Engine and Transmission Tech

Im in the process of building a new 4.6 for my car, Im looking for a reliable 330-40hp from it as well, Good quality pistons here in the UK are far too much money, around $1600US for what I want, so I have been forced to look elsewhere, 94mm/3.7" pistons are not that common, but after a ot of searching I had the choice of two that fitted my requirments,
1 was Ducatti bike pistons, Light, easy to get, and good quality, downside was they are virtually skirtless and starting to get expensive,
the other optionI had found was from a Ford Modular oversize engine, forged with a thick crown, forged, worked without any major machining other than valve cut-outs, and reasonably priced too, see link----
[cgi.ebay.com]
Used with 4.6 rods the comp ratio was a bit too low for my engine but with 4.0 rods and tin gaskets and 36cc chambers its up at a respectable 13.8-1 without cut-outs, the small ends of the rods need to be bronze bushed to fit the pistons, but thats only a minor mod, the other advantage I see with the 4.0 rods is the better rod/stroke ratio, especially as I favour long duration/overlap cams, and a longer piston dwell should help. apart from Chevvy rods and lifters, are there any other user friendly bits that can be used from other sources to make a better rover?? ARP SBF flywheel bolts are one, any more????
Ian



Edited 1 time(s). Last edit at 01/02/2010 12:10PM by v8ian.

Ian, I know several of the Buick guys are using custom made forged and paying around $900 US a set, occasionally I hear of sets going for around $400. Diamond is one brand worth looking into. I have $1100 or so in a set of Venolia's.

Jim

last set of Venolas I bought were a custom set for a 289W with 351C 2v heads, I think they were about $400US here inthe UK, but that was a LONG time ago!!!!

Hmmm.

So, the 4.6 Modular Ford guys have come up with a big bore option that happens to match the the bore of the 3.9/4.0/4.6 Rover? This could definitely be an interesting piston option.

Ian, So the std. 97 mm. Manley/Ford piston will allow you to," torque-plate hone", you're useds bores for 100 % clean-up? "Pink" block? Gap-less rings to fit? Flanged liners from the "other" Ian-Wales, are pretty reasonable.If you do your own machining, good way to save and you can un-shroud those silly little valves, not in the middle and open-up lots of piston options like 305" sbc's on the "cheep" or type IV VW./914 ? roverman.



Edited 5 time(s). Last edit at 01/02/2010 03:13PM by roverman.

I'm definitely a fan of those Modular pistons. I'm pretty sure the wrist pin dia is around 21mm or something like that. Just something to consider when looking for connecting rods. I suppose it's possible to bore out the piston for the SBC .927" pin but it's getting pretty close to the oil ring already.

I guess Eagle is due to come out with a "Honda" journal rod (1.89") for the 4.6.they'll come in 5.95" length. That could come in handy. The stock journal is something like 2.08" ish. The stock length is 5.933".

Roverman. My block has virtually no wear that I can find, It will receive a kiss with a hone to deglaze it and thats about it, Im going with the 3,7" pistons and Total Seal rings
Nick, Without going up the garage for a check, I think the Modular pin size is 0.880" and my rods from the 4.0 have a pin size of 0.9449" then bronze bush and hone my rods to suit, what bronze to use I dont really know to use,

I sorta need that information too. Is bronze bushings pretty common for connecting rod ends? It would help for my other project of marrying forged LS1 pistons to these Ford "Honda" journal rods.

The shops that sell rod cores and re-machining, use the bronze bushings, all the time and "should be" quite resonable. Make sure they put a, "smart" oil hole it the top ! Aftermarket is dirt cheep these days. Those"ProComp", 1,000 hp, 4340 billets with 7/16" ARP's were $275 set and will weigh approx 550 grams when narrowed,(large jrnl.6").Good luck , roverman.

Now the snow has gone, Im up the shed playing , Ive just done a quick mockup of my Rod/Piston combo, and its around where it was calculated to be obviously there are two compression ratios I can use, with the piston @ TDC 0,025" down the bore, and using the calcs based on 0.015" gasket, 36cc chamber, im getting 14.192CR, and with a 0.045" gasket 12.66CR, thats without putting valve cutouts into the equation, as they need to be calculated where and how big they need to be, does anybody need to ask what compression Im going to be running ------------------------------------------------14.192------------------------- But we do get 99ron fuel, and if you are rich 102ron, road legal fuel, BUT thats about 20$US+ per gallon!!!!!!!!!!!!!!!, 99s about10$US and normal unleaded is about 95ron and 8$US per gal, Nothing is cheap anymore, especially Fuel.

Ian, B-smart, starve the Oil Elitist ! I suggest a "peep" of "Performance E85" site and "V8 Buick" sites. E85 here is approx. 105 comparative octane and around $2.50 a gal. I further suggest your country consider, beyond buggy whips and sealing wax, of all things....roller cams! There-I said it, I feel better and so will you, "If "you give them a chance. If you do the conversion yourself, you could have as "little" as $400, us,(exclusive of VAT,FAT and Yazzir Arafat)? cam,lifters, dogbones and spiders.Cheers, roverman



Edited 1 time(s). Last edit at 01/17/2010 12:32PM by roverman.

E85 is not as far as I am aware easily available, trouble is, most of the price of fuel over here is TAX, well over 75%, as soon as they find out another fuel is popular, they whack on the tax, Diesel used to be half the price of Petrol/Gas, now its taxed to the extreme, and more expensive than Gas, People then started to convert cars to run on Propane, then all of a sudden, after there had been loads of conversions done, up goes the tax, Bit like chasing your tail, you are never going to win.
E85 as I know a couple of circuit racers that run it, BUT they have to buy it direct from the refiners.

Ian, yes but at least you have stellar medical care?/lol.? Over here, we pay, what "we" consider, lots of gasolene taxes that"used" to go for hiways and roads. They we're good then, but now our "elected" officials, use much of those funds for their pet projects! Av-gas , racing fuels are "exempted" from these taxes, for off-road use only. E85 is also exemted ,at least in Ca.,USA. Maybe if you and "others" buy racing fuels direct, the "Fat Cats" will learn to diet? LOL's in 2010, roverman.



Edited 2 time(s). Last edit at 01/17/2010 06:15PM by roverman.

Hey Ian,

Not sure if you guys have heard of this over there but, you might want to consider a "tea party"!

[www.probeindustries.com]
B.

Nice resourse, Bernard. I use this one periodically:

[www.flatlanderracing.com]

These guys have a great database of stock sizes:

[www.beckracing.com]

Ya know you made me take a second look at Probe. Really cost effective! The comparable JE's are $300 more. I'm sure the JE's are awesome but hey can't hurt to save a few hondo, right?

Here's something. I was looking at these Manley pistons:

[www.flatlanderracing.com]

And the "Honda" rods:

[www.flatlanderracing.com]

They are 408 g. and the rods are 525 g. Anybody know how much the stock rod/pistons weigh?