Twin turboing a 3.5 V8 sd1 Part 2
Discussion
Ok So Ive got my turbo exhaust manifolds with wastegates built in. They are to take rotomaster T04Bs. But as these seem to be hard to track down... it looks like im gona have to get me some T3's. But alas I'm confuddled. There appear to be so many variations of turbo.. eg www.rpmmotorsport.co.uk/turboproducts.htm. So what should I fit?
Chris
Chris
Talk to turbo technics. They supplied the T3 hybrid for der golf.
Tell them what power output you wish to reach(be reasonable..
), boost pressure max you'd like.
You may need to work out the flow rate of the engine at full chat to work out pressure ratios etc.
Have a word with them, they KNOW what theyre on about.Hope this helps a little.
Tell them what power output you wish to reach(be reasonable..
), boost pressure max you'd like. You may need to work out the flow rate of the engine at full chat to work out pressure ratios etc.
Have a word with them, they KNOW what theyre on about.Hope this helps a little.
Cheers Delta. Why did I Know youd reply lol. Im actually gona have to pay for some profeshional advice arnt I? AR$E! I was just hoping I could buy 2 identical turbos that would suit a 1.75 engine (half 3.5) and fit them. I'm not wanting specific power outputs etc. Just want it to chuck out more power than the standard item.
Cheers anyhow Delta.
P.S. by the end of this i may have 4x 265/75r16 tyres for a gatso pyre.
Cheers anyhow Delta.
P.S. by the end of this i may have 4x 265/75r16 tyres for a gatso pyre.
Best way to find the CR is to measure the combustion chamber volume, with a laboratory pipette, then with the aid of a piece of glass (with a small hole / slot at the chamber circumferance) you then seal this to the head with grease, fill the chamber with water, measure what you've put in and robert should be your mothers brother.
Matt
Matt
350matt said:
Best way to find the CR is to measure the combustion chamber volume, with a laboratory pipette, then with the aid of a piece of glass (with a small hole / slot at the chamber circumferance) you then seal this to the head with grease, fill the chamber with water, measure what you've put in and robert should be your mothers brother.
Matt
Aye, but if you have dished pistons (or they have valve pockets) you have to calculate that volume as well, since it does in effect constitute part of the combustion chamber! I use paraffin for chamber measurement so there's no risk of introducing corrosion to the valves or seats...
Ian
Was it running on methanol, or perhaps diesel?
Highest CR I can find reference to on a standard 3.5 is 10.5:1. This would be a Rover P5/ P6 unit on carbs though I've no doubt that tuners fiddled to get them that high on later versions.
More usually 8.13:1 or 8.5:1. The likes of the TVR 350 were 9.75:1. Some Discovery's ran 9.35:1.
13.5:1 sounds horrendous, even if it were feasible ;-)
Any help?
Ian
More usually 8.13:1 or 8.5:1. The likes of the TVR 350 were 9.75:1. Some Discovery's ran 9.35:1.
13.5:1 sounds horrendous, even if it were feasible ;-)
Any help?
Ian
The engine is from a RaRo.
Just found this one..
"hi chris,the engine is a 3.5 efi 9.35:1 compression ratio,complete with loom ecu,air flow meter" Alls I want to know is if I can change the compression. I must be able to by replacing pistons. Surely?
>> Edited by All Terrain on Tuesday 22 July 06:53
Just found this one..
"hi chris,the engine is a 3.5 efi 9.35:1 compression ratio,complete with loom ecu,air flow meter" Alls I want to know is if I can change the compression. I must be able to by replacing pistons. Surely?
>> Edited by All Terrain on Tuesday 22 July 06:53
danny hoffman said:
You can get thicker head gaskets to reduce the compression
Thicker head gaksets aren't a great way to reduce CR for turbo applications. It reduces (or even negates) the effect of any squish designed into the piston/combustion chamber, something that plays an important part in avoiding detonation.
The CR can be changed by using pistons with a bigger dish (best) or lower compression height (same problem with squish). Alternatively the combustions chamers cab be ground out to get a larger volume.
Chris, I agree completly with Mike. Don't use thicker head gaskets. It's not the way to go at all. As for checking your compression, look on the engine block where the number is, by the dipstick should be the c/r stamped into the alloy. As long as your engine has the original heads the c/r will be pretty accurate. So you should be looking for an export engine on appx 8.5:1 c/r. If you don't get one of those then you could buy export pistons from Rimmers or you could find some buick 300 alloy heads from the US and fit those. If you change pistons then you have to rebalance the engine etc which is why it makes sense to use low boost on 9.35:1 c/r or buy an export lump (they can be quite cheap as nobody here wants them). Buick heads 1963/4 have 54cc combustion chambers and drop the ratio appx 2 ratio's. They also have very big inlets. They always need some refurbishing though.
