SteveHobart

Crossy build- am I on the right track

36 posts in this topic

Hey Guys

 

Well I have the engine out and ready to build a mild EFI crossflow for a bit of a fun/track car. I’d love some advice on the plan to tweak it before I pull the trigger, what I’m thinking is:

- Port and Polish on Head

- Zero deck the block

- Strip and rebuild, will be around 40thou oversized I reckon Piston wise

- Crow 14892 Mild Hydraulic Cam

- Stronger Valve Springs

- Megasquirt ECU to control both fuel and spark

 

What do we reckon? Will make some good HP?

 

 

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If your going to track race it and have a tuneable ecu then I'd forget the hydraulic and go straight to a solid.  Hydraulic Cams just can't deal with the rigours of constant mid to high rpm.  

 

The reality is a solid will make more power and way more reliably than the hydraulic. With the right springs you won't be doing tappet checks as often as you would imagine. 

 

The rest sounds good. Don't forget tomfactor in a half decent sump for track work. 

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Hey Guys
 
Well I have the engine out and ready to build a mild EFI crossflow for a bit of a fun/track car. I’d love some advice on the plan to tweak it before I pull the trigger, what I’m thinking is:
- Port and Polish on Head
- Zero deck the block
- Strip and rebuild, will be around 40thou oversized I reckon Piston wise
- Crow 14892 Mild Hydraulic Cam
- Stronger Valve Springs
- Megasquirt ECU to control both fuel and spark
 
What do we reckon? Will make some good HP?
 
 
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OK some dissection of your plan:

"port & polish" - just port, not polish. Polishing is a waste of time and has a negative effect on fuel atomisation and air velocity.

"zero deck block" - good move

"40 thou piston" - only if it needs it. Boring gives a negligible increase in displacement and power, so just go the absolute minimum to clean up the wear.

"crow 14892" - might be a tad small for what you want. I would go a size or two up.

14770 - 214/224 510"/514", 111LSA
14550S - 219/223 510"/510" 106LSA (speedway cam, a bit cranky)
14686 - 224/224 507"/507" 108LSA (also cranky)

But the one you quoted might feel a bit wheezy on the track.

"stronger valve springs" yep good move. Go at least 115lb on the seat, high 200s on the nose. I got Crane Blue Racers pretty cheap. If you want the motor to live a long, happy life, invest in some good roller rockers. The stock rockers (with stiffer springs) will burn through your oil, wear out quicker and put stress on your valve stems.

"Megasquirt ECU" - can't comment on that one but they must be OK if they're still in business.

Now some more to add:

Get it balanced (pistons, rods). Invest in a good harmonic balancer. These engines don't like RPM with an untouched bottom end.

When determining how much comp you need, focus on dynamic compression ratio, not static. This means that you select your compression ratio based on how the cam works in relation to the piston position. There are online calculators that help you with this. On an alloy head, aim for about 8.5:1 dynamic. You need to know the engine parameters to input though, which will require other calculators to find.

This is a good site:

http://www.wallaceracing.com/Calculators.htm

Be careful when shaving the head/block to zero deck the pistons. Your pushrod length will be affected.

A lighter flywheel does wonders for engine response and fast gearchanges. An 8kg zero balance 157 tooth Windsor one will bolt on.

The stock EFI bananas can start to get restrictive with only small increases in power. EA-ED logs are a good conversion, this also swaps intake piping to the cold side of the engine. If done right, the setup can look like it was made to be there.

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Thom, matt_lamb_160 and Demmo like this

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Hey mate, thanks for chasing me up. Have been pretty busy on the XF (when I get time anyway).

 

Engines out and off to the rebuilders (only for the machining). The plan has altered slightly:

 

Zero decked block

Ported head

Crow 14770 Cam

Cylinders need to be bored out, so will be 40thou oversize as that’s what’s recommended

Balance job on the bottom end

Light weight flywheel

Have gone with the MS3x ECU with the datalogging function, will just be a bit of fun!

 

Have ordered some wiring stuff (the engine bay is a mess), new engine mounts and twin 12” thermos and a Davies Craig Thermo switch. Spent an afternoon cleaning the engine bay and am cleaning up and painting the extractors.

 

So all in all, it’s progressing! Should come in around $3k for everything and should put out some (decent) figures!

 

Thanks for the input!

 

 

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gerg, deankdx, CHESTNUTXE and 1 other like this

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Oh, forgot to mention. My youngest and I went to the local racetrack for a bit of a look. There was a turbo RX7 on track and it was shooting 4 foot flames out of the exhaust. Anyway, my youngest loved it!

So the XF has sidepipes and I have worked out how to program the ECU to shoot flame, just because he likes it!

Funniest thing is, one of my day jobs at the moment is consulting for the Climate Change Office on Electric Vehicle transition for local council. Hypocrisy to the max!


