V6 to V8 Conversion advice please
Discussion
After much deliberation I’ve decided I‘m converting my V6 S2 to V8 Power, I know it seems a lot of work but I have the engine, box and all fuel /ignition systems as I have had the engine in an MGB and I have a spare chassis to modify as required.
What I want to know is,
1.What Mods would anyone recommend (if any) to the chassis.
2.How will it affect the ECU if I make the ignition and Fuel injection components redundant.Ie will it affect any other components
3. Will a V8s Bonnet fit straight onto an S2
4. Has anyone done this already
5. Are there any mods to the transmission tunnel opening (if anyone has any pics it would be very helpful)
I am planning to start the work on the chassis during this winter and maybe do the conversion over winter 2009 or 2010 depending on how the car gets through its MOTs, I am in no rush whatsoever so any help or thoughts would be greatly appreciated.
Some of the reasons I want to convert is that I like the dash etc on the S2, I have the spare chassis, I have the engine and LT77 box (will that fit) / Fuel and ignition systems for the V8 and I reckon I can do the conversion much cheaper than buying a V8 model.
PS, I will be using a carburettor not Fuel Injection ( I know it’s a step backwards but I like it and I already have it)
Thanks in advance
Ken
What I want to know is,
1.What Mods would anyone recommend (if any) to the chassis.
2.How will it affect the ECU if I make the ignition and Fuel injection components redundant.Ie will it affect any other components
3. Will a V8s Bonnet fit straight onto an S2
4. Has anyone done this already
5. Are there any mods to the transmission tunnel opening (if anyone has any pics it would be very helpful)
I am planning to start the work on the chassis during this winter and maybe do the conversion over winter 2009 or 2010 depending on how the car gets through its MOTs, I am in no rush whatsoever so any help or thoughts would be greatly appreciated.
Some of the reasons I want to convert is that I like the dash etc on the S2, I have the spare chassis, I have the engine and LT77 box (will that fit) / Fuel and ignition systems for the V8 and I reckon I can do the conversion much cheaper than buying a V8 model.
PS, I will be using a carburettor not Fuel Injection ( I know it’s a step backwards but I like it and I already have it)
Thanks in advance
Ken
Where's your sense of adventure lads ? I say go for it .. you seem like you've done a bit of spannering before and you've got plenty of time. V8Ss are rare and tend to be quite expensive .. V6Ss are less rare, cheap as chips and yo already have the engine/box anyway. As Richard Hammond says : how hard can it be?
Ken I'll sort out some pictures for you.
I'm pretty sure your bonnet will fit - the hump was for the italian market supercharger.
The front crossmember has to come out to get the engine out - I don't know if it is possible to get it in / out otherwise.
I'm guessing with 8 cylinders its longer than the V6.
It's a pretty simple mod you could do if you're handy with a welder, and I'm sure you are.
Engine mounts are different.
Rear gearbox mount different.
Both to be expected really as it is a rover unit.
Propshaft is flange to flange arrangement, the LT77 has a flange on the output for those not fmailiar with it.
The rear diff mount is also different, I think it was altered for more strength.
Would be worth getting a LSD if you haven't got one.
(The diff is still a ford type - it looks the same as the V6 ones I've seen, though I guess the ratio may be different)
The chassis also has additional cross bracing.
Ken I'll take some measurements of the engine bay width to make sure it is the same as your chassis.
What engine are you going for?
3.5 litre?
If so I'm just thinking it may not give you the big power hike you're hoping for with the 400cc missing and lack of EFI.
Complete injection systems frequently turn up on ebay and go for next to nothing.
Exhaust manifolds are not cheap wherever they turn up.
Steve Cox who organises some of the racing stuff for TVRCC (not sure of the exact events) had a V8S exhaust a while back (but no manifolds).
I was going to have it but it was in surrey and had to be collected.
Go for it I say - there will be a huge amount of interest!
Also speak to Tvrleigh_BBWR on here - he's done it on a V6 wedge I think.
Chris
I'm pretty sure your bonnet will fit - the hump was for the italian market supercharger.
The front crossmember has to come out to get the engine out - I don't know if it is possible to get it in / out otherwise.
I'm guessing with 8 cylinders its longer than the V6.
It's a pretty simple mod you could do if you're handy with a welder, and I'm sure you are.
Engine mounts are different.
Rear gearbox mount different.
