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kpr's starlet

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ah yeh. bigport or smallport? mine seems to be ok now with just the factory external drain and the big breather. gave it a good thrashing around some corners etc.. the other day. seemed all good. circuit will put it to the test though.

yeh sounds about right. pretty damn expensive. if you get someone half decent they can ask tnz for a special price, the more of the same size you buy the cheaper they seem to be

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Mines a big port head, on a ZE block, with silver top crank/rods and wiseco pistons. I did lots of hill climbs and club events with mine, and not a drop of oil came out, but as soon as I got on the track, bang, mega oil mess. Mind you that was with a blue top block, so had super shit oil drains. Im keen to get some meaner cams when I do the next rebuild, I guess the solid lifters would work out a lot cheaper then a shim under kit?

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yeh the shim under bucket kit from kelfords, was more expensive than the cams themselves.

was gonna be real expensive to go with there hi velocity cams and the double valve spring shim under bucket setup. . i allready had the correct valve springs, for the stock shim ones. so went with the biggest stock shim ones they had. got the 1sz buckets for piece of mind and old ones were pretty worn.

circuit will put it to the test though.

Bringing it to OS Trackday?

pretty keen aye, depends if i can sus out someone to drag along/pit crew. since its a bit of a mission from the rei

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It may or may not help to know this:

My pushrod Mk1 Cortina race motor was strong inthe midrange but the power fell off up high. The top end was terrible and the power bassically switched off at 6,900rpm

I replaced the ignition system with an MSD system. No improvment.

I re-jetted the existing carbs. No improvment

I replace the carbs with near new larger webers. No improvement.

I changed the camshaft: No improvment so I then replaced the valve spings. Nada.

I changed damned near everything else including the header lengths: No improvment.

The I looked at my super expensive merge collector and megaphone (built by some expert dude in CHCH) and though :doubt: I wonder? It was expensive so I didn't want to touch it. :oops::cry::(:?:x Stuff it. I cut it off and substituted a straight bit of pipe. Instant improvement! The megaphone had been the problem all along and some wierd shit was happening with shock waves or something that was stopping the motor reving.

The above may not be even slightly related to where you are at l but I thought I would mention it anyway as you can always ignore me.

Nice work mate. Beautiful skills

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hmm interesting. i have been tempted to try a straight piece of pipe as you say. but same deal didnt want to cut up my extractors etc.. another thing ive noticed when removing the extractors this last time. was the colour of the tube right after the collector, where it has a short section of tube about 51mm id, between the collector and megaphone. looks to be getting quite hot at this point. so possibly a restriction at high rpm. but good for scavaging at low rpm. i also noticed a huge power gain from 4500- 6000rpm when changing from a 2" exhaust system to a 2.5" system.(from megaphone back.) there was a flat spot at 5500rpm before this change. car didn't seem to gain anything past 6500rpm. its given it a huge powerband. almost to the point you don't know what gear you should be in. sounds great, but doesn't seem right.

maybe cutting the collector back and running a 2.25" pipe for a bit then into the 2.5" system is worth a try?

at high rpm it seems very numb to any changes. this na stuff is pretty tricky. not like the turbo stuff im use to!

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the colour of the tube right after the collector, where it has a short section of tube about 51mm id, between the collector and megaphone. looks to be getting quite hot at this point.
I think I recall exactly the same on mine. There was a thick layer of white deposit there (mild steel construction). After that point in the exhaust my system megaphoe went out to 4.5 inches and had some swirl arrangment inside it.

I will see if I have a photo but basically the thing was more than a total waste of money as I spent a year an several thousand dollars trying to make the engine go properly due to my hgesitation in chopping off something that someone else charged be a bunch of cash to make.

The emperor's new clothes..........

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wish i could run my exhaust thru the cabin! would solve those ground clearance issues

bit different to what i have on mine. goes from about 2" to 3-3.5". one other thing ive noticed is the car will hardly run when the exhaust is removed after the megaphone. off the scale lean in midrange.

what size pipe did you replace the megaphone with?

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^ The entire system is currently 2.25" but the engine builder (yes I am too chicken to do my own engines these days) is very keen to go down to 2".

He could well be right and a new exhaust is in the planning/funding stages.

