Project 36/400 T350R

Project 36/400 T350R

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Discussion

spitfire4v8

Original Poster:

4,017 posts

188 months

Thursday 10th January 2013
quotequote all
Ok, so some of you will have read the earlier thread where getting hp from the little 3.6 engine was going quite well .. finished at 380bhp from that.
Now .. the class the T350 races in has had a slight downgrading of the bhp/tonne regulations .. so whereas the car was about 60-70bhp short of the class limit now it's only going to be about 35-45bhp short of the class limit. The search is therefore on to find just over 400bhp from the little 3.6 engine to make us on the class limit for once.

The engine is out of the car and stripped. This is an engine that cost 500 pounds and has done a season in the car and countless hours on the dyno under test. The only issue was a head gasket leak around the outside of the block .. nothing was getting into the oil or combustion chambers so we just kept filling it up with water and sending it out again. It did half a season's racing like that!

The first thing of note is that the engine has 5 conrods of one sort and one odd one. Very strange .. must have either been like that from new, or had one rod replaced at its previous rebuild. The engine hasn't gone bang yet so I'm putting them back in just the way they are .. touch wood smile
The second thing of note is that even though the engine has been pushed very hard both on track and on the dyno pushing the numbers there's not a hint of any detonation even on cyl 6 .. all good news so far.
The third thing of note is that the cams and followers are as good as new, even with being revved to close to 8k every time it goes out, or on the dyno. Excellent.

As expected though the bottom end bearings are f**ked. I've yet to strip a SP6 that hasn't got u/s bearings. Admittedly all the engines I've seen have been heavy use engines but every one of them had bearings down to the backing. This engine still had good oil pressure at idle too so a dropping pressure isn't the first thing that will alert you to bearing damage sadly. You'll most likely only find out about it when your engine is being stripped for another reason.

So .. this is a project for the next couple of months on and off. The key ingredients will be a nice refresh (cherry picking a combination of parts from different suppliers), some head or cam work depending on what my cylinder head expert thinks is best value, some changes to the exhaust manifolds and exhaust system under the car, and a short inlet airbox.

It's not a massive jump from 380bhp to just over 400bhp so fingers crossed it all goes well.

RedSpike66

2,341 posts

219 months

Thursday 10th January 2013
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Joolz, are you proposing to photo and document it all for us stage by stage ??? biggrin

Ant.

5,254 posts

288 months

Thursday 10th January 2013
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Of course, this will be very interesting..


Joolz, would you say , what you plan would be a "race only" engine or do you expect it to have reasonable road manners?

Podie

46,645 posts

282 months

Thursday 10th January 2013
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Bookmarked smile

donski58

343 posts

165 months

Thursday 10th January 2013
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Keep up the good work Joolz I look forward to the pics I am especially keen on the new Air Box

Don

BCA

8,651 posts

264 months

Thursday 10th January 2013
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thumbup

Glad this project is back on! I'd love to get our 3.6 to 400 still. smile

s5tvr

1,239 posts

240 months

Friday 11th January 2013
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BCA said:
thumbup

Glad this project is back on! I'd love to get our 3.6 to 400 still. smile
Agreed. If Porsche can get 400+ bhp out of their N/A 3.6 then you'd think someone could do the same with the SP6 ?

RedSpike66

2,341 posts

219 months

Friday 11th January 2013
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Now don't all jump on my case and abuse me, but wasn't the original Melling design a 3.5/3.6 that was good for a genuine 380/400bhp (if it didn't break), and that's what RND engineering reckon the 3.6 can produce rebuilt correctly, with their re-profiled cam and finger followers ??

Hopefully Joolz can achieve that, as he's already made great progress and done a super job with CliveF's Sag - 414bhp

Joolz - when can we expect the launch of the products/services to get the 4.0L tuning package - new airbox, modified throttle bodies, cam, cam timing etc that worked so well with CliveF's exhaust mods ??

bionicjim

473 posts

146 months

Friday 11th January 2013
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Hi josh
How's you doing
This is jim that crazy b-----erd with the blue cerb

spitfire4v8

Original Poster:

4,017 posts

188 months

Friday 11th January 2013
quotequote all
airboxes are way behind schedule so clivef is making me one for the race car identical to the one on his sag which seems to work smile My friend is a leading light in the world of straight 6 engines so i'll be leaving the way forward on head/cams to him based on his flowbench findings.

Don1

16,065 posts

215 months

Friday 11th January 2013
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The extra air in and out of the S6 does seem to be the way forward.

dpd3047

250 posts

173 months

Friday 11th January 2013
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RedSpike66 said:
Now don't all jump on my case and abuse me, but wasn't the original Melling design a 3.5/3.6 that was good for a genuine 380/400bhp (if it didn't break), and that's what RND engineering reckon the 3.6 can produce rebuilt correctly, with their re-profiled cam and finger followers ??

