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Doing a little research

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A couple of other points 4U - as you know the diff is going to be marginal at (say) 200hp. You might want to consider strengthening the mounts when you pull it if you do the LSD. I put (or actually paid to have put) a ton of extra metal in there.

Also think about con-rods if you start an upgrade for that sort of power (and nitriding/cryoing the crank and and and).

A couple of alternative suggestions I'd offer would be to consider either a supercharger conversion or go to tbi.

Both are going to be around the price of the PRI offering, and offer some flexibility for extra oomph.

You could even (if you are feeling adventurous) combine the two, but you'll have some work to do on the fuel delivery system. You do have the potential for really big power then, while still keeping a "stock" TR6 engine.

I'm not trying to talk you out of carbs by any means - I meant it when I said I wanted to see dyno #s for them, I'm just trying to give you a couple of other considerations.
 
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A couple of other points 4U - as you know the diff is going to be marginal at (say) 200hp. You might want to consider strengthening the mounts when you pull it if you do the LSD. I put (or actually paid to have put) a ton of extra metal in there.

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Agreed - I think that boxing in the diff mounts is something that should be done regardless - just like strengthening the front suspension mounts

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Also think about con-rods if you start an upgrade for that sort of power (and nitriding/cryoing the crank and and and).

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Very true, not to mention another 'must fix' in my opinion - thrust washer modification. The fix I think I'd use in the TR motor is a combination: Scott Helm's alloy washers along with a groove cut in the main bearing cap to accomodate a second thrust washer.

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A couple of alternative suggestions I'd offer would be to consider either a supercharger conversion or go to tbi.

Both are going to be around the price of the PRI offering, and offer some flexibility for extra oomph.

You could even (if you are feeling adventurous) combine the two, but you'll have some work to do on the fuel delivery system. You do have the potential for really big power then, while still keeping a "stock" TR6 engine.

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Whew, we are talking big bucks now! I understand that Moss' supercharger setup for the TR engine is almost ready and it sure looks tempting. I'll even admit to being drawn to Rick Patton's TBI injection system - that's a real sleeper system!

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I'm not trying to talk you out of carbs by any means - I meant it when I said I wanted to see dyno #s for them, I'm just trying to give you a couple of other considerations.

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I know, and there are so many options out there when you start looking at this. You've made many good points, and I appreciate your input

/ubbthreads/images/graemlins/thumbsup.gif
 
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Whew, we are talking big bucks now! I understand that Moss' supercharger setup for the TR engine is almost ready and it sure looks tempting. I'll even admit to being drawn to Rick Patton's TBI injection system - that's a real sleeper system!

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I was actually talking about the Vespertino s/c setup. Draw through 2" SU and an M62 (the old style rather than the newer MP62) that bolts onto the intake manifold. Should come in at less than the 2k for the 6-pack from PRI and be an afternoon to swap back to stock.

I understand Moss went with the same basic design.
 
I hadn't heard of that one - please tell me more /ubbthreads/images/graemlins/confused.gif
 
Thanks, I'll check into it /ubbthreads/images/graemlins/grin.gif
 
A friend sent me a sneak pic of the Moss supercharger setup, attached is a pic of what I think the first test version.
 

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Great pic Randy, thanks for sharing it with us! That sure looks like a nice setup.


BTW, I got a response from the Australian guy who had the Mazda E5 conversion done and he's put me in touch with the shop that did the work. Apparently they sell the pistons and rods as a set (because of the machining required on them) I'll keep everyone updated on what I find out.
 
Update: Still no response from the Australian firm that specializes in the Mazda E5 conversion, but if anyone is interested in contacting them they are Greg Tunstall Mechanical in Queensland and their website is https://users.bigpond.com/GTMech/ If I do hear from them, I'll pass on anything I can find out.
 
Ray,
I checked the Williams book. Alana is correct,, he does not mention the Mazda pistons. I must have combined the concerns about wall thickness for Mazda pistons with Williams' comments about needing to recenter the bores for a large overbore. Both of which need to be taken into consideration.
BOBH
 
Thanks for double-checking for me Bob. I was thinking that I might get around those concerns by sleeving the engine, do you think this would be a good approach? Of course, this is all theory at the moment because I have yet to pick up a TR6 engine - or hear back from the Australian company that supposedly specializes in the conversion.
 
