Project 36/400 T350R
Discussion
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
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.
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
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.
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 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
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 Small update. Bottom end is built up. Head has had some light porting work. Reprofiled cams are next on the list then the head can go on. Then making up the new exhaust system and fitting the modified throttle bodies. Then into the car. Still a bit to do yet but it's getting there bit by bit.
Hi RS .. there's nothing special about the build at all .. the bottom end and chains is all std with parts from tvr power incl head gasket. The head studs are from racing green. cams are bespoke. rings are total seal gapless top ring set. airbox is from clivef to my short lengths (made in stainless because I need to be able to weld to it for another project of mine). exhausts will be modified with less severe bends in, but i've got a different gearbox mount which allows me more freedom under the gearbox than std cars. head is tidied up in the valve guide/throat area but the rest of the ports are left std, they flow more than the valves already so no point doing anything in the straight bits. so nothing out of the ordinary at all.
Just a (almost) final update on this project. Well 36/400 is a little optimistic right now, but only a little. It's project 36/395 at the moment but the exhaust silencers I've got on there right now are 2.25 inch which means I've had to sleeve the intermediate pipes down from 2.5 inch .. I think with a decent exhaust on it would be 400hp. At the moment though I'm quite happy with 110bhp/litre.
Here's the graphs. The rpm scale is slightly out, the rpm limiter is at 7800rpm rather than 7400 ish that shows on the graph, so the torque is exagerrated, it should be more like 308lb.ft rather than 320.
updated with a better graph
Here's the graphs. The rpm scale is slightly out, the rpm limiter is at 7800rpm rather than 7400 ish that shows on the graph, so the torque is exagerrated, it should be more like 308lb.ft rather than 320.
updated with a better graph
Edited by spitfire4v8 on Wednesday 2nd April 19:00
I'd love to keep going but the power just keeps going up and up the rev range .. need some better bottom end components to really push things to the next level I think. I daren't rev a std engine past 8k. It might be fine for a while, but you just know that sometime it's going to throw something through the side ..
RedSpike66 said:
Can we have a 'summary' of the changes that lead to these super figures (without giving away too much to the competition !!)
Regards
Mike
a good exhaust, flowed intakes, racier cam timing, short induction airbox, a little bit of porting on the head, total seal piston rings and a remap. Regards
Mike
It's been over a year since this thread last saw action, but the T350R was out at Brands last weekend so thought I'd update it with what happened.
The car hadn't run in anger for 3 years, and the tyres were at least 3 years old, possibly older. Cliff also hadn't driven the car except for a poor test day at Oulton last year where we failed the noise tests and had a gearbox seal failure meaning total track time was about 10 mins ..
and so we arrived at Brands with little idea of how the car would go.
In the end the car was great .. class pole and 2 wins (although the competition in the class wasn't exactly overwhelming, just the three cars out in class b sadly ..)
Of note though is the results of looking through the datalogger data .. despite being slower through most corners by around 5mph, the car was faster at the end of the straights by around 3-4mph compared to our last good data from Brands .. so it looks like the build has been well worthwhile.
The car hadn't run in anger for 3 years, and the tyres were at least 3 years old, possibly older. Cliff also hadn't driven the car except for a poor test day at Oulton last year where we failed the noise tests and had a gearbox seal failure meaning total track time was about 10 mins ..
and so we arrived at Brands with little idea of how the car would go.
In the end the car was great .. class pole and 2 wins (although the competition in the class wasn't exactly overwhelming, just the three cars out in class b sadly ..)
Of note though is the results of looking through the datalogger data .. despite being slower through most corners by around 5mph, the car was faster at the end of the straights by around 3-4mph compared to our last good data from Brands .. so it looks like the build has been well worthwhile.
Sadly not .. development stopped when I ran out of time but 400 is just around the corner. The exhaust we have on isn't the best in the world so it wouldn't be hard to get it. Ironically it would be easier on a road car to get 400 .. no track noise regs to have to deal with ..
No Manley race valves or GT cams or unpaid invoices in this engine either ..
No Manley race valves or GT cams or unpaid invoices in this engine either ..
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