3.9 RV8 Twin Turbo MGB - Updated 10th March '09
Moderator: phpBB2 - Administrators
-
- Top Dog
- Posts: 2334
- Joined: Sat Aug 18, 2007 5:09 pm
- Location: Sidcup, Kent, UK
Hi Kevin,
The pistons that I have are 3.5l bore, with standard 3.5 grudgeon pins as they are currently on some standard rods. I only have 7 of them though so I'm gonna get in touch with cosworth and see if I can get an 8th one to match, but for the price I paid it would have been stupid not to they we're practically free. The part number is PA0470/1 and I believe they are about 8:1 comp ratio. I've got another set of high comp ones that came with the group a rods I have just got, part number PA0753/1, which I have for sale in the classifieds as they're to high a comp ratio for me and the guy wanted to sell them as a set with the rods.
The low comp ones have standard grudgeon pins, but the high comp ones have floating pins with cir-clips. I already have a newly balanced crank, so I'm just a piston short of the rotating assembly, planning on building a super strong 3.5l and whacking a hell of a lot more boost through than the 5-6psi I'm running in the 3.9 I have at the moment. Have a small matter of a block to buy tho first!
The pistons that I have are 3.5l bore, with standard 3.5 grudgeon pins as they are currently on some standard rods. I only have 7 of them though so I'm gonna get in touch with cosworth and see if I can get an 8th one to match, but for the price I paid it would have been stupid not to they we're practically free. The part number is PA0470/1 and I believe they are about 8:1 comp ratio. I've got another set of high comp ones that came with the group a rods I have just got, part number PA0753/1, which I have for sale in the classifieds as they're to high a comp ratio for me and the guy wanted to sell them as a set with the rods.
The low comp ones have standard grudgeon pins, but the high comp ones have floating pins with cir-clips. I already have a newly balanced crank, so I'm just a piston short of the rotating assembly, planning on building a super strong 3.5l and whacking a hell of a lot more boost through than the 5-6psi I'm running in the 3.9 I have at the moment. Have a small matter of a block to buy tho first!
-
- Top Dog
- Posts: 2334
- Joined: Sat Aug 18, 2007 5:09 pm
- Location: Sidcup, Kent, UK
Thanks Ollie, I thought they were for the 3.9 large bore block as when I was looking for a full flat piston top for my new engine I could not find any without having them specialy made which would have been cost prohibitive.
The nearest I could get was a set of Keith Black Hypereutectic cast pistons with 5cc cutouts which I got from Summit in the states for only £180.00 ! They also do a dished piston which would give a lower compression ratio with a bore size of 94.89mm so you need to have the block bored and honed and you need a set of Chevy con rods at £250.00 to match the larger gudgeon pin.
Hopefully my new 4.35 engine is going into the car in the next few days.
Kevin.
The nearest I could get was a set of Keith Black Hypereutectic cast pistons with 5cc cutouts which I got from Summit in the states for only £180.00 ! They also do a dished piston which would give a lower compression ratio with a bore size of 94.89mm so you need to have the block bored and honed and you need a set of Chevy con rods at £250.00 to match the larger gudgeon pin.
Hopefully my new 4.35 engine is going into the car in the next few days.
Kevin.
-
- Top Dog
- Posts: 2334
- Joined: Sat Aug 18, 2007 5:09 pm
- Location: Sidcup, Kent, UK
Well I'm well confused now. Looking at the low comp pistons, they have standard rods and use circlips - the pistons even have a little grove in them for the clips.
The high comp ones don't have circlips or any groove for them, and using the group A rods, the grudgeons do move a bit but seem well secure?
All the rods are bushed, yeah.
The high comp ones don't have circlips or any groove for them, and using the group A rods, the grudgeons do move a bit but seem well secure?
All the rods are bushed, yeah.
- Ian Anderson
- Forum Contributor
- Posts: 2396
- Joined: Sun Nov 19, 2006 9:46 pm
- Location: Edinburgh
I believe you then need teflon buttons at either end of the pin
The teflon stuff will not score the bore if / when the pin moves
Ian
The teflon stuff will not score the bore if / when the pin moves
Ian
Owner of an "On the Road" GT40 Replica by DAX powered by 3.9Hotwre Efi, worked over by DJ Motors. EFi Working but still does some kangaroo at low revs (Damn the speed limits) In to paint shop 18/03/08.
-
- Forum Contributor
- Posts: 3979
- Joined: Sat Nov 18, 2006 6:22 pm
- Location: Northern Ireland
MGB 3.9 RV8 Twin Turbo - New pics
Ok some updated pics;
Trigger wheel and VR sensor
Nearside turbo;
Home made battery box, mounted to original MGB battery access plate;
Engine bay mock up, without intercooler/turbo pipes (not ordered them yet!);
Inside boot (old photo);
Trigger wheel and VR sensor
Nearside turbo;
Home made battery box, mounted to original MGB battery access plate;
Engine bay mock up, without intercooler/turbo pipes (not ordered them yet!);
Inside boot (old photo);
-
- Forum Contributor
- Posts: 3979
- Joined: Sat Nov 18, 2006 6:22 pm
- Location: Northern Ireland
you're telling me mate! I've changed the position of a few thinsg at the front since the lat photos, namely the oil breather and oil filter. And that's not including the 6 pieces of pipework and custom plenum!
Bracket was made from 3mm alu, I've got some 4mm mild steel that should be ok then, will use the alu bracket as a template. Took me over an hour to make that and get it in position right! Typical
Bracket was made from 3mm alu, I've got some 4mm mild steel that should be ok then, will use the alu bracket as a template. Took me over an hour to make that and get it in position right! Typical
god i gota get my arse in gear and do something about turboing my ole gal.
nice install mate,
nice install mate,
Regards Tony C (COOPS)
MS2 V3.57 Ecu mapable efi and wasted spark ignition.
Procharger D1SC supercharger and Cossie RS500 Intercooler @ 14psi of Boost. 416 RWHP, (boost leak)
Forged 4.8 V8 kitted out with the dogs Cajones of parts.
Sponsored by: www.v8performanceparts.co.uk, www.interpart.biz, www.caprisport.com & www.baileyperformance.co.uk
MS2 V3.57 Ecu mapable efi and wasted spark ignition.
Procharger D1SC supercharger and Cossie RS500 Intercooler @ 14psi of Boost. 416 RWHP, (boost leak)
Forged 4.8 V8 kitted out with the dogs Cajones of parts.
Sponsored by: www.v8performanceparts.co.uk, www.interpart.biz, www.caprisport.com & www.baileyperformance.co.uk