Peppy's Build Thread

[xr6tForMe]

Thanks Joe.

I would love to see anything you post on how this goes.

[JETURBO]

Looking good joe !

[turbotrana]

Have you had any thoughts about the chain tensioner. Its probably an area that I would look further into if doing a big build.

[Peppy_t92]

Have you had any thoughts about the chain tensioner. Its probably an area that I would look further into if doing a big build.

What would be your concerns Tranna? I am actually re-thinking the whole timing kit, is there a better stronger option? Atomic? Genuine?

Anyway I'm getting back on track, I went to Powercruise Friday night, and realised that there is 10weeks until Powerplay which I have already paid for my garage spot and I'm not missing out! Tick Tock, I want to be sure I leave enough time for testing and tuning, so I've given myself a 6 week timeline! Which "should be sufficient"

We focussed on the exhaust side this past week and will get to the intake next.. Exhaust flow is crucial for a boosted motor and should ideally Flow 90% of what the intake flows, so we will see how we go.

Basically, dad and I started to look closer into the Head, firstly looking at the gaskets and manifolds, first up noticing that the bolt holes in the exhaust manifold are 12.9mm and the bolts are 9.8mm so 1.5mm play each way, essentially blocking 1.5mm of the exhaust ports because who lines them up properly when fitting? I never have.. I spent abit of time cleaning up my turbo manifold last time I had it off so it's already better then a standard manifold but obviously the ports will be out if not lined up... Also the manifold to turbo flange is quite far out, which I match ported last time, so might be worth a look on all of yours...

I made some sleeves to take up the slack only on the far left and right corners they line up the manifold and gasket quite well, then match ported the gasket to the manifold then scribed it to the head

My matched gasket sitting over an untouched gasket

Now to do some measuring of the wall thicknesses to see how much meat there is to play with.. We have some hand made very technical devices to achieve this haha, as well as a rubbish head that we have drilled in certain areas to check the spots inside water jackets etc..

I flow tested the exhaust port as it was, with the standard valves etc to save a good base, it flowed well with dad comparing it to a ported VN head... There is a feature of this flow bench that allows you to measure where the air is actually flowing, so you basically map out the port.. We tested it at 0.05", 0.1", 0.2", 0.3", 0.4",0.5" lifts

https://vimeo.com/122387529

https://vimeo.com/122387563

The basic theory behind airflow is that Air will take the shortest path and follows line of sight, so theirs a couple of key areas that "generally" pickup flow.. Short Side, Roof, the Guide Boss and Bowl...

The short side helps to obviously shorten the Airflow Path, create a nicer curve and create a bigger bowl area.. Making a bigger Bowl/Throat area helps to slow the air down as it enters the port and help it turn the corner, which actually promotes flow.. The Guide Boss and the guide sticking out is a restriction, by slimming and smoothing it out your gaining flow.. The roof is where the air wants to go, you may be familiar with the old Clevo Heads getting "high Ported" where they actually fill the lower section of the port and weld extra metal at the top and grind it away to essentially lift the whole port up... Generally speaking there's no reason to touch the floor of the port, you can actually loose flow and velocity (Air Speed)... There is a lot more to it if you wanted to go to the effort of measuring cross sectional area and calculating a perfect volume for the length of the port... In saying all this I'm just a Carpenter haha, I have given my understanding of what my Dad has told me, so don't take it as gospel ...

Now the grinding gear has come out, a big Hitachi Die Grinder with Varied Speed Controller, a selection of burr's, long, short, fine, course, stone, sandpaper and different shapes...

Dad is Grinding the head and I'll match port the manifolds haha, anyone can swing a grinder but getting each port smooth and exact is an art that I haven't achieved yet.. He basically ported it just as I explained above.. We worked out that we can afford to raise the port by about 2mm with the the Std manifold.. If using a custom exhaust manifold you can go abit more and round it off abit more to take advantage of the larger round pipe.

Back on the flow bench so see the results. Remembering that the seats still need to be cut then the port tickled up and polished with the sandpaper wheel...

It picked up at all valve lifts, more so at low lift which is where the valves spend more of their time anyway, but an average of 12% more flow was achieved

Anyway, that's enough for now, I'll keep use updated

Thanks for reading, Joe

[k31th]

fantastic work mate, great write up and looks like very good results so far Boosted engines love smooth airflow

[eff xr6t]

Awesome work mate love seeing someone doing all the work himself instead of just handing over cash to a shop!

I should send you over a single cam 4 litre head to port and I'll test it out on my motor haha

Sent from my iPhone using Tapatalk

[MattyP]

Hey mate

You keen to work on my celica at all lol

Looking great

What's the plan with the gearbox?

[JETURBO]

Top work joe love this stuff !

Remember those guide bosses not only take up space but play a vital part in valve cooling so its a big balancing act that you cant see unless you start using thermocouple per pot at tuning time

And then u need to know the valves limit :/ always a risky part

Kicking on dude

[Peppy_t92]

Thanks guys,

Haha once my car is done I'm happy to help..

I'm still avoiding the box until the engines done, I'll probably tear it down when is end the motor for its next stage of machining... I'm still keen to give it a go, and any technical tips are appreciated haha...

Yea we understand that, it also give the valve less support so it may move/wear and more chance of picking up on the guide... It's standard length is 1.8" it has been shortened to 1.55" so we will see how it goes

[Peppy_t92]

These pics didn't come through in the other post, hopefully they work now

Edited 17/03/15 08:28 AM by Peppy_t92