Ray,
I don't have the expertise to say one way or the other. Based on my reading and research on other engines I can tell you that some engines vary from engine to engine on the centerline of their cylinders. The problem is usually attributed to core shift during the casting process. When this happens the centerline of the material is slightly offset from the centerline of the bore. This creates a cylinder wall that can be thinner on one side than on the opposite side. This is where it would be helpful to hear from the fellas down under. They should have a better idea of the consistancy in the TR6 block castings.
Once you get some feedback from them, you can decide if sectioning a spare block will give you an accurate picture of these blocks in general.
An option is to have the block tested to determine the amount of material available for your overbore. I believe the correct method of testing is to use ultra sound. Check with your machine shop.
If I can get some time on the computer tonight I'll see if I can scan the section from Williams' book.
 
Makes sense. I still hope to hear from the boys down under, but in the meanwhile I have found out that PAECO offers a stroker kit that increases displacement from 2496cc to 2773cc and consists of a .060" overbore and an increase in stroke of .250" - which sounds like they may be doing the same thing, but I haven't talked to them directly yet. I don't know anything about the company, does anyone here have any reccomendations?
 
you saw the revington +.110" pistons right?

the problem with all this is that you are still talking relatively modest displacement improvements (about 10%), and the cost seems to be escalating disproportionately. The kit is 2k, then you are looking at machine work. You'll likely need to do the top end at the same time.

OK, with a compression boost and a triple carb setup you ought to be able to pull out decent power, but I still think you'll get more for less effort going to forced induction.

Oh and I remembered this from a few days ago - I know nothing about the place personally, I just downloaded their catalog...

https://www.britishcarforum.com/ubbthread...true#Post200589
 
I did see those, but like you thought the cost outweighed the benefit - which seems to be the case with the Mazda E5 conversion (if that's what Paeco is doing). For that kind of money I could do the supercharger or even get a complete Toy motor and drop it in.

But it's doing this kind of research that allows a person to make an informed, intellegent decision, instead of a gut reaction. You still have to weigh intangibles such as heritage and if you're trying to preserve some form of originality, but having a clear idea what each possible route will cost helps no matter what the final decision is.
 
Hey, don't get the wrong idea here. I'm not knocking you - good luck whatever you choose to do. It's your car, and so its your choice.

It just seemed like a lot of money for relatively little gain. Given the amount I've spent on my TR6 I'm the last person that should be bleating about cost/benefit though, so perhaps I'll just shut up...
 
I didn't take it as you knocking my idea - I was looking for feedback and that's exactly what everyone has given me. I find I spend a lot more time thinking and talking about what I'm going to do then it actually takes me to do it, but that process helps me avoid a lot of bad or poorly-thought-out work. I know the people on this list have probably done or thought about anything I could come up with, so why shouldn't I try to draw on that experience?
 
Re: Doing a little research - Results

Ok, this is what I've been able to glean from the Internet so far:

The Mazda E5 conversion is accomplished by boring the cylinders .110" oversize and using .020" oversize E5 pistons to achieve the 2.7L. The bores are NOT recentered for this conversion, but I've been unable to get an answer as to the how thin cylinder walls are at this point. (no response from the Australian firm that does the conversion) The one person I was able to find that had the conversion done did not report any issues.

I also found out that Paeco does a 2.7L conversion by using the largest oversize piston (.060") and increasing the stroke .250" I'm not sure what effect this increase would have on a engine that is already 'oversquare'.

Since I have not aquired a test TR6 engine yet, I do not see my being able to contribute anything further for the time being.

I want to once again thank everyone for their input, and hope this research project has been useful - or at least entertaining /ubbthreads/images/graemlins/jester.gif
 
Personally I'm a big believer in forced induction. 205 HP at the rear wheels costing less than a set of webers is hard to argue with. More information available at:

www.turbo-tr6.info

Hope this helps
Lee
 
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