The 2.25" is based on a 1641cc engine. My new engine will be of smaller capacity as I have also become terrified of over boring too much and cylinder sidewall collapse/ovalization.

To finish first, first you must finish (cluck cluck).

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Was that just regular perspex you used for your airbox? Did you bend it up yourself or get someone else to do it? I'm wondering whether that might not be a bad idea for the C110, cheap and easy enough to work. Or would any fuel or fire that may come out of the carbs cause the perspex some issues?

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yeh was just normal stuff far as i know, mate gave it to me. its pretty easy to shape. heat it with heat gun, then bend using a straight edge. just don't over heat it else it starts to bubble. i used superglue to stick it together. then ran a bead of silicone around the joins. theres probably a better way to stick it together, but hasnt broken.

only issue ive had is its got a few small cracks in it. but possibly happened due to it hitting on the brake booster. biff it in a tin of gas and see what it does maybe?

Unclejake: stick with the big exhaust i recon, i gained nothing but happy times going bigger. tune the exhaust to size & length then dump into biggest exhaust possible (within reason) maybe worth a go.

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Ah ok. Sounds like a plan then. I'll keep you updated with my progress should I go that route once I've got the trumpets, depends on the clearence from the sidies to the inner guard etc.

Also, the L is non-crossflow, so unless I run a shield between the headers and the intake, it may well melt. Considering how easy it is to form, it's likely a distinct possibility. :lol: Guess we'll find out.

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hah, yeh might start to mold itself around the exhaust. how about a fiberglass one? may hold up to the heat a bit better. thinking i might use my current perspex one(or parts of it) as mold for a fiberglass one. as unsure if its going to fit with my new manifold setup.

you could allways do the same if its starts to go out of shape with the heat.

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Kpr's acrylic is actually pretty hardout stuff and worth a small fortune, but if you were to replicate it then just use any cast acrylic, I would recommend 4.5mm over 3mm to give a slightly better joining surface. Best way to join is to use Chloroform which melts the two together then run a beat of Weldon16 over the join to strengthen.

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the colour of the tube right after the collector, where it has a short section of tube about 51mm id, between the collector and megaphone. looks to be getting quite hot at this point.
I think I recall exactly the same on mine. There was a thick layer of white deposit there (mild steel construction). After that point in the exhaust my system megaphoe went out to 4.5 inches and had some swirl arrangment inside it.

I will see if I have a photo but basically the thing was more than a total waste of money as I spent a year an several thousand dollars trying to make the engine go properly due to my hgesitation in chopping off something that someone else charged be a bunch of cash to make.

The emperor's new clothes..........

cut out the megaphone today. now it has a section of 2.25" (300-400mm) welded to collector. then steps up to 2.5" for the rest of the exhaust. afr has stayed the same. but it accelerates faster. no loss of power down low. thinking i might try 2.5" all the way .

least im going in the right direction now anyway, slowly!

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cut out the megaphone today. now it has a section of 2.25" (300-400mm) welded to collector. then steps up to 2.5" for the rest of the exhaust. afr has stayed the same. but it accelerates faster. no loss of power down low. thinking i might try 2.5" all the way .

least im going in the right direction now anyway, slowly!

Just on the exhaust stuff you are talking about, I have always read things about small being better for velocity on the exhaust side and all sorts of things that I didn't really understand but lately I have been reading up on a lot of NA builds going for massive exhausts with no restriction. Think 3" on 2L engine making around 250-260hp! That seems crazy huge but they don't seem to loose any power. Also another page I found said that supplies extractors for the engine I want to build and they specify a minimum for 2.5" after the collector. Spence has also found similar numbers up to 3" for tuning Toyota BEAMS 3S-GE's.

Just thought I'd add that as when I put a 2.5" on my Chevette engine (on the advice of the exhaust guy) a lot of people said it was too big (and I agreed) but I'm starting to wonder if its not, with the right tuning ofcourse.

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My car had a 3" system on it originally, and when my muffler blew I stepped down to 2.5". The dyno doesn't say that I've gained any power, and cant tell if theres a difference in torque because I had a different diff ratio when testing the 2.5". I've gone back to the old diff ratio now so will tell you what the result is next time I get on the dyno (hopefully this week).

Might go back to 3" to test curiousity.

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