Project engine!!!!!

[Azman]

Right guys here's the plan.

Can someone aid me with a shopping list so I know what to go for.
The aim is 500+BHP

I will be using and rebuilding my 7A block to use with my 3B head which has been rebuilt (whilst in WAB's hands). What do I need????

I have a list but can you guys add to it or make it a bit stronger/defined for me.


1. Crank shaft - possibly knife edge
2. Rods
3. Piston Heads dished to lower the compression of the 7A block.
4. Metal Head gasket
5. Turbo - bigger
6. RS2 EM
7. Reversed inlet (so the intake does not run down the side of the head)
8. Intercooler
9. RS2 Injectors
10. Fuel Pump

Now I start to drift away.

Is there much machining of the block required to get the head to match or am I just waisting my time with this??????
Is there anything else to add, Can I make anything stronger to take the pounding?

Any advice here so I can build my shopping list and look into prices would be good.

Cheers Guys

Aaron

(I know it's only just gone in but as I have a 7A block handy I may aswell abuse it:mischeif: )

[Erikb]

I dont think its a good choose to go for a rs2 em and rs2 injectors if you are aiming above 500 hp, they will not be up for this job. You will need a turbular EM and some bigger injectors. I bought a 044 bosch fuelpump, which can handle this sort of output. If you want good cheap rods you can maybe join the next group buy for a set of SPM rods. For the pistons you can buy wiseco/ mahle / or JE. I believe you can also use the old pistons and skim something of.

I dont know what kind of ignition you want to use, I am changing my 3b wireloom and computer for a rs2 one. Besides that I also made an ignition harness to use 1.8t coilpacks.

Have you already thought about the gearbox and the exhaust?

If you want to use a bigger intercooler and a front mounted IM you also want to have a custom xmember and some samco hoses.

Dont forget to change the rod bearings if you open your block.

good luck!!

[Corey]

1. Crank shaft - possibly knife edge
2. Rods
3. Piston Heads dished to lower the compression of the 7A block.
4. Metal Head gasket
5. Turbo - bigger
6. RS2 EM
7. Reversed inlet (so the intake does not run down the side of the head)
8. Intercooler
9. RS2 Injectors
10. Fuel Pump

11. ARP head stud kit
12. ARP main stud kit
13. junk standard pistons and fit forged.
14. junk No. 6 and fit a tubular
15. GT3071
16. junk No. 9 and use GT3 injectors.
17. clutch to cope with it all.
18. have the head ported and polished.

after a very long day underneath a car this is all my mind will let me think of, I am sure there are other parts to add to the wish list that I will think about in my sleep but that's enough for now.

[Dutch_RsBlueS2]

11. ARP head stud kit
13. junk standard pistons and fit forged.

Nah, disagree at one point, if the bores are good enought just stick to original pistons. Skim top, and use multilple gaskets to lower CR.
Heard some good stories about standart pistons with 6xx+hp.

But this just counts if bores are good enough, you will only need honing + new pistonrings.

Cheers Cees

[volcano rs]

agree with cees standard pistons are forged and can handle good power

[Azman]

So there are some different views out there. Thought as much. Cheers so far guys, I will have to get 2 lists sorted, one for the whole hog and the other for the original pistons route.

Cheers so far but keep em coming.

Cheers

Aaron

[Jon441cc]

I thought that 7A pistons were cast not forged.

[Mark Halligan]

If you are planning on having a good old spend up, then you could use Javad Shadzi's 7A engine build as a guide to follow.

His company 034motorsport do all the go faster bits you'll need to turbo the 7A, including a copper HG if you do have to bore to 83mm.
Don't dive in have a good research and weigh up your options.

If you can still use your original pistons with a thicker HG you'll save a few quid otherwise a set of JE's will set you back around £500 or so dependant on custom machining options (if any) and ring choice. But worth every penny

Good luck

[S2central.net]

Totally agree with Mark here that it would be foolish to rush into something on such an engine build. Must admit I dunno if 7A pistons are different material from the 3B items. Dare say there are enough custom piston users around that you should be able to locate a set of used 20VT pistons.