Hopefully Joolz can achieve that, as he's already made great progress and done a super job with CliveF's Sag - 414bhp

Joolz - when can we expect the launch of the products/services to get the 4.0L tuning package - new airbox, modified throttle bodies, cam, cam timing etc that worked so well with CliveF's exhaust mods ??
Hi Redspike, Mellings engine was 80.5 mm stroke x 96mm bore 3498 cc the key is the cams and followers as you said .
Ive got the original profile the engine made 402 BHP at 7500 rpm and no it didnt blow up! did you read the feature in sprint mag, Clives Cams are mine and also the cam timing i gave to Clive to set them up. Dave RND ENG

donski58

343 posts

165 months

Friday 11th January 2013
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Hi Dave I think I will have a closer look at your cams etc to see if the 3.6 can really push out over 400 bhp. I cant wait Yahoooo!!!

RedSpike66

2,341 posts

219 months

Friday 11th January 2013
quotequote all
dpd3047 said:
RedSpike66 said:
Now don't all jump on my case and abuse me, but wasn't the original Melling design a 3.5/3.6 that was good for a genuine 380/400bhp (if it didn't break), and that's what RND engineering reckon the 3.6 can produce rebuilt correctly, with their re-profiled cam and finger followers ??

Hopefully Joolz can achieve that, as he's already made great progress and done a super job with CliveF's Sag - 414bhp

Joolz - when can we expect the launch of the products/services to get the 4.0L tuning package - new airbox, modified throttle bodies, cam, cam timing etc that worked so well with CliveF's exhaust mods ??
Hi Redspike, Mellings engine was 80.5 mm stroke x 96mm bore 3498 cc the key is the cams and followers as you said .
Ive got the original profile the engine made 402 BHP at 7500 rpm and no it didnt blow up! did you read the feature in sprint mag, Clives Cams are mine and also the cam timing i gave to Clive to set them up. Dave RND ENG
Hi DPD,

Yeah I thought the Sprint article was really really interesting, and I've since read every paragraph on your webpages too - again, interesting stuff and bookmarked for the future engine build (there will be one !!). Great results with CliveF's engine.

It was TVR that said Al's engine's didn't last 15mins - not me by the way.

Really looking forward to seeing power/torque graphs of your engine builds - don;t be shy - make sure you publish what your engine's achieve !!

Tell me, does the engine have to come out to change the cams and the timing ??

Regards


dpd3047

250 posts

173 months

Saturday 12th January 2013
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No it does`nt have to come out, take the cam cover off make shore the engine is at TDC slacken the tensioner so the chains are loose undo the sprocket bolts, careful not to drop them down the timing chain cover pull the chains away and tie them up so the sprockets are free undo the cam caps evenly front to back mark the caps they might be already marked once undone lift the cams out if your changing the followers thats a different matter hope this helps DPD.

Edited by dpd3047 on Saturday 12th January 00:51

Buzz Billsberry

1,306 posts

238 months

Saturday 12th January 2013
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RedSpike66 said:
Hi DPD,

Yeah I thought the Sprint article was really really interesting, and I've since read every paragraph on your webpages too - again, interesting stuff and bookmarked for the future engine build (there will be one !!). Great results with CliveF's engine.

It was TVR that said Al's engine's didn't last 15mins - not me by the way.

Really looking forward to seeing power/torque graphs of your engine builds - don;t be shy - make sure you publish what your engine's achieve !!

Tell me, does the engine have to come out to change the cams and the timing ??

Regards
Mike do you have a link for the web pages?

Thanks

Buzz

alex_gray255

6,316 posts

212 months

Saturday 12th January 2013
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Hi Buzz

RND engineering is http://www.rndengineering.co.uk/

Thanks

DAVEY DEE

647 posts

161 months

Saturday 12th January 2013
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I'll put my figures up for you in March when its run in & remapped.Daves doing my rebuild for me.Used all his kit & shiny bits in it.

TVR_owner

3,349 posts

198 months

Saturday 12th January 2013
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Joolz,
I suspect youre runing in class B Tuscan Challenge?

Why not go for the 4.0 and get the torque thats missing from the 3.6 and the power rather than try and strangle more from the 3.6??

Good luck which ever way you go. smile


spitfire4v8

Original Poster:

4,017 posts

188 months

Saturday 12th January 2013
quotequote all
Hi John .. the little 3.6 has been the most reliable engine we've ever had, no other sp6 engine has lasted a whole season .. so it's a case of better the devil you know smile Plus plenty of other people are pushing bigger capacities and exotic cam control strategies, albeit at a price. I'm interested in seeing what the 3.6 can do as much as a technical excercise as anything. There's little point in me competing directly against the likes of tvr power and racing green, I just can't afford the time and money those guys pour into their r and d. So there's many reasons for sticking with the 3.6, it's been a cracking little engine for us so far. touch wood smile