The Cal-look Lounge

Hey guys
Trying to help a mate out , he dyno,d his new engine yesterday ,
2276
gt34 turbo
turbo smart waste gate 1lb spring
tcs10 cam
490cc injectors
48 jenvey tbs
dta s40 pro ecu
o44 heads  38,42 valves
7.5-1 comp
189bhp peaks at 4750 rpm
it don't want to rev higher than that ?
any ideas/ help
much appreciated

cheers

jamie

I wouldn't expect it to go much higher with that cam, I pressume thats a 7lb spring not 1lb? how much actual boost is he running?

cheers richie

I  will ask , I did tell him to get on here
its great! and easier than me being the middle man  :D
out of interest what cam would you use with his spec ?
oh its in a bus too
thanks for your help

cheers

jamie

If he will change rockers to 1.4/1 ratio then a fK44,if not then step up to a tcs 20 as a simple upgrade,what size is the header tubing?

cheers richie

not sure on size its a speed shop turbo exhaust ?
spring is 1 bar not lb , 15psi boost


cheers

jamie

Ok thats even worse then,it should make more than that if it were N/A,I definately think the cam is holding it back,did they have any detonation issues with 1bar boost? does it have an intercooler at all? A picture of th eengine bay with everything installed would help to show if there is anything else obviously restricting it

cheers richie

189 : 14.7 psi = 94.5 hp NA from a 2276. I would check everything and change cam like Richie have said.

BB

thanks guys , he has a intercooler , waiting for him to send a pic , will put it up when I get it .
what kind of bhp would you expect with this kind of set up ? ball park figure ?
so the cam is the restricting factory ?
his internets down at the mo , so hopefully he will get on here when its sorted
cheers

jamie

[img(http://i268.photobucket.com/albums/jj37/reijo73/C5303503-591D-4C26-969F-FFC8BF2A3FF3-738-0000011ABDE4DBA8_zpsf745ab2c.jpg)][/img]

[img(http://i268.photobucket.com/albums/jj37/reijo73/E6133F30-D5AA-40CC-B467-EB04CBBF576B-738-0000011AB0271D76_zps0749062f.jpg)][/img]

If the 2276 produces 120 hp NA (which I think it should do) and you add 1 bar of boost will produce 240hp. Add 1 more bar of boost and you have 240 + 120hp = 360hp. A really good turbo engine will produced more. I think that a decent NA 2276 engine should have 150-170-180 hp.

BB

If he were running wedgeports, sure. But we know nothing about the heads except the casting and valve-size; it could have stock ports.


If the heads have no port work, 187hp at the wheels isn't far off from BeetleBug's estimates. FWIW, being the middleman in this trouble-shoot is going to be frustrating, because without knowing how much port work the heads have, any estimate of how much power this engine should make is a wild@ss guess, at best.

The information you relayed about the turbo is suspect. GT34 doesn't correspond to any GT-series turbo Garrett makes. Perhaps it is a T3/T4 turbo? Even then, with the wide range of sizes possible within this class of turbos, we couldn't ballpark how much power this engine should be making without knowing the exact trim/size.

A turbocharged bus engine with a small cam: Was the owner or builder looking for a LOT of low-rpm torque? IMO, it's foolish to discuss cam changes not knowing what your friend wants out of this engine, especially when we do not know what heads or turbo is being used.

To specifically answer your question (well, the one with the question mark anyway), the engine should pull past 4750 rpm even with that cam. I would start by checking the plug gaps, and shoot in the ballpark of .020" gap (otherwise not knowing the capability of his ignition system, I run .023" gap with Electromotive, which is significantly hotter than most ignition systems on the market). If the gap looks fine, then double check the EFI tune to make sure there is no overboost protection or soft rpm-limiter options turned on, or if the fuel or ignition curve makes a sudden change near that RPM/MAP.

Its difficult to tell much from those pictures,theres to much going on :o :)   Did it actually make 15lb boost? or more? or less? the wastegate spring is just a number,it doesnt mean that it will actually make that number,or top it making more if there is some form of boost controller fitted?

Got to agree with Kalle, it could make 150+hp N/A with a little compression and a cam swap,so with 15lbs boost 250-300hp should be achievable
Are the heads ported? what valve springs? single or doubles?

cheers richie  

Personally I think the engine, just as it is, has a problem.
Find it before you do anything drastic.

If you change a cam and if you change exhaust, you will still have the root cause lurking in there.

I am not a TCS cam specialist but do not tell me it should not rev at least 6500?
I am not a turbo specialist but  at 14 psi +250 is very likely.

A turbo engine with 1 1/2" inch exhaust is not the limiting factor at 14psi.