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2 hours ago, SteveHobart said:

Funniest thing is, one of my day jobs at the moment is consulting for the Climate Change Office on Electric Vehicle transition for local council. Hypocrisy to the max!

 

Jay leno said each "revolution" has benefits, when horses were phased out due to cars taking over, it enabled horse enthusiasts to enjoy them still without the cruelty etc .(other than horse racing etc)

then with the electric cars, it will mean there will fuel still available for classic cars even if it's 100% ethanol etc people will still want to use them. 

be sure to add that into your consulting results.. tourism for classic cars touring Tassie( and anywhere else) will still need petrol stations etc. 

 

** i did see an electric vehicle charger at Mt Field National park and also one at Maleny Botanic Gardens & Bird World in Qld(near Australia zoo)

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Update on XF Build. Whilst waiting for the block and head to be machined, I’ve been fixing some other issues on the XF.

Have pulled the Dashboard out and have found a worn ODO gear in the cluster so have ordered some more. Have also been tidying up the paint work (a bit, it’s still dodgy as).

Still have an issue with the Speedo and not sure if what I have done will have any effect. There’s a leak in the rear seal on the gearbox so have been considering pulling that out as well (and I have heard it’s easier to put the engine in with the box attached) to fix the rear seal and the speedo gear!


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CHESTNUTXE likes this

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Hey guys. Today I pulled the Transmission out. Mainly because the Speedo didn’t work (have ordered a new sensor) but there’s a definate leak from the transmission too so don’t want to have a nice engine and a leaking trans!

So findings. There’s definately a leaking rear seal (new on on the way) and the gearbox rubber mount was literally in 100 pieces (not a word of a lie) so new one of them on the way.

My question is, should there be a switch or a sensor here (refer pic).

d3ef8d3d295da166ac95b3b0ac71e4bd.jpg

e00ab71ea041d3b0ff87a559068b762c.jpg

I seem to have an extra set of wires to clip to something but can’t seem to see what. The only thing I can think of is a switch or sensor is missing here?


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CHESTNUTXE likes this

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is that shifter boss double sided? never seen that before(when you say transmission, i take it as auto transmission, that i call a gearbox.. in particular, single rail 4 speed.)

i assume, if its a late XF it may have had a switch for neutral on the opposite side? and other one is reverse.. actually EFI may need a neutral switch? never seen one to know but @Panko or @Mr Polson may have an idea?

 

single rails leak like a SIEVE from the selector rail seal when they are old and no one has ever looked at them, get a new one, it will need the extension housing to be removed to fit it from memory. 

cant find a google pic, but here's similar from google of some random gearbox
pic53.jpg

 

 

 

gerg and CHESTNUTXE like this

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Yep, one on the shaft itself is neutral, one on the side of the shifter is reverse. Neutral switch tells computer certain operating needs for emissions, etc. Dunno what it specifically does, maybe drop the idle by a bee's dick? Advance timing to keep it cool in traffic? Thom?

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deankdx likes this

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So digging further in, slowly because work is super busy. I thought there was supposed to be a rubber mount on the gearbox Cross member, all I have is bits!

8387bff44fe65266a1b9c6b1c1f208c9.jpg


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gerg likes this

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had a few more years left.. should be signs of metal on metal wear somewhere? i've had a few like this due to oil leaks(rubbers do not like oil or grease... ;)

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Oh totally

Now Gurus, I need some help. The shifter seal on the Single Rail is one of the leaks. But how the hell do I change it? I can see the join on the shifter shaft, do I actually split this join to change the seal? How do I do that?
Any help would be much appreciated. Any tips on the rear Flexi seal likewise! :)


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Splitting the join: punch the roll pin out with a suitable sized punch (old chopped-off screwdriver) and the shaft should disconnect. Unbolting the shifter housing will move the rear part of the shaft out of the way.

Rear seal/output shaft seal (if that's what you mean by flex seal): there are tools to enable you to do it in-chassis but seeing as you have the box out, it's much easier to remove 6 or so bolts and split the extension housing from the box. This will possibly damage the gasket between them so maybe source a new one before doing it. These boxes are notorious for leaking from both there and the selector rail seal. I love these boxes but oil leaks are what I don't miss about them.

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There’ll be a roll pin in a hole that goes through both half’s of the selector shaft, knock it out with a pin punch.

go buy a casket kit for a single rail and change all the gaskets while your at it.

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There’ll be a roll pin in a hole that goes through both half’s of the selector shaft, knock it out with a pin punch.

go buy a casket kit for a single rail and change all the gaskets while your at it.

I was going to suggest that but wasn't sure on advising to do the top cover as it's critical that you line up the shift spool with the guide slot on the cover without damaging it when re-installing. If that's within one's capabilities, then I say go for it.

 

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The shift spool being the ‘round thing’ around the shifter shaft and the guide being the slot on the top cover. Using words I can understand () you have to get the round thing on the shifter shaft to sit in the guide on the top cover yes?


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