You can fit t3's to janspeed manifolds if you want to via a spacer plate.
You can fit t3's to janspeed manifolds if you want to via a spacer plate.
boosted ls1 said:
Chris, I agree completly with Mike. Don't use thicker head gaskets. It's not the way to go at all. As for checking your compression, look on the engine block where the number is, by the dipstick should be the c/r stamped into the alloy. As long as your engine has the original heads the c/r will be pretty accurate. So you should be looking for an export engine on appx 8.5:1 c/r. If you don't get one of those then you could buy export pistons from Rimmers or you could find some buick 300 alloy heads from the US and fit those. If you change pistons then you have to rebalance the engine etc which is why it makes sense to use low boost on 9.35:1 c/r or buy an export lump (they can be quite cheap as nobody here wants them). Buick heads 1963/4 have 54cc combustion chambers and drop the ratio appx 2 ratio's. They also have very big inlets. They always need some refurbishing though.
You can fit t3's to janspeed manifolds if you want to via a spacer plate.
Yup I know about the adaptor for the t3 mate. I think im after new pistons anyhow. I would Ideally like to completely rebuild the engine purley as an experience thing. There is a 3.5 EFI from a rangie thats for sale for £300. I dont think the milage matters too much as i expect to relace a lot of parts anyhow. Any more views on the situation?
Yup but my projct is to use the smaller engine. lol Mad I know. And finding engines is an arse. Think ive sourced a 3.5 in an old RaRo. Will cost me £250 for the RaRo withou MOT. As bizarre as it sounds im trying to keep it cheap but not comprimising by not buying certain parts if you get my drift. Also For insurance purposes I believe it has to be a 3.5. (Don't know why??) I could easily Plonk in a 6ltr TDI Froma samurai or similar. bit the challange is to use an old V8 thats smaller capacity and get a fair amount of power out of it. the TDI chucks out 110bhp iirc so anything significantly over thats is great.
Sory if its confusing
Sory if its confusing
All Terrain said:
They are to take rotomaster T04Bs. But as these seem to be hard to track down...
I expect that the Kit is Janspeed (same as mine) and some parts are available, this is what I got back from Janspeed (the MD no less!)
---------------------------------------------------
Good morning,
There are some parts still available mainly exhaust components, however we do not have any turbo's, you can get this part supplied or serviced from BTN Turbo 01895 466666, hope this helps.
Mark Vaughan
Managing Director
for Janspeed Performance Exhaust Systems Limited
Tel: +44 (0) 1722 321833
Fax: +44 (0) 1722 412308
Mobile: +44 (0) 7788 148539
HYPERLINK "www.janspeed.com"www.janspeed.com
-------------------------------------------------
If you want any photos of mine email me and i will send
R
>> Edited by rogue trooper on Friday 25th July 10:55
Easiest way to measure the volume of the combustion chambers is to use plasticine/modelling clay pressed into the chamber(valves in place and seated, plugs blanked) and then level it with a straight edge. remove the modelling clay and drop it into a calibrated measuring jar/beaker with ml graduations, filled to a known level. The extra volume will cause a rise in the level which can simply be read off. No mess, no fuss, thats if you have the head off it already. 
Dont forget to include the gasket thickness as well. If the cr is kept to about the 9.0:1 mark, youll be able to run about 6 psi boost, and wont need an intercooler either.
Based on some very quick and dirty maths, your projected output should be around 370 bhp.
>> Edited by deltaf on Friday 25th July 12:36
Dont forget to include the gasket thickness as well. If the cr is kept to about the 9.0:1 mark, youll be able to run about 6 psi boost, and wont need an intercooler either. Based on some very quick and dirty maths, your projected output should be around 370 bhp.
>> Edited by deltaf on Friday 25th July 12:36
Unfortunatly www.rover-v8.co.uk dont work any more as if it did you just type the engine number in and the Year inc the C/R was quoted 
Of course this works as long as no one has messed with it
R
Of course this works as long as no one has messed with it
R
Gassing Station | Engines & Drivetrain | Top of Page | What's New | My Stuff