Valvetrain issue, not getting enough fuel or ignition.
Did you have a Lambda? It will indicate and eliminate fuel issue.
Check for broken springs, or other valvetrain issue by just looking at it.
Try, borrow another coil or simply get a another distributor to test with.
I can go on but start with this type of approach, then consider next step.

You are right about the head work,I was typing the exact same thing as you posted :)   you would think that as this was on the dyno the operator would notice if the spark was failing? and if any overboost or rpm limit options were cutting in.

The ignition side of the DTA is strong,I run it with no added igniton boxes with methanol and 2 bar boost

cheers Richie  

TCS-10 is same as engle 110 on intake,with less lift and duration on exhaust and ground on 112lobe centers, i would think it would be done by 5000rpm, and its DTA EFI,it was being dynoed so you have to trust the dyno operator to give enough fuel and correct spark,I know that doesn't always happen ;)

cheers Richie

Just guessing, since we don't know, but if this engine has unported heads and a small turbo, then 190hp@wheels/230hp@crank is reasonable; it should be a torque monster.

I can also agree with the comments about the dyno operator, *if* they were tuning it on the dyno. Again, this could just be info lost in the relay, were they there to tune or just see what it runs? If they were tuning, what did they attempt to troubleshoot the RPM "limit"? I guess I'm confused as to whether this problem is a "this is what it made and we're confused about it", or "we tried XYZ to get this engine past 5K rpm for over an hour and nothing seemed to help".

Good to know DTA has some spark behind it; check the gap and shoot for low-20-thousandths, make sure resistor plugs are being used, etc.

FWIW, I agree that power would be dropping off by then; I'm reading this "problem" as they can't get the RPM to increase past 4750rpm (as if spark blow-out, a misfire, fuel or ignition limit is preventing it), rather than power peaks then drops off significantly after 4750 rpm, even though it will still pull to 5500rpm.

TCS-10 is same as engle 110 on intake,with less lift and duration on exhaust and ground on 112lobe centers, i would think it would be done by 5000rpm, and its DTA EFI,it was being dynoed so you have to trust the dyno operator to give enough fuel and correct spark,I know that doesn't always happen ;)
cheers Richie
[/quote]
My point is only relevant to what I have experienced and not theory, then I would express that.
Peak HP might come in at a certain rpm but not stop revving.
The reference I have is a T2 engine with a Wade supercharger on top. I bought the engine and I was not 100% sure what was inside.
It stopped revving at 6400-6500 and just would not go more.
I took the engine apart.
It hade very heavy 911 valves and 911 springs. This is a OHC combination. Not for pushrods.
Now the cam was a Scat C20. That is as close to stock you just can get.
What stopped the thing to rev? Cam, heavy valves, underspringed, out of air through the SC? I do not know but all could contribute. It still did 6500 rpm.

As for dyno operator, 100% agree, he/she should really give you a hint. Or did he/she stop the run due to knock, fuel or other reason? We do not know.

Isnt that the wonder of the internet?,we all read something and interpret it in a different way,I see that as power peaks at 4750rpm and drops away and you see it as it wont rev past that rpm,but really I think Frallan has the correct answer :D



 :o ;D

cheers Richie

heads are ported , single springs , no misfire etc above 4750 rpm
chromoly push rods were not set to 0 (the only thing I knew was off  :D)

sorry pics not the best

last convo he said, they said about spring resonating !
so maybe its answered the questions right there 1

the owner is waiting for his registration to be acknowledged
to join us on here , so sorry to all if my middlemaning has
missed /made stuff harder .

he is waiting to get the printout emailed to him
so he or I will post it up when it lands .

cheers for the help/knowledge guys

jamie
 
 oh and it seems to be hard to find people willing to work with DTA ,
why is this ?

It is due to the fact that it take ages to map a engine with a DTA ecu compared to the more popular ECU's out there.

-BB- (DTA S60)

Single springs and 1 bar boost...?

My old 1914 efi turbo motor ran a regular Engle110 and made peak power (207rwhp @ 22psi) at c.5600 rpm but pulled through 7k if allowed, heads were SCAT super-D port.

It could be SO many things not quite right or combination thereof - good luck  :)

Thanks Reijo5 for all your help

Hi guys I am Jamie who owns the engine.

