road so the oil pressure should be but OK by then but I do take your point. When warm however I do use the power available, like most owners I guess. I do around 1-2k summer miles each year and change the oil at the start of each summer before using the car. The white metal is just beginning to deteriorate and I think I've caught them just in time. Symptoms were a barely noticable clack clack when engine was very hot, but quiet otherwise. I suspected thrust washers but clearance was only 10 thou but I've changed those anyway, now back to 8 thou. I only took the big end caps off for a quick look to check that all was well, pleased I did now. Thanks for all of the replies gentlemen. Regards Steve Quote Link to post Share on other sites
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