Thread: 2.25 head mods

G'day Michael2, [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]
your original question was loss of power recently? [img]style_emoticons/<#EMO_DIR#>/sad.gif[/img] have you got an electrical miss in the engine? if so check the plug leads into the dist. cap as they have a habit of corroding at the cap end, it's No2 on my 4cyl 2a, :? if driven hard they also tend to have the Dizzie move in the clamp and alter the timing, check also the vacuum line, as I chased a poor running, backfiring 36iv zenith fed 2.25 for a month, rebuilt the 36iv three times, :? THEN i found the pin hole in the vacc line ops: new line, problem solved, my head has been surfaced ground, and some, and is close to 8:1 and it is fitted with extractors, a 2inch exhaust system and goes prettywell I have done 140,00miles on this motor so it is starting to show it's age now, have run on unleaded (91oct) with out fitting hardened seats and the head lasted 61/2 years before killing a valve(run tappetts 1-2 thou loose) change oil filter regularly and use GOOD oil [img]style_emoticons/<#EMO_DIR#>/biggrin.gif[/img]
For cams and stuff try Ivan Tighe Engineering in Brisbane they have been in the performance cam business since I was young 8O and that's a long time ago 8O ops:

Originally posted by Michael2
hmmm

If I take my cam for a regrind, do I have to give them measurements, timing specs or anything technical, or do they figure it out themselves?

Quite right rocket we are getting a little from the question. ops:

For the cam change I just toddled in and gave them a description of what I wanted the motor to do (make it go like a sprots car) and about where I wanted power to be (3000 - 3800 roughly). They did the rest. The cam is a "stage 2" which along with the other mods makes which I've mentioned before make it toey with a nice lumpy idle. Got my cam through Watson Racing Cams in Peakhurst NSW as a regrind, Crow wanted $$$ more for the same with a little more lift. Been a while now. Can't really remember the price but about what you're suggesting.

If you've put aside $400 for this then cam and carby will be about your lot. Motors aren't cheap and machining chews up a few dollars, especially when it doesn't work out and need to get it done again.

Thanks for the input guys. I'll go and talk to some local professionals and get an idea about price for a cam regrind.

Electronically, I'm using Pirahana Electronic Ignition with Scorcher high performance leads (which have been faultness for about 7 years now!!!)and Bosch 4 pronged spark plugs. There's no shift in the dizzy, but the vaccuum line may need closer examination. I'll have a look at that tommorrow. I found some extra info about head thicknesses and pushrod lengths at http://www.cruzers.com/~twakeman/LR/FAQ_head.htm

All comments are greatly appreciated and they are especially appreciated BEFORE I spend $$$$ Thanks again, Michael

Hi Michael2 [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]
The 2.25 head should not have any thickness problems as it is a very robust and well cooled unit,unlike the 2.6 six cylinder one, ops: A major thing to be aware of, is if you skim the head a lot and the block has been skimmed to true it up at some time previous, then the head studs will bottom out in the block (this also happens with a build up of crud) it then becomes essential to fit thick flat washers under the head studs or the gasket does not pulldown correctly, ops: as the studs bottom on the block and give a false tensioner reading 8O The 7:1 motor will run quite well on standard unleaded (91 Octaine) with timing set at 6 degrees before TDC if it is a motor fitted with Anti-pollution crud the service plate will specify TDC or 3-6 after TDC, if you have removed the stuff time at 6-8 before, To check vaccuum advance unit, with cap removed detach line at dizzie if slip on type,attach a plastic tube and suck hard 8O ,you should see the dizzie baseplate move, if not Vac Advance is suspect, [img]style_emoticons/<#EMO_DIR#>/sad.gif[/img] if OK re attach the line and repeat at the carb end, if it works at the dizzie,and not at the carb then the vaccuum line is suspect, dury rig a vaccuum line and test drive, [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]

After some deliberation & price hunting :roll: I've taken some of the advice on board and got the cam reground 8O 8O [img]style_emoticons/<#EMO_DIR#>/biggrin.gif[/img] . I also got a recond 8:1 head with hardened valve seats & positive pressure seals [img]style_emoticons/<#EMO_DIR#>/biggrin.gif[/img] (it's been repaired in the past so I hope it lasts :? ). As the most I was going to be able to take my 7:1 head to was 8:1 anyway. Given it was a repaired head, I didn't throw anymore money its way and get the porting.

CAM TIMINGS FOR THOSE INTERESTED ARE :

ACTION................STANDARD................MODI FIED
inlet opens..............6 deg BTDC.............11 deg BTDC
inlet closes..............52 deg ABDC...........57 deg ABDC
exhaust opens.........34 deg BBDC...........40 deg BBDC
exhaust closes ........24 deg ATDC...........28 deg ATDC

It's booked in for Monday next week.
Then I'll need to get the exhaust done to suit the extractors.
Then get the LPG tuned (Friday at this stage)

I'll come back with some feedback on the engine mods once it's all put back together. