PowerHouse Engines

03/06/2026

Can a simple carb spacer really make a difference?

We bolted a CJS Dual Plane Carb Spacer with a shear plate onto Glenn Bamford’s 355 Holden to find out.

The result? A gain of 16 ft-lb of torque right through the middle of the curve where a street engine spends most of its time.

No changes to the tune-up. No magic tricks. Just a well-designed spacer improving the airflow path into the manifold.

Sometimes it’s the small changes that make the biggest difference on the dyno.

01/06/2026

Still on the dyno with Glenn Bamford’s 355 Holden, we decided to test a Torque Power High Rise dual-plane manifold kindly supplied by Greg Shepherd.

This manifold had only received some minor port matching and cleanup work to suit Gregs iron cylinder heads.

The results were impressive.

The engine produced 524 horsepower and 447 ft-lbs of torque, with a broad torque curve and strong power throughout the usable RPM range.

It just goes to show that a well-designed dual-plane manifold can still be a serious performer on a tough street 355.

Big thanks to Greg for supplying the manifold and giving us the opportunity to put it to the test.

31/05/2026

The PowerHouse Podcast is officially underway. 🎙️

The goal is simple… sit down with the people who have built the engines, raced the cars, made the mistakes, found the solutions and gathered decades of knowledge along the way.

Some of the best stories and lessons in our industry have never been recorded.

Let’s change that.

First episodes coming soon.

29/05/2026

For this test on Glenn Bamford’s 355 Holden, we made a last-minute decision to throw a Harrop dual-plane into the mix. Huge thanks to James Rees for tracking down a brand-new Harrop manifold on Marketplace and offering it up for testing.

The goal was simple: could the Harrop a true under-bonnet dual-plane manifold produce better low-end torque than the single-planes we’ve tested, while still having enough airflow to push towards the 500hp mark?

The results were impressive.

The Harrop produced 492 horsepower and 438 ft-lbs of torque, with a strong torque curve and noticeably better bottom-end performance than the Edelbrock single-plane. Up top, however, it eventually ran out of airflow and plenum volume compared to the larger single-plane manifolds.

Did it make the most peak power? No.

Did it prove that a well-designed dual-plane is still a serious performer on a tough street 355? Absolutely.

Full results in tonight’s short!

27/05/2026

Glenn Bamford’s 355 Holden is back on 98 octane fuel and this time we’re putting two single-plane intakes head-to-head:

• Edelbrock Single Plane
vs
• Torque Power Single Plane #002

The results were interesting…

The Edelbrock made almost 30 MORE peak horsepower — but only between 6000–7000rpm.

Everywhere else, the Torque Power was stronger.

From 3000–6700rpm the Torque Power averaged:
✅ 21 ft-lb MORE torque
✅ 13hp MORE average power

So the big question is…

Would you rather chase a big peak horsepower number… or have a combination that’s actually stronger through the entire usable RPM range? 🤔

This is exactly why average power matters — not just the glory number at the top of the graph.

25/05/2026

Replacing the old dash-8 fuel hoses on the engine dyno today.

The Speedflow fittings on it are over 15 years old… and still swivel and seal like they should.

Cut the old hose off, reused the fittings, straight back into service.

Meanwhile the old XRP and Earl’s fittings we had years ago?
Ended up in the bin—stiff, leaking, and worn out.

Just shows the quality of locally made Speedflow gear out of Taree NSW. 🇦🇺

24/05/2026

https://youtu.be/Q7UYQTEO3eM?si=qRk7mi1g8Ra2klyj

In this episode we put three popular pump fuels head-to-head on the dyno using Glenn Bamford’s 355 Holden.We tested:⛽ LMCT+ 95⛽ BP 95⛽ Shell 94 (10% ethanol)...

22/05/2026

THIS SUNDAY NIGHT ON YOUTUBE

The results are in for Glenn Bamford’s 355 Holden fuel test!
We put Shell 94, BP 95 and LMCT+ 95 head-to-head on the dyno to see what actually performs best under load.

Power figures, fuel comparisons, octane testing… and no bu****it.

Then sit back and enjoy the last few minutes of the video — we’ve stacked in a heap of full dyno pulls so you can just listen to this thing absolutely ROAR. 🎧🔥

You don’t want to miss this one

20/05/2026

A good reminder that even with modern CNC machining… things can still vary.

Today on Glenn Bamford’s 355 Holden, we checked the valve lash using the traditional method — rotating the engine 90°, putting the opposite cylinder “on the rock,” then adjusting the firing cylinder.

Once we had all the clearances recorded, we decided to test another method shown by Frank from Dandy Engines to compare the results.

Most of the readings matched exactly… until we got to Number 8 exhaust, Number 1 intake, and Number 8 intake.

Using the traditional method, those tappets measured a tight .020”.
But when checked using the alternate method — which places the lifter in a slightly different position on the cam lobe/tappet ramp — the clearance opened up to around .0245”.

That’s a pretty big difference from simply changing where the lifter sits on the lobe during adjustment.

It just shows how critical camshaft accuracy really is, and why having a good relationship with your cam grinder matters. Even in today’s CNC world, variations can still creep in.

Sometimes the engine tells you more than the spec sheet does.

https://youtu.be/dCAYtZlWz1Q?si=9puWUzGfVH1bPoJv

18/05/2026

This Arrow Cleveland block came in with a nasty surprise hiding at the rear of the block. The oil feed drilling from the main tunnel into the cam bearing tunnel had been drilled too far over — straight through into the bellhousing area.

Result? Massive external oil leak, loss of oil pressure, and a recipe for disaster if it went unnoticed.

One tiny machining error… huge consequences.