Both to be expected really as it is a rover unit.
Propshaft is flange to flange arrangement, the LT77 has a flange on the output for those not fmailiar with it.
The rear diff mount is also different, I think it was altered for more strength.
Would be worth getting a LSD if you haven't got one.
(The diff is still a ford type - it looks the same as the V6 ones I've seen, though I guess the ratio may be different)
The chassis also has additional cross bracing.
Ken I'll take some measurements of the engine bay width to make sure it is the same as your chassis.
What engine are you going for?
3.5 litre?
If so I'm just thinking it may not give you the big power hike you're hoping for with the 400cc missing and lack of EFI.
Complete injection systems frequently turn up on ebay and go for next to nothing.
Exhaust manifolds are not cheap wherever they turn up.
Steve Cox who organises some of the racing stuff for TVRCC (not sure of the exact events) had a V8S exhaust a while back (but no manifolds).
I was going to have it but it was in surrey and had to be collected.
Go for it I say - there will be a huge amount of interest!
Also speak to Tvrleigh_BBWR on here - he's done it on a V6 wedge I think.
Chris
Edited by Barkychoc on Monday 28th July 11:58
Edited by Barkychoc on Monday 28th July 19:25
trackcar said:
Where's your sense of adventure lads ? I say go for it .. you seem like you've done a bit of spannering before and you've got plenty of time. V8Ss are rare and tend to be quite expensive .. V6Ss are less rare, cheap as chips and yo already have the engine/box anyway. As Richard Hammond says : how hard can it be?
Im with Joolz on this one.He's got the bits he has the ability just needs a bit of help
I converted my S1 to a 4.6 v8 took me a while but well worth it!! I've owened my car from new so want to stick with it. Standard bonnet fits fine I run mine with a 500 webber but have a set quad set off 40 webbers to fit this winter Standard rads fine but do have a big twin fan setup I cut into the foot wells so a bit more room for exhaust manifolds My profile pic may help but will dig out some more a post them
V8_Simon said:
I run mine with a 500 webber but have a set quad set off 40 webbers to fit this winter Standard rads fine but do have a big twin fan setup I cut into the foot wells so a bit more room for exhaust manifolds My profile pic may help but will dig out some more a post them
I was running the MG with the 500 Webber and twin fans, did you cut the footwells out of necessity? and why did you use the alloy plate below the manifolds? Ken I can't remember where I read it but I'm pretty sure the footwells are narrower inside the car on the V8S to accomodate the exhaust manifolds.
The engine sits very far back almost touching the bulkhead - its an unbelievably tight fit.
The best way to accomodate the engine/gearbox I'm guessing would be to suspend it from an engine crane in the chassis then to plan the engine mounts & welding to fit.
I'll take some chassis pics at the weekend and email them to you.
Chris
The engine sits very far back almost touching the bulkhead - its an unbelievably tight fit.
The best way to accomodate the engine/gearbox I'm guessing would be to suspend it from an engine crane in the chassis then to plan the engine mounts & welding to fit.
I'll take some chassis pics at the weekend and email them to you.
Chris
Barkychoc said:
Ken I can't remember where I read it but I'm pretty sure the footwells are narrower inside the car on the V8S to accomodate the exhaust manifolds.
The engine sits very far back almost touching the bulkhead - its an unbelievably tight fit.
The best way to accomodate the engine/gearbox I'm guessing would be to suspend it from an engine crane in the chassis then to plan the engine mounts & welding to fit.
I'll take some chassis pics at the weekend and email them to you.
Chris
Thanks Chris.The engine sits very far back almost touching the bulkhead - its an unbelievably tight fit.
The best way to accomodate the engine/gearbox I'm guessing would be to suspend it from an engine crane in the chassis then to plan the engine mounts & welding to fit.
I'll take some chassis pics at the weekend and email them to you.
Chris
Does the V8 have other enhancements - brakes? suspension?
Always good to see an interesting project, but it's not one I'd personally go for given the availability of V8Ss (yes, I know I'm missing the point!) If you want to do it, why not go for something really different - Chevy LS1 perhaps?
Always good to see an interesting project, but it's not one I'd personally go for given the availability of V8Ss (yes, I know I'm missing the point!) If you want to do it, why not go for something really different - Chevy LS1 perhaps?
