eastw77 Posted July 14, 2015 Share Posted July 14, 2015 Hi, I recently accuired a P76 V8 of unknown history. I have stripped the engine down and I have found it to be in poor condition with heavy scoring on the piston skirts, cam wear, a very slack timing chain and wear on the crank. My main worry though is at least 4 of the liners are not in line with the deck height and I am worried they have slipped. A picture say a 1000 words so here goes.. No.8 cyl main worry is bad area at approx 10 o'clock. No. 1 cyl similar. No. 4 liner sitting proud. No. 3 liner recessed. What do you guys think? Is this block worth bothering with? I also have a 3.9 rover stripped in the shed with a good block but the crank is toast. Is it possible to fit the p76 crank to the 3.9 block i.e grind the main brgs down to rover size or line bore to P76 size, which wold be the best option? Does anyone know of any rods which would be suitable if I used the 3.9 Pistons with the P76 crank? Quote Link to comment Share on other sites More sharing options...
need4speed Posted July 14, 2015 Share Posted July 14, 2015 That block needs top hat liners. Then your good to go Quote Link to comment Share on other sites More sharing options...
Cheesy Posted July 14, 2015 Share Posted July 14, 2015 Hi, I recently accuired a P76 V8 of unknown history. I have stripped the engine down and I have found it to be in poor condition with heavy scoring on the piston skirts, cam wear, a very slack timing chain and wear on the crank. My main worry though is at least 4 of the liners are not in line with the deck height and I am worried they have slipped. A picture say a 1000 words so here goes.. No.8 cyl main worry is bad area at approx 10 o'clock. No. 1 cyl similar. No. 4 liner sitting proud. No. 3 liner recessed. What do you guys think? Is this block worth bothering with? I also have a 3.9 rover stripped in the shed with a good block but the crank is toast. Is it possible to fit the p76 crank to the 3.9 block i.e grind the main brgs down to rover size or line bore to P76 size, which wold be the best option? Does anyone know of any rods which would be suitable if I used the 3.9 Pistons with the P76 crank? You would probably be looking at rods and pistons to get it to work, it looks like they have been done by both methods (grinding or line boring). There is a guy in Christchurch that made a new long stroke crank and pistons to fit in the 3.5 block to take it out to around 4.5. If you do find a good piston/rod combo post it up Quote Link to comment Share on other sites More sharing options...
garrycol Posted July 15, 2015 Share Posted July 15, 2015 The 4.4 P76 engine is not a good engine and cannot handle revs - I would ditch it and get a RV8. Google the P76 engine on AULRO and other forums and you will see the issues. Quote Link to comment Share on other sites More sharing options...
Cheesy Posted July 18, 2015 Share Posted July 18, 2015 You might have more luck by talking to a engine builder who has been around for a while, chances are there were a lot of these sort of conversions done in the 80s and it seems nothing from the 80s made it onto the net. I dont know who is up your way but Im sure someone like Gavin Hill in Chch could give a run down on options and viability of doing this Quote Link to comment Share on other sites More sharing options...
eastw77 Posted July 18, 2015 Author Share Posted July 18, 2015 Thanks guys, yes I think I will be looking at new rods and Pistons. I have a few names of guys to contact for advice. I will post up what I end up finding out. Quote Link to comment Share on other sites More sharing options...
Ash.Witty Posted July 18, 2015 Share Posted July 18, 2015 The block is essentially a 3.5, and has a mega stroked crank to take it to 4.4. 3.5- 88.9mm bore 71mm stroke A 3.9 uses the same crank as a 3.5, just 94mm bore. P76 4.4- 88.9mm bore 88.9mm stroke I think you could build a bigger beast by using the crank and rods from the P76 in the 3.9 block, I'm not 100% sure but if the gudgeon pin is at the same height from the crown it could all go together.... 3.9 94mm bore and 88.9mm p76 crank would make 4931cc Quote Link to comment Share on other sites More sharing options...
Ash.Witty Posted July 18, 2015 Share Posted July 18, 2015 Might be worth measuring the block deck height as well, I've been googling but I can't find the info.... From pictures it looks a bit different. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted July 18, 2015 Share Posted July 18, 2015 I am sure the block height is different on a P76, to fit RV8 inlets for example you use spacers between the manifold and head. Quote Link to comment Share on other sites More sharing options...
Cheesy Posted July 19, 2015 Share Posted July 19, 2015 Yes the P76 block is around 17mm higher.... so you need a piston rod combo with a compression height that is about 17mm less than the rover setup. This is possible, the engine in mine has the longer stroke crank and custom pistons with RV8 rods in a 3.5l block. I was having a look at the ACL site this morning and it might be possible to use a Ford cross flow piston if they are available in a big enough oversize. Quote Link to comment Share on other sites More sharing options...
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