The Chinese Engine Build

lwarrior1016

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What are you thinking here? Maybe the heads are lifting? The hp does seem a little low but you went with a pretty small cam this time, right?
 

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we appreciate people sharing mistakes so we can all learn from them. Is it normal to have so much timing? I ask because I think I have mine set at 20 degrees but it was supposed to be a conservative tune
 
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No, I do not think the heads are lifting... yet. I had that problem on a Terminator motor at 560 HP that made me crazy for years.
Here are some numbers on some of the other builds.

Trick Flow Heads 38cc
13.5 CR 271 ave. compression
285 RWHP/ 305 RWT
Bullet Cams 221/226

Ported NPI Heads
13.0 CR
250 Ave. compression
256 RWHP 262 RWT
Bullet Cams 221/226


Trick Flow Head 38cc
10.4 CR
216 ave. compression
312 RWHP 325 RWT
Bullet Cams custom TF
230/236 .570" lift



So there is not much difference when using a NON TF cam on the first 2 and then a bigger cam made for TF Heads is a big jump in results, the Custom TF cam is smaller than the TF Number 1 cam they sell so bigger power and sound should be on point.

The engine now is very smooth and revs to 6500 easy but the rev up is slower from the PI intake and stock exhaust manifolds and lower timing.
 
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On the timing.. the TF at 10.4 CR went to 32 degrees total advance and did not knock but made no added HP so it was set at 28.
This engine was knocking so they had to pull the timing down and I think that is where the power loss is coming from so..
Do I use some thicker head gaskets to drop the CR by half a point?
I have no E85 around.
 

96blak54

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No e85 but im sure there is fuel with 10% ethanol
Like speedway or BP.

Using the smallest injector possible is ideal. This way the injector time is extended throughout the stroke instead of dumping it in early in the stroke.

We gotta get that exhaust valve opening delayed. I have you a set of lashers im sending you that will do this a little bit but not like it should be. Youll want to target valve opening at BDC or a few degrees afterwards when rpm is high.

By the specs youve issued and me assuming the exhaust lobe base circle is standard, your exhaust opening is 45° BBDC. If the base circle is under standard diameter, ex opening will be closer to BDC, but its any ones guess where at.

The cams set roughly around 106 - 107 intake centerline, all other valve points make real good assuming the use of stock valve springs with no shims set at standard height.

IVO is 4.5 ° BTDC
IVC is 36.5 ° ABDC
EVO is 45.0 ° BBDC
EVC is 1.0 ° ATDC
Overlap is 5.5 °

Intake opening 4.5° before tdc and exhaust closing is real good for idle. But when upper rpm come in play , that exhaust valve will float a good 10° before closing, aiding in overlap. Same with the intake closing. Its gonna float a good 15°-20° or more cause its a heavy bastard! Putting intake closing more at midbore

Its the 45° BBDC exhaust opening thats killing your power. Their is still 45° more push. Especially with a 1.4" valve thats nearly half the diameter of the piston....meaning their wont be any trouble with exhaust blowdown. With that much ex valve opening, i would assume the cams to be a supercharger grind, but im reminded cam grinders mass grind with ex openings not tailored to one individual build. Superchargers need early ex opening for more exhaust blowdown before pushing the rest out on the exhaust stroke.

Taking material from under the lasher is the easiest solution. Either the bottom side of the lasher(not much there) or from the lasher pocket in the head. This will alter exhaust opening by giving the lasher more time to decompress into its stop point. Paired with a sloppy lasher would add more delay. Of course this changes the entire ex valve event and lifts, but in my opinion, its negligible with that 1.4" valve thats known for passing 800hp through.
 
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Thank you for your input, I think an easier way is to trim the valve stems down...
I got the tooling.
Let me check the injector math, I forgot to take a set of 19 pounders with me when I went to the tuner.
I am using NGK TR-55 plugs which are 1 stage cooler and the look clean and learn to me but my wide band O2 levels look good.
 
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I am pushing the numbers around on the BSFC from .45 to .50 and I am at the limit for 19 pounders, the numbers are coming in at 19-21 depending and I have 24 pounders in the engine right now.

I posted the NPI engine above to show how good the heads are..
The porting job on that set were not that good and too big and the numbers look good for all the hate they get. The secret is to barley touch them and keep the port velosity as high as possible for the small piston size of the 4.6 and 5.4
The long runner PI intake helps the stuffing.
My max ported PI heads are 180cc ports and that is a lot of cutting and polishing to get there with sets of heads to learn on and destroyed engines as they fail.
I think my port velocity is too low with this head.
I might try a smaller 70mm TB and see....
 

96blak54

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I gotta finish this set of lashers for you and ill send them. I took .015" from the bottom and they are old lincoln 4v that bleed easy.
 
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IMG_0081-D.jpg
 

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