Rear brakes are discs - readily available ford sierra items, non vented discs 273 mm diameter I think but don't quote me on that.
You may well need to change the master cylinder to suit.
Wider track on V8S but I think you'd get away with S2 track.
My thinking would be V8S too - there was one kicking about on ebay / PH a while back for £6k - could be worth a wild offer.
You may well need to change the master cylinder to suit.
Wider track on V8S but I think you'd get away with S2 track.
My thinking would be V8S too - there was one kicking about on ebay / PH a while back for £6k - could be worth a wild offer.
hi guys im a newbee to piston heads, i just been on a track day at cadwell park in my tvr s1, i have plans for a v8 conversion on mine over the winter time. the question i have is the s1, s2, s3 chassis the same, would be great for you expert advice and keep the info going. thanks john
John
I am currently going through the process of fitting my S2 body onto a replacement S3 chassis. The main difference is that the rear upright posts which take the top of the shocks are longer and are slightly more inclined on the S3. I understand that these changes reduce the effect of the front wheels getting light under hard acceleration and diving on heavy braking. To accomodate this change the S3 rear trailing arms differ in that the bottom shock pivot point is moved back a couple of inches. Also the later S3 trailing arms are in 2 pieces to allow shimming for toe-in. The rear body mounting bracket on the S3 is higher than the S2 rear mounting bracket, it seems this modification may have been done to allow the easy removal of the trailing arm pivot bolt. The bible (Steve Heaths book)mentions the S3 chassis being modified to take the longer doors but the only change I can find in this reagrd is a couple of bolt fixing points to the top of the S3 chassis each side of the transmission tunnel (under the dash), I recon these may have been added to increase rigidity because of the bigger doors and reduce skuttle shake. I dont really know how an S1 to S2 chassis differs but as a lot of the S1's became S1.5 then S2's without a clear cut off I would therefore imagine the chassis are the same, but somebody more informed will probably confirm this.
Good luck
I am currently going through the process of fitting my S2 body onto a replacement S3 chassis. The main difference is that the rear upright posts which take the top of the shocks are longer and are slightly more inclined on the S3. I understand that these changes reduce the effect of the front wheels getting light under hard acceleration and diving on heavy braking. To accomodate this change the S3 rear trailing arms differ in that the bottom shock pivot point is moved back a couple of inches. Also the later S3 trailing arms are in 2 pieces to allow shimming for toe-in. The rear body mounting bracket on the S3 is higher than the S2 rear mounting bracket, it seems this modification may have been done to allow the easy removal of the trailing arm pivot bolt. The bible (Steve Heaths book)mentions the S3 chassis being modified to take the longer doors but the only change I can find in this reagrd is a couple of bolt fixing points to the top of the S3 chassis each side of the transmission tunnel (under the dash), I recon these may have been added to increase rigidity because of the bigger doors and reduce skuttle shake. I dont really know how an S1 to S2 chassis differs but as a lot of the S1's became S1.5 then S2's without a clear cut off I would therefore imagine the chassis are the same, but somebody more informed will probably confirm this.
Good luck
Edited by TonupS2 on Wednesday 30th July 21:56
Orophin said:
Good grief, and everyone said that buying a V8S would be more bhp/pound than getting a 24v v6 done on my S3. Now this has got me thinking again 
There are a lot of changes on a V8S that you won't get on an S upgrade.The chassis is significantly stiffer for a start, the track of the car is wider too (different wishbones & trailing arms).
If you're happy to have a slightly compromised V8S then do it - I know its not about secondhand value but a converted V6 is never going to be worth the same as a V8.
Edited by Barkychoc on Wednesday 30th July 22:30
Barkychoc said:
Orophin said:
Good grief, and everyone said that buying a V8S would be more bhp/pound than getting a 24v v6 done on my S3. Now this has got me thinking again
There are a lot of changes on a V8S that you won't get on an S upgrade.The chassis is significantly stiffer for a start, the track of the car is wider too (different wishbones & trailing arms).
If you're happy to have a slightly compromised V8S then do it - I know its not about secondhand value but a converted V6 is never going to be worth the same as a V8.
Edited by Barkychoc on Wednesday 30th July 22:30
So you may as well get a V8S. Unless you want to put a different engine in than a rover V8, LS1?. Personally I'd be more inclined to either go fro 24v or a supercharger. Gassing Station | S Series | Top of Page | What's New | My Stuff