3.7 Speed Six Engine Designed and Engineered by RND

[donski58]

I drove my T 350 back from Devon today as the rebuild and re map is now complete. Despite the horrible wet weather and poor visibility which my car would never normally be seen in, I managed to keep a broad smile on my face. The engine is incredibly responsive and refined a totally different beast in comparison to the MBE. I will post some more details and spec tomorrow.

Don

[ShiDevil]

Good Glad to hear a positive experience for you, and lets hope more of the same. I'm open minded about RND, as every business has issues, just look at TVR themselves and to be honest, any form of competition is a good thing. The current status quo, could do with being shaken up a little, as there is no reason to reduce costs for a rebuild, with only 3 providers realistically out there and the only way that will happen is with new entrants, which is never a bad thing.

Are you intending to RR it once it has been bedded in?

[coco79]

Keen to see the results!

[donski58]

Here is the spec and some of the other upgrades that have been completed.

Fully ported and gas flowed stage 3 Head, GT valve springs, GTS Kent cams profiled from blanks, GT cam followers with 360 degree oiling. Extra oil feed to the rear of head on exhaust side.

Block re-bored to 3.7 litre and refaced, Ross racing pistons, New upgraded timing chains,
Crank lightened knife edged and race balanced, 360 degree oiling on the mains. H beam rods lightened and race balanced. New heavy duty race spec main bearings, four bolt main cap conversion.

Omex 710 plus new loom fitted and live mapped.

Bespoke stainless steel exhaust system with re shaped anti reverse spike collector. Upgraded new stainless steel headers which have been stove enameled.

2 upgraded fuel pumps in the tank and an adjustable fuel regulator fitted to fuel rail.

Unfortunately we suffered a speed sensor defect on the rolling road when we were doing the final power run which prevented us recording any data above 5000 RPM. The figures obtained are very exciting: 308 BHP and 325 lbFt at 5000 RPM I look forward to completing a full power run.

Edited by donski58 on Thursday 13th March 20:48

[DAVEY DEE]

Fantastic news Don.Long may it continue.

[donski58]

[donski58]

[donski58]

[JonRB]

donski58 said:

Omex 710 plus new loom fitted and live mapped.

Could I ask what prompted you to go for Omex over Syvecs? Was there some perceived technical benefit or was it cost-based (I have no idea how much Omex costs compared to Syvecs).

[donski58]

DAVEY DEE said:

Fantastic news Don.Long may it continue.

Hi Davey I hope you are well pal?

Don

[donski58]

JonRB said:

Could I ask what prompted you to go for Omex over Syvecs? Was there some perceived technical benefit or was it cost-based (I have no idea how much Omex costs compared to Syvecs).

Hi Jon I was assured that Omex was a really good system which is very easy to Map and has been well proven in some TVR Challenge race cars.

Don

[donski58]

Sorry I have been having snags uploading the pictures I guess they are all around 2 MB which is the maximum download limit.

Don

[macdeb]

Cool car and cool build idea but, can I ask the difference between balance and 'race' balance?

[JonRB]

donski58 said:

Hi Jon I was assured that Omex was a really good system which is very easy to Map and has been well proven in some TVR Challenge race cars.

It is. But Syvecs has knock sensors and multiple maps, plus traction control. Still, no matter; is done now.

I was just interested in knowing what your decision making process was, but it sounds like you went with the recommendation of your engine builder.

[spitfire4v8]

I've mapped a few Challenge cars for 7 years now and yet to see one fitted with an omex. Who gave you that info? MBE, Emerald and Motec are the main players in the race cars..

[dpd3047]

Race balancing means the components match rods are all the same weight no + or - the crankshaft is balanced to zero, the S6 cranks are terrible some are as far out 28 grams, the Knife Edge And lightening allowes the engine to accelerate quicker and less stress and more smoother.
In answer to the Omex, It does have Knock sensor also it can run seqential injection, we are running semi sequential and you can have launch and traction control and it half the price of the Syvecs.

Edited by dpd3047 on Friday 17th January 12:33

[macdeb]

dpd3047 said:

Race balancing means the components match rods are all the same weight no + or - the crankshaft is balanced to zero,

Edited by dpd3047 on Friday 17th January 12:33

Thanks but that is what I'd expect from a normal 'proper' balance [which is what mine is having done], the whole reciprocating assembley; pulleys,trigger wheel,damper,crank,flywheel,clutch pressure plate,rods and pistons. Still hasn't explained what is 'race' balancing? Or is it just a word put in front to make it sound 'racier' when talked of? Not picking a fight, just want to understand
[love the car, I had one once and wish I still did. Is it reflex green/purple, mine was]

Edited by macdeb on Friday 17th January 15:36

Edited by macdeb on Friday 17th January 15:37

[dpd3047]

No its not a word it attension to detail, factory balance can be + or - 4 grams on the rods and pistons, crankshafts are as stated thats why theres a damper on the front to cut down on the harmonics a standard balance as in after market performance parts you will find they are within 1 to 2 grams of each other.I use Andy at Basset Down Balancing and thats what he does.

[JonRB]

Ok, so what you're saying is that 'race' balancing is balancing to finer tolerances than might be expected of 'road' balancing?

How much of a quantifiable difference would this make for a road car?

(Like macdeb, I'm not being belligerent; just wanting to understand and learn)

[dpd3047]

At higher rpm thats when you notice the difference it smoother revs freer, and its less likely to go bang,
and thers no harshness.