Irl give you a quick run down. The last engine I had built (2007) turbo I took to Jamsport in Northampton to have tuned just before bug jam. When collecting the bud the tuner said it has an exhaust blow and I would need to fix it before he could go any further. Returning to my lockup and running the engine I found it had split a barrel, so fixed it and drive it to bug jam. It never felt right and got very hot and would stall in traffic the not like to start. The reason I've told you all this is because when I took it to Rapid rodent racing on Thursday to have it tuned they really seemed to know there stuff, asking me questions that Jamsport never did. I trailed the van to Rapid rodents premises and we got the new (2276) engine running and as soon as they got it on the laptop and read the original (jamsport) map he said he didnt want me to drive it as it could do allot of damage. The TDC was not set, the ignition map and fuelling was all over the place. We trailered it to the rolling road and started setting things up, instantly the engine barked into life and sounded Right! At this point I really new the bloke knows his stuff, after setting up and tuning on the dyno Run after Run it got better and better but would rev to About 4750 then just drop off/loose power! After more tuning it did the same. We popped a rocker cover off and saw that it only has single valve springs. They seam to think that the valve springs in the heads are not strong enough to hold the valve shut and are being pushed open with a mixture of valve bounce and boost pressure?
When I bought the heads they came with another 8 springs in the box, not twin valve springs but another set the same size.

I have bought the best I could afford of everything for this motor as I expect it to be a 300bhp motor.

The heads are AJ Simms hand ported Turbo spec 044s. (Maybe wedge port)
Scat volkstroker 84mm crank (I think it's 84mm) all lightened n ballenced  (pulley to plate)
Scat H beam 5.500 rods
Nos Mahle 94mm barrels
Wiseco Pistons
Cb super mag case
Cb straight cut cam gears
Engle TCS cam
CB wide foot followers
Steel backed main bearings
Chromoly lightened flywheel 8 dowel
Stage3 pressure plate
Cb duel friction clutch
Scat 1.25 rockers on bolt up shafts
Chromoly push rods
30mm shadeck oil pump
48mm throttle duel bodies with 490lb peco injectors
Home made charge cooler and torbo inlet 2"
Turbonetics T3/T4 hybrid turbo (unknown spec)
Turbonetics 38mm wastegate
Stainless Speedshop turbo header
DTA s40 pro ECU
2.5bar map sensor

I need to get a air temp sensor (RRR told me this) so it's on my list and will be fitted before I take it back.

I will post the session printout as soon as I get it as hopefully this will halo sort my issue.

Thanks for everybody's input so far and I hope we can sort the problem! Thanks

Jamie

I would agree. Granted, I run singles, too...but they push about 420lbs over the nose. Yours probably don't, and switching over to duals may indeed solve the problem.

I've got similarly specced engine with TCS10, now built for turbo use with 8:1 compression, ported 044's etc, with dual springs. I ran it N/A last summer with IDA:s and MSD spark. It's peak power was on about 5300-5500 and easlily revved up to 6500 with not very noticeable power drop. This same engine was dynoed a couple of years ago with wilder cam (Webcam 86c) and more compression (10.4:1), it produced 169hp with 45DRLA's. Now with this new incarnation, my fine tuned ass dyno said it was producing ~150hp last summer, and quite a lot of torque even without any boost and with a bit too rich fuel mixture.

This engine was used in our race car, and compared to high-compression - wild cam combination, with TCS10 the car was much easier to drive, produced very wide and usable power/torque curve and still revving high enough that overtaking with 3rd gear was easy.

I'm planning on more moderate boost, something like 0.4-0.6bar (6 - 9psi). I'm not sure if I believe myself that this moderation in boost is going to happen :P

Hopefully you'll get the problem worked out! 300hp may be a long reach without over 1bar / 15psi boost and wilder cam, but should be easily somewhere around 240hp and few broken gearboxes with torque!

2276cc is 82 x 94.... power drop off @ 4700rpm indicates induction choke, valvle float (very likely possibility with singles especially if not HD singles), wrong valve geometry, maybe even cam/lifter compatability.
These are only my non expert "maybe" causes of your lack of power......that engine @ 1bar and all stars aligned should be producing around 220HP.

Good luck with it considering you have some nice parts invested in this engine.

Fuel map may be to rich up top also. Or to much fuel in the boost comp map.

Thanks guys, this is the printout!

(http://i410.photobucket.com/albums/pp189/RATBAG66SPLIT/E683E1C8-5DD2-4EA1-8BAF-51B59A97F062-424-00000016F9E65337.jpg)

No fuel log?

Now I am guessing.....

Fuel is not the issue if the dyno operator is not totally lost and out of his mind.
Less likely but not imposisible, ignition issue. Operator should be able to tell you.

Now with the information we have, my gues is single springs.....the drastic drop off, i.e. valve float.
That is not a natural power drop off, or cam issue or exhaust restriction.
It is a serious cut off.

+1000 to 1500 more rpm is hidden in there and plenty of more hp.

Verify the fuel and ignition first, then in any case, get a good double spring setup if you intend to go anywhere.
Or....as an afterthought, a good single beehive retrofit. Now I am not sure if that is that option is so easy.

I agree with all above and I would also check for any boost leaks.