My tuppence worth on other component choices -
The RS2 EM and injectors aren't going to cope with a 500bhp target. You'll need a custom tubular special or something like an 'S1' EM from MTM and clones.

For injector choice, the rule of thumb is they need to be comfortable flow 50lbs/min for the 'rail' pressure being used. The RS2 ones won't cope with that.

I'm not a big advocate of lowering compression ratio just for the sake of it. Yes you can run more advance with lower compression - but there is a trade off here. Suggest you get stuck into engine building books about understanding this stuff - you really should be measuring the chamber volums - not calculating them or just taking someone's word for it that a 4.25mm thick head gasket is correct for your needs. Then there's the static versus dynamic CR argument you need to get your head around with respect to camshaft choices.

A GT3071R should set you up well for a 500bhp target, but you need to provide more info about the kind of 'off-boost' performance you expect from this monster. What sort of mid range are you looking for ?

Also keep in mind this 'head porting and polishing' milarkey needs care - you only need highly polished smooth surfaces on the EXHAUST ports. Super shiny inlet ports are bad as they don't promote the mixture swirl that is needed for a happy engine.

As for knife edged cranks - that is very specialised work for very small gains in my opinion. Save your money on that and just make sure you get the bottom end dynamically balance by utter experts on these engines. Basset Down Balancing in Swindon have a great reputation for this and I used them in my days of blueprinting the odd GpN rally car engine (Not an Audi sadly).

Be careful with intercooler choice - there's lots of duff ones on eBay. Strongly suggest you plumb in an intake air temperature guage. Ideally you should have two - one at each end of the intercooler - then you can actually see how efficient it is (or not).

Reckon on additional instruments for a HiPo monster. The money saved on knifeedged crank will go well towards a Zeitronic datalogger for EGT, Boost & such. I'd also go for an electronic fuel pressure guage - so you can be certain your FPR is doing what it should be... Oh and 034EFI have nice adjustable FPRs that you can use with the 3B or 7A fuel system.

Paul

[Corey]

Nah, disagree at one point, if the bores are good enought just stick to original pistons. Skim top, and use multilple gaskets to lower CR.
Heard some good stories about standart pistons with 6xx+hp.

But this just counts if bores are good enough, you will only need honing + new pistonrings.

Cheers Cees

Personaly I wouldn't take standard pistons beyond 450hp and standard rods beyond 600Nm, especially if they have had some miles on them and then only with a trusted mapper.
I wouldn't want to put too much strain on "used" items either unless measured and found to be within spec.
If you have to buy new pistons because the originals have done either too many miles and/or worn they for the same (similar) money you may as well have the safety margin of uprated items. I mean how much would you save if the engine went pop?

Reliable hp costs money, sorry but I don't make the rules (although I do occasionally break them )

[S2central.net]

Can't argue with Corey's logic here really... Exotic new forged pistons and motorsport strength conrods are fantastic insurance for a heavily modified engine.

Remember it is TORQUE that breaks rods. Stock ones are good to 500-550Nm. Much more than that and you are on borrowed time. I haven't plotted the torque estimate for the GT3071R yet but I strongly suspect it is capable of bending stock rods if mapped accordingly.

Paul

[Corey]

I haven't plotted the torque estimate for the GT3071R yet but I strongly suspect it is capable of bending stock rods if mapped accordingly.

We shall see although the more I think about using the stock rods the more I think 2.5l with uprated pistons and rods. You only live once right?

[Mihnea]

What's the point in using GT2 injectors please??? 511cc/min and limited at about 500 crank PS, what's the point in paying Bosch prices?

Also, stock pistons are fine for whatever power levels really, as long as there is no detonation at all ever. Heck, I've tuned a few 400+ HP AAN engines in the US that had cast pistons and they don't have any problems, so I can't see any issues with running 500+ HP on forged 3B/ABY/ADU pistons...

[Mihnea]

ADU rods take 600 Nm all day long without a single problem by the way. One of the first ADUs that I have mapped to those torque levels (365 PS too) has just hit 50k miles of thrashing since being mapped and it's still running as strong as the first day I've mapped it.

[Mark Halligan]

As Paul mentoned Bassett Down Balancing are a good choice and will lighten the crank by around a kg before balancing the whole rotating assembly for you.