Crossflow rebuild

[West7se]

Well yesterday I did a compression test and found the figures woefully low

 

1600cc 711M

 

DRY

1 - 150

2 - 120

3 - 125

4 - 120

 

WET

1 - 160

2 - 140

3 - 145

4 - 120

 

From that it can be seen that cyl 1 to 3 would appear to be rings and cyl 4 looks like a valve issue.

 

I will be re-ringing all anyway, without a stripdown its hard to say what state the bores are in, but oddly the car still goes like stink and had a great battle with a modded Vauxhall on the lanes yesterday, he did lose out I am pleased to report .

 

Anyway the reason for the post is to ask -:

 

Is there anything in particular i need to look out for with this stripdown ( i already have the Haynes manual on the engine), any hints or tips?.

 

Also what would your recommendations be for a small to medium tune up, cams etc?, already have twin webers and a half decent exhaust manifold and will go to ecu controlled igni at this point.

 

The car will be off the road in around 4 weeks so that gives me a bit of time to plan this out, no rush to complete the rebuild however.

 

Rich

[KiwiBirkin]

Hi Rich I cant comment on the strip down and build but would love some info on what you are planning for the ECU contrilled ign as im thinking about the same thing for my crossflow.

 

Cheers Stephen

[West7se]

Hi there Stephen ,

 

ECU is custom made, a good friend of mine makes them in his spare time, he works for BAE systems on the electronics division, so what he doesn`t know isnt worth knowing, lol. We did some testing at an old airfield some years ago to give the unit a real shakedown.

 

I ran his system on my old sprint car and took 1.5 seconds off my best time with just that fitted instead of the aldon dizzy igni. I just need to get a front pully milled up to complete that fitment.

 

As the build progresses I will post more on it.

 

Rich

[TheDingo8MyBaby]

Did you want to bore it out to get more displacement?

 

Forged pistons are a must on high compression crossflows. They tend to fail at the ring lands. I've never driven one, but I hear a 244 cam, while being rather high duration, is a good match to our lightweight cars. If you want streetability, go with the 234. Upgrading to an electronic ignition also seems to be a worthy upgrade.

 

Whatever you do, make sure you use oil with a ZDDP level greater than 1000. Over here in the states they've stripped it out to keep catalytic converters in better shape and it's wreaking havoc on cars with flat tappets like our crossflows.

[West7se]

Well depending on the state of the bores and the sizes of the existing pistons, yes I may well go for a bit bigger. Agree on the 234 cam, from posts I have read on some Ford sites this does seem to be the best one for street and the odd trackday.

 

I have been reading the oil thread on here with some interest, so yes I will make sure about the zinc addititive the next time I refill it. You seem to have the same issues that we have, first they stopped the old 4 star fuel, then they want all old cars/engines off the road - when will it ever end.

 

They will be blaming the kitcar industry next for keeping all the old engines going......... anyway they want us to be green, I am, I drive a recycled car - you cant get much greener than that.

 

Rich