Notices

Reply
 
Thread Tools Display Modes
  #11  
Old 06-04-16, 10:00
adamss24 adamss24 is offline
Van Master Jedi
 
Join Date: Jan 2011
Location: london
Posts: 636
Default Re: T4 2.5 tdi race engine build goal 300 bhp+

Also i can see that you cleaned the intake ports a little, there is a lot to be gained if you go in a bit further. I will also fit pd130 blac/DLC coated hydro lifters especially if you choose an aggressive camshaft. Have a look on my engine rebuilt, i have rebuilt mine a few years ago but never enough time to finish it ! I even have a few hybrid gtb2260 vk and vklr's (ball bearing turbos) with titanium billet compressor wheels and larger AMG turbines... If you get stuck then drop the van to me, i will make sur you hit 300 Bhp on half the budget you will spend !
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #12  
Old 06-04-16, 13:20
slimjim's Avatar
slimjim slimjim is offline
Serial Poster
I Support Macmillan
 
Join Date: Aug 2011
Location: Telford, Shropshire
Posts: 4,901
Default Re: T4 2.5 tdi race engine build goal 300 bhp+

Quote:
Originally Posted by adamss24 View Post
Best formula would be stock AXG 150 Bhp with rosten rods, pd150 pistons, factory Twin valve spring setup, Bosio race 520 nozzles, stock pump, gtb2060 vklr or gtb2260 vklr ( if you want less EGT). That will be more than enough for your power goal. Add a decent FMIC and egr delete + a man sized clutch ( use Sachs SRE) and you should have no problem running these. If your budget does not stretch far enough for aftermarket rods then pd115 rods drop in and sre far more robust + have tapered small end to work with the pd pistons ! I have built plenty engines and on most builds the money are wasted on bling parts and not on relevant parts !
I'm confused by a lot of this...

Why would, for example, a factory twin valve spring setup be "best" over say a Rosten performance spring setup?
Same thing for say a stock pump (which was no-where near strong enough for clean atomisation on my setup) be better than a balanced 11-13mm upgraded United Diesel pump...?
Reply With Quote Quick reply to this message
  #13  
Old 06-04-16, 13:25
slimjim's Avatar
slimjim slimjim is offline
Serial Poster
I Support Macmillan
 
Join Date: Aug 2011
Location: Telford, Shropshire
Posts: 4,901
Default Re: T4 2.5 tdi race engine build goal 300 bhp+

Keep going down the route you are 10 stallion.

... and make sure you keep the updates, photos and images coming!

Last edited by slimjim; 06-04-16 at 14:15.
Reply With Quote Quick reply to this message
 
  #14  
Old 06-04-16, 20:41
kwempe kwempe is offline
Van Pro
 
Join Date: Jan 2013
Location: Bedfordshire
Posts: 64
Default Re: T4 2.5 tdi race engine build goal 300 bhp+

I'll start by saying that the person called "Keith" that Stallion10 is referring to is actually me and not the "Keith" referred to by Bongofury....

Now as it is the last and most mentioned thing in the thread, I'll give my personal input on valve springs. Some might disagree but here goes..

The case for stronger valve springs, I believe would become a valid one in three cases:-
1/ Higher than manufacturer designed maximum engine RPM
2/ Very high boost pressures
3/ High lift camshafts or those where longer duration means the valve closing ramp is at a sharper than standard degree

So to elaborate, we do not plan to use higher than 4500rpm as our maximum engine speed and nor do we see the need to use a high lift or longer duration camshaft and for that reason we have decided no to use heavier than/stronger than standard valve springs. The boost pressure we are going to run is considerably less than I believe would require extra strength in the valve springs in order the prevent boost pressure from blowing them open and I believe only a compound turbo engine running circa 100psi of boost would be likely to actually do this. This is especially true because of the huge compression pressure that a diesel engine produces that blows the valves against their seats from the inside of the engine. Next then is the camshaft, there are benefits to be had from performance camshafts but invariably the benefits are experienced higher up the rpm range than a standard engine and this engine is still going to be used as a day to day delivery/work van for its owners own small business. Using a stronger spring will be negative in this respect as the valve train actually uses a considerable amount of power from the engine and to some extent this will tend to nullify the benefits of a performance camshaft but it will also increase fuel consumption. Don't underestimate the power it does actually take to rotate a camshaft, just try doing so with a spanner on a cylinder head that is removed from the engine. The force required is considerable! Next is the wear on the cam itself, higher spring pressure will push the follower against the camshaft with a correspondingly higher force and the cam will wear quicker because of this. I had a tuned Pinto engine back in the 1980's that I had to replace the camshaft yearly and that was a race cam. I did use the best oils available at the time and I had a high flow pump and larger holes on the spray bar too!

