Rallye Head

[allye 530 3 Cars]

I'v nearly got the brakes and suspension where I want on my Rallye so thought I would attempt to extract a little power from the engine. Its an iron block originally from a 1992 SPI (supposed to be 35,000 miles) With the standard head and Z2 solex. My mate had got a vtr head (silver top) with a cat cam hidden inside, I know these fit onto my engine but will I have compression issues?

 

Also fairly right in saying the inlet stud pattern is different but the exhaust is the same. So can I make an adapter for the solex onto vtr head? drill tap new holes?

 

Whould it be easier to source a XS head? I was going port/polish maybe gas flow while I was there, which would you suggest?

 

Thanks a lot, Ali

 

(To be honest i can't be arsed with changing the engine to an alloy lump!)

[EdCherry 34 1 Cars]

Dont think you'll have compression issues, but you might have piston/valve clearance issues.

 

Pretty sure I read over on the RR you can drill and tap a hole to fit the smaller model engine inlets onto the larger ones (or was this 8v engines on to 16v?)

 

Then I guess it depends what money you want to spend, bang for your buck im pretty sure carbs would be up there with the best things to do.

[allye 530 3 Cars]

Just changing from my 8v head to a vtr 8v head. Would the dizzy part all fit ok? I have found a 285 cam for my head on here so could just get that and port/polish for some more hp's!

[drmo 5]

This has been covered before. Using big valve head (vtr, 106 rallye, xsi,...) is going to bring CR too low, arround 8,5:1 as I calculated a while ago. The pistons do not top the block which is why they fited domed pistons to 1.4 xsi engine, which also has a big valve head. The combustion chamber on the small valve heads is arround 28cc and the big valve is arround 32,5cc. A huge difference.

Making adapters to fit a xs or similar inlet is a major hastle too, becose the angle on the head is the oposite of that on the small valve heads.

 

The easiest way is to modify your current head and inlet or fit a double solex from ax gt/205 gt/xs. Put a nice cam in and rejet the carb. That is my opinion.

[allye 530 3 Cars]

This has been covered before. Using big valve head (vtr, 106 rallye, xsi,...) is going to bring CR too low, arround 8,5:1 as I calculated a while ago. The pistons do not top the block which is why they fited domed pistons to 1.4 xsi engine, which also has a big valve head. The combustion chamber on the small valve heads is arround 28cc and the big valve is arround 32,5cc. A huge difference.

Making adapters to fit a xs or similar inlet is a major hastle too, becose the angle on the head is the oposite of that on the small valve heads.

 

The easiest way is to modify your current head and inlet or fit a double solex from ax gt/205 gt/xs. Put a nice cam in and rejet the carb. That is my opinion.

 

Sort of what I thought. Does the xs have the same size valves and a different cam? or are the valves bigger Than mine? Like I said I may do some head work on mine also drill the jet out a small amount, 5-10hp from the cam and jet maybe, enough for now!

Thanks, Ali

[burr_2000 1]

Xs is not a bigger valved head. The cam was slightly wilder in a xs.

[trogboy 17]

I have an unused TU3S head and cam, and also a at least a couple of used Z2 solex carbs kicking about if you are interested.

 

The head and cam came from a K2A (TU3S) engine that was bought in error a while back by a citroen dealer and couldn't be returned. The head is complete with valves and springs etc but I have used the rockers and the bottom end for my own engine.

[allye 530 3 Cars]

Theres nothing wrong with me head to be honest, also I rebuilt the carb only 6months so that running ok. What duration is an xs cam? I have found a 285 cam for £70.

 

Cheers, Ali

[swordfish210 20]

Theres nothing wrong with me head to be honest, also I rebuilt the carb only 6months so that running ok. What duration is an xs cam? I have found a 285 cam for £70.

 

Cheers, Ali

 

I think i remember reading that it's around the 255 mark. Make sure the cam is in good condtion, £70 would be a bargain for a good one.

[allye 530 3 Cars]

I think i remember reading that it's around the 255 mark. Make sure the cam is in good condtion, £70 would be a bargain for a good one.

 

Thanks for that, what do people recomend, port/polish or gas flow? or both!?

 

Ali

[burr_2000 1]

honestly, sorry to sound negative but I would save your money until ready to fit a rallye head and get that worked. your really are very limited with a xs head.

take it from personal experience.

[allye 530 3 Cars]

By Rallye head do you mean TU24 head (I think thats the Euro Rallye engine)

[burr_2000 1]

or 106 rallye/xsi. both a huge improvement.

[allye 530 3 Cars]

If I get an xsi head I need the domed pistons though, I havn't got the time for that sort of re-build, I'm mowing to Wales at the end of January so need to get it done by then!

[burr_2000 1]

if you get any of the above heads you will have compression issues. If you dont have time then dont waste money until ready mate. i currently running the newer silver top 1360 bottom end with flat top pistons and throw it away after each season and source another low milage one on the cheap and just transfer my AX GTI head.