Tony_de_whitt

Ok engine guy re measured and realised he had made a mistake. compression ratio has been recalculated at 10.2 using the components above. all back on track and happy again. one final question is...- how can I tell if an engine block that was in the 99 outback hybrid model which has the new block old pistons. is such an engine??? if it has been removed. for example I have the chance to look through 26 short blocks. Is there a way I can tell which is the hybrid one. Piston makings?? block markings?? etc etc cheers ant

So I’m told standard 2002 ej25 standard pistons standard head gaskets ej22 heads with 8 thou taken off. thiughts on what compression ratio that should be thanks

What is the maximum compression ratio you could safely go with these engines?? thx

So in the end we didn’t have the choice to use exactly what we wanted. i will ask the engine man today. im pretty sure he has used standard pistons and a late block he had to take a fair bit off the heads is all I know and then did his calculations. Unsure if his method of calculating the ratio but he did mention using kerosene. is there an easy method to measure the ratio?? i will try and get some sizes of the parts he has used

Ok do we have advanced somewhat using the advice received in here. The guy who I am working on this with was keen to do a few calculations before assembly. this is the messsge he just sent me Hi Anthony, Compression ratio measured and calculated at 12,375 with standard thickness head gasket of 0.55 mm. Check on line and see what feedback you get it seems too high to me. Cheers Rob. So is this measurement possible?? is it too high?? should we reduce with thicker gaskets?? thanks again

Great thanks very much for all your time and sharing you knowledge much appreciated

Going well on all fronts apart from gaskets the ome 642 gaskets don’t have the same holes as the cometic and appears to block some of the passages any suggestions on altering etc?? cheers

Thanks Yes s i did read about using the 251 pistons. any ideas where they will sit in relation to the top of deck?? i thought using the .051 cometic head gaskets allowed for the 99 pistons to stick out of block and therefore give higher compression ratios. Which is is what makes the frankenmotor what it is. thanks again

So can anyone help with this final issue?? ive sourced a late block. 52mm journals etc etc we are using the cometic head gaskets .051 thickness when searching for the early pistons there seems to be a few different sizes to choose from. Can someone possibly confirm what size piston will work best and give the most compression but not cause me issues?? I’ve been looking at 1998 outback pistons with a choice of 2. and how far these pistons should sit in relation to the top of chamber?? Thanks again

Great info thx so just to clarify what con rods are used in this combination for the frankenmotor?? Do you have a part number or year of engine or length etc?? and if I’m buying new pistons do I ask for pistons from a 97/98 dohc outback. or do you have a piston part number. thanks again anthony

Any 25D engine or the 99 hybrid that people are talking about with new case old internals?? thx

Ok Pretty new to all this so apologies if I need spoon feeding. So I need the hybrid 99 model Ej25d or can it be any Ej25d?? swap out the pistons for 251,s what are 251 pistons out of?? 642 head gaskets I’m unsure what you mean? and which heads are you saying to use?? Are you saying just use the same heads and keep it as a complete Ej25d engine heads and manifold?? then swap all my electrics from my current Ej22 set up and put them onto the complete Ej25D engine. and my current wiring set up will run this engine fine?? also what sort or Hp would you get just using ej22 heads and a later Ej25 frankenmotor in comparison to the above set up?? appreciate your help on this thanks

Also read about some idling issues when changing cams. Is changing the cams vital?? thanks

Fergloyal Perfect ive got those heads and gaskets so now I need to find a 99 block just wondering what cars they were in in Australia is there a certain engine code I can look for ?? do the heads need altering to increase compression?? thanks

General Disorder i appreciate your knowledge and thanks for your reply. i think the sort of power your talking about is way above why I’m after its a frankenmotor I want and it’s the ej22 heads I’m going to use whatvim after is someone’s knowledge on what bottom end is best used to create a powerful frankenmotor maybe 160-180 hp. my old Vw engine was 90hp so effectively doubling it. with anything above 200hp I guess id rip my gearbox to shreds thanks