Next then is my opinion on double valve springs. On a petrol engine, at high rpm, harmonics become a problem and valve float can occur at very high RPM, for this reason, double valve springs are used. Why are they used? Quite simply because the harmonic frequency for which one strength and size of spring "bounces" at is different than another. If you therefore use two different size and strength springs on a single valve, the harmonic frequency for bounce on one spring will effectively cancel out the bounce frequency of the other and valve float can be avoided. There is a secondary benefit for a high revving engine in that the combined pressure of both springs is stronger and as such a steep closing ramp on the camshaft can be used. This steep closing ramp is required if the duration of the cam has been extended as the valve still has to meet the timing requirements for the combustion cycle of the engine. I had better mention that duration is simply a longer lobe that keeps the valve open for longer. A third benefit is that thinner wire can be used to make double springs to give the same or higher strength of single springs and because the wire is thinner, the valve can compress the spring by a greater distance if a high lift cam is used.

Ok given all that, to summarize, we are sticking with standard valve springs and a standard camshaft because of day to day drive-ability and fuel consumption. Because we are not increasing engine rpm and because the boost pressure required to produce valve float is not within the realms of anything but an exotic turbo setup. We are (hoping!) going to achieve our goal by using a hybrid GT2260v that will run much lower day to day power outputs but will "other options" available to us for the odd drag race.
I have already personally managed to get the standard ecu to run with software normally found in a VNT version of this engine and to use larger injectors/turbo etc as fitted by its owner (10Stallion) and we are now simply building on the success of the work carried out so far. As a daily driver, this build also has cost considerations and as such, any advice I give to the owner has to have cost and reliability as a consideration as well as reliability.
I'd better add that I am an amateur tuner, my day job is a Fireman
Reply With Quote Quick reply to this message
  #15  
Old 06-04-16, 20:42
kwempe kwempe is offline
Van Pro
 
Join Date: Jan 2013
Location: Bedfordshire
Posts: 64
Default Re: T4 2.5 tdi race engine build goal 300 bhp+

Quote:
Originally Posted by slimjim View Post
Keep going down the route you are 10 stallion.

... and make sure you keep the updates, photos and images coming!
Thanks Bongo!
Reply With Quote Quick reply to this message
  #16  
Old 06-04-16, 21:16
kwempe kwempe is offline
Van Pro
 
Join Date: Jan 2013
Location: Bedfordshire
Posts: 64
Default Re: T4 2.5 tdi race engine build goal 300 bhp+

ARL headbolts are widely recognized as being the spherical appendages of a K9 among the TDI forums when tuning 1.9 tdi VE engines and as Adamss24 says, so are PD pistons. The PD engine was and still is way ahead of its time regarding astonishing levels of torque from quite a small capacity engine. Extreme "in cylinder" pressures meant that VW had to apply special consideration to the strength of its internal components. What do I mean by extreme? How about around 4000kgs of force being applied to the piston crown on each combustion cycle, yes four tonnes! Obviously only at full chat This meant using fractured big ends on its conrods, whereby they are actually broken rather than machined and a broken rough surface left on the mating faces so that the friction of the parts is massively increased as to avoid "spread" of the big ends under extreme load. Tapered small ends were also used so that the rod passes its downward load sideways into a corresponding taper in the piston gudgeon pin abutments to reduce load on the surface that acts on the pin itself..

We did consider using PD pistons and rods but cost became prohibitive when other factors were taken into account and having seen Shadowmaker push this engine to much higher limits, we chose to use the standard, unworn, pistons again. Cost would be high because an 81mm bore is used and as such we would need brand new 2.0tdi pistons with the 4 valve head pockets machined off. We also found that the big end part of the conrod was wider and as such would need milling to fit the journal for which it is to run on the crankshaft, this would reduce the benefit of using this rod for this application. Of course we had considered regrinding the crankshaft to increase the journal width too but the amount of metal that needed to be removed might also weaken the crank. Carillo or Rosten rods would be nice but having not seen a reported failure of the standard rod, we chose to use just that, standard rods. The Volvo ones, placed next to the standard T4 ones have an extra ridge on their beam so they do at least look stronger!

Reply With Quote Quick reply to this message
  #17  
Old 06-04-16, 21:35
kwempe kwempe is offline
Van Pro
 
Join Date: Jan 2013
Location: Bedfordshire
Posts: 64
Default Re: T4 2.5 tdi race engine build goal 300 bhp+

Quote:
Originally Posted by slimjim View Post
I'm confused by a lot of this...

Why would, for example, a factory twin valve spring setup be "best" over say a Rosten performance spring setup?
Same thing for say a stock pump (which was no-where near strong enough for clean atomisation on my setup) be better than a balanced 11-13mm upgraded United Diesel pump...?
I think I covered valve springs ok but I'll throw my thoughts into the mix on pump plunger size in the diesel injection pump if you like?
"Your" Keith does have a valid point and here is why....Grab your garden hose and remove the trigger spray from the end, what happens? Instead of spraying, the water just pours out with little pressure or force even though the actual flow has increased and you would actually fill a bucket quicker. By using injectors with bigger holes you have actually carried out a similar procedure as to removing the spray head from your hose. By reducing the restriction placed ahead of your pump plunger, you have reduced the pressure that it can supply and although you get more flow, the spray effect is reduced and atomisation will suffer. Going back to your hose then, disconnect it from the tap and call in a handy Fireman to connect it to his pump that can achieve a higher flow rate than is capable from your tap. The lack of much restriction given by removing the spray head is now irreverent because the pump will still pump at a very high rate with it removed and it will spray very well indeed!
The Firemans pump, in his appliance, could be likened to increasing the plunger size within your injection pump if that makes sense?

