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Neil-h

Semi-forged engines

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Hi All,

Has anyone on here got any experience running a semi-forged engine (i.e. forged rods with OEM pistons)? I've been looking at the semi-forged build Fensport offer using Brian Crower rods as the complete drive in drive out package (including oil systems mods) looks like a steal for 4 grand so i'd be interested to hear from anyone that's done this build or indeed anything similar.

https://www.fensport.co.uk/pages/forged-engine-build-prices

Ta,
Neil

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On 9/23/2021 at 8:45 PM, Leeky said:

This is exactly what I am planning to have done if I ever bend a rod. £3.8k for a preemptive rebuild seems very reasonable.

Why would anyone get a fully built engine when all that goes wrong on our cars is the rods anyway ? This sounds too good to be true

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10 hours ago, Jay Bamrah said:

Why would anyone get a fully built engine when all that goes wrong on our cars is the rods anyway ? This sounds too good to be true

It's only the rods that go because they're the weakest part, make them stronger and something else will go 

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If you upgrade the rods you don’t automatically break the next weakest thing. Doesn't work like that. All comes down to what power you are asking of the engine.

280-300 is generally regarded as the reliable stock rod limit. Fensport say their bottom end rebuild is good for “Up to 450bhp” so as long as you aren’t looking for more than 350-400bhp from your engine it should be pretty reliable.

As they explain on their site, there is good reason to upgrade the rods but leave the pistons stock.

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On 9/26/2021 at 5:53 PM, Jay Bamrah said:

So basically if you have 300hp and bend a rod theirs two options. Fully forged 400HP engine 10kish or semi forged 300hp 3.8k ish 

Rebuild to a fully forged 400hp engine was a few quid shy of £15k by Mike at TD (including K Sport Front BBK). Not to mention the other £5k loan per year to buy oil because I go through about a litre every couple days, and have to check it and top it up so often, it's a pain in the arse and I wouldn't recommend it at all

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6 minutes ago, GT86Reece said:

Rebuild to a fully forged 400hp engine was a few quid shy of £15k by Mike at TD (including K Sport Front BBK). Not to mention the other £5k loan per year to buy oil because I go through about a litre every couple days, and have to check it and top it up so often, it's a pain in the arse and I wouldn't recommend it at all

The oil consumption doesn't sound right - have you had it checked out?

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3 hours ago, Deacon said:

The oil consumption doesn't sound right - have you had it checked out?

I know, I've questioned it and questioned it several times, been on-going for months with this usage. I checked it myself at home, no leaks or smoke. I took it to Abbey Motorsport, they also checked it over, no leaks or smoke. I called Mike and he was puzzled and said to try monitoring it with different types of driving, so quite heavy footed for a week then just on cruise for a week for example... same usage. Then he advised to try changing from 5w-40 to 10w-60 as the thicker grade may reduce the usage, or so he thought... still the same. Took it back to TD for investigation and it ended up being there 4 months before I got it back (previously been there 2 times, for 6 months each... first time for engine rebuild / turbo etc and second time for a misfire). Minimal testing was done during this period to my frustration but Mike couldn't find anything wrong with it. Mike fitted an oil restrictor to it but still using the same amount of oil... still getting no smoke, no leaks... and performance remains normal, so I'm baffled by it too!

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30 minutes ago, GT86Reece said:

I know, I've questioned it and questioned it several times, been on-going for months with this usage. I checked it myself at home, no leaks or smoke. I took it to Abbey Motorsport, they also checked it over, no leaks or smoke. I called Mike and he was puzzled and said to try monitoring it with different types of driving, so quite heavy footed for a week then just on cruise for a week for example... same usage. Then he advised to try changing from 5w-40 to 10w-60 as the thicker grade may reduce the usage, or so he thought... still the same. Took it back to TD for investigation and it ended up being there 4 months before I got it back (previously been there 2 times, for 6 months each... first time for engine rebuild / turbo etc and second time for a misfire). Minimal testing was done during this period to my frustration but Mike couldn't find anything wrong with it. Mike fitted an oil restrictor to it but still using the same amount of oil... still getting no smoke, no leaks... and performance remains normal, so I'm baffled by it too!

Bizarre! 

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Assume you are running a lot of boost to get 400bhp so is the crank case getting unduly pressurised to create pullover?

Is the ring pack up to the job? Is it the engine? Is the turbo pulling oil?

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@GT86Reece Thank you for sharing your honest feedback and experience mate! This is what this forum is for. Not be a positive echo chamber but a honest feedback mechanism.

It is unbelievable that you have had the car with TD for 16 mths ( 1 yr +) of its life and that the car drinks oil like petrol.

Scares the life out of me and makes me realise why people stay with big brands for modding.

Sent from my SM-G781B using Tapatalk

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10 hours ago, GT86Reece said:

Rebuild to a fully forged 400hp engine was a few quid shy of £15k by Mike at TD (including K Sport Front BBK). Not to mention the other £5k loan per year to buy oil because I go through about a litre every couple days, and have to check it and top it up so often, it's a pain in the arse and I wouldn't recommend it at all

Did u only get this problem once u got a build engine? So running 290HP was fine? Well unless u went from stock straight to forged engine 

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Sorry all, I'm not too active on the forums!

On 10/12/2021 at 3:43 PM, McDude said:

Assume you are running a lot of boost to get 400bhp so is the crank case getting unduly pressurised to create pullover?

Is the ring pack up to the job? Is it the engine? Is the turbo pulling oil?

I'm running 14psi to get 400bhp and not as far as I'm aware but I don't know too much about engines etc if I'm honest. As far as I'm aware, the engine seems fine and Mike has done all sorts of tests so he tells me but couldn't tell you what those are as I'm not sure either. Turbo isn't appearing to be pulling oil. Car runs absolutely fine, no oil leaks and not smoking at all so it's very odd but also very frustrating!

 

On 10/12/2021 at 10:08 PM, BRZ-123 said:

@GT86Reece Thank you for sharing your honest feedback and experience mate! This is what this forum is for. Not be a positive echo chamber but a honest feedback mechanism.

It is unbelievable that you have had the car with TD for 16 mths ( 1 yr +) of its life and that the car drinks oil like petrol.

Scares the life out of me and makes me realise why people stay with big brands for modding.

Sent from my SM-G781B using Tapatalk
 

No worries, I could write quite a lengthy review on it but it's just getting the time to do it to be honest and would take me a bit of time to gather all of the information as it back dates to when I initially blew it up in September 2019! It is mad that the car has been with TD for a total of 16 months agreed, it's been very frustrating to say the least and of course wasting tax and insurance money whilst it's not been with me... Gutted it drinks so much oil, it's not fun having to check it all of the time and having to top it up so frequently. For example a trip to the Lake District used 800ml of oil to get there and a further 800ml to get back (300 miles each way). So just shy of 3ml per mile... seem to be using more oil than F1 cars or fighter jets...

 

On 10/12/2021 at 10:21 PM, Jay Bamrah said:

Did u only get this problem once u got a build engine? So running 290HP was fine? Well unless u went from stock straight to forged engine 

I wasn't originally running 290bhp, I went from a normal blown NA to full forged & turbo'd 400bhp and it's been problematic ever since in that aspect. Runs fine though, so I try to ignore that it uses so much oil (other than having to check it every day) and try to enjoy it for what it is, as it's pretty fun otherwise...

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If there isn't a puddle of oil on the floor the only places it can go are into the combustion chamber or leaking out the turbo and into the exhaust (and burning there). If it's coming out the turbo I'd expect you to see smoke, which you say you don't see.

What do your exhaust tips look like? This should be creating a fair bit of soot for that much oil even if it doesn't appear as smoke.

As this is a rebuilt engine my guess is the crankcase is getting pressurised and the oil is coming up via the rings and burning in the cylinders. What do your spark plugs look like? They'd be pretty black if this is happening. But you might not see it in smoke coming out the back.

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