Oh and I didn't mention that ARL is the engine code for a TDI 150, PD engine Golf, sorry I failed to elaborate on that
Reply With Quote Quick reply to this message
  #18  
Old 06-04-16, 21:51
kwempe kwempe is offline
Van Pro
 
Join Date: Jan 2013
Location: Bedfordshire
Posts: 64
Default Re: T4 2.5 tdi race engine build goal 300 bhp+

Quote:
Originally Posted by 10 stallion View Post
This is my quest to build 2.5 TDI engine that can handle 300 bhp or more.
Nice work Andy, well done for sorting this lot out and actually documenting it too, gotta love machinery!
Reply With Quote Quick reply to this message
  #19  
Old 06-04-16, 21:53
adamss24 adamss24 is offline
Van Master Jedi
 
Join Date: Jan 2011
Location: london
Posts: 636
Default Re: T4 2.5 tdi race engine build goal 300 bhp+

The old AFN engine used twin valve spring setup and a steel taller to stop the spring wearing a groove in the soft cylinder head. The AJM Pd115 rods are the next best thing compared to the stock VE rods but- as i did not compare the Volvo rods- i cannot tell for sure if they are any stronger ! The cracked rods were a technological leap and as mentioned above spread the load on the rodsand not on the bolts.
I always use the AFN inner springs in my builds and retain the outer springs however the aftermarket springs are a bit overkill in a daily driven motor.
I would suggest going with a modern GTB turbocharger, a gtb1756vk will be quicker on boost than the stock k14 turbo and sustain 2 Bar of boost without much bother and be happy at over 260 Bhp, however i would use a gtb2060vklr as it's just the best ball bearing turbo with lightning performance ! I have done many hybrids and some are really fine IF you choose components carefully but they are no match to a similar sized stock gtb turbo ! As i mentioned in many of my posts, i tend to use turbos less than 10 year old technology !
Reply With Quote Quick reply to this message
  #20  
Old 06-04-16, 21:56
10 stallion's Avatar
10 stallion 10 stallion is offline
Van Guru
Official MemberVW Transporter
 
Join Date: Mar 2013
Location: Bedfordshire
Posts: 110
Default Re: T4 2.5 tdi race engine build goal 300 bhp+

Quote:
Originally Posted by kwempe View Post
ARL headbolts are widely recognized as being the spherical appendages of a K9 among the TDI forums when tuning 1.9 tdi VE engines and as Adamss24 says, so are PD pistons. The PD engine was and still is way ahead of its time regarding astonishing levels of torque from quite a small capacity engine. Extreme "in cylinder" pressures meant that VW had to apply special consideration to the strength of its internal components. What do I mean by extreme? How about around 4000kgs of force being applied to the piston crown on each combustion cycle, yes four tonnes! Obviously only at full chat This meant using fractured big ends on its conrods, whereby they are actually broken rather than machined and a broken rough surface left on the mating faces so that the friction of the parts is massively increased as to avoid "spread" of the big ends under extreme load. Tapered small ends were also used so that the rod passes its downward load sideways into a corresponding taper in the piston gudgeon pin abutments to reduce load on the surface that acts on the pin itself..

We did consider using PD pistons and rods but cost became prohibitive when other factors were taken into account and having seen Shadowmaker push this engine to much higher limits, we chose to use the standard, unworn, pistons again. Cost would be high because an 81mm bore is used and as such we would need brand new 2.0tdi pistons with the 4 valve head pockets machined off. We also found that the big end part of the conrod was wider and as such would need milling to fit the journal for which it is to run on the crankshaft, this would reduce the benefit of using this rod for this application. Of course we had considered regrinding the crankshaft to increase the journal width too but the amount of metal that needed to be removed might also weaken the crank. Carillo or Rosten rods would be nice but having not seen a reported failure of the standard rod, we chose to use just that, standard rods. The Volvo ones, placed next to the standard T4 ones have an extra ridge on their beam so they do at least look stronger!

WOW thanks KEITH( Kwemp ) that would have taken me a month to write if i could . You are my wizard many thanks.We to strive to be better.

Luck favours the prepared mind
Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the VW T4 Forum - VW T5 Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Location
Where you live
First Name
Surname
Postcode
Postbit Orientation
Change the display of the avatars and members types.
Insurance
Please select your insurance company (Optional)
Body & Engine Type
Tell us about your van.
Date of Birth
Your date of birth and age are displayed in several places on the forum. Only the administrator will have access to your date of birth should you choose to hide it via the privacy option below.
Month Day Year
     
Privacy

Log-in


  • Thread Tools
    Display Modes

    Posting Rules
    You may post new threads
    You may post replies
    You may not post attachments
    You may not edit your posts

    BB code is On
    Smilies are On
    [IMG] code is On
    HTML code is Off


    All times are GMT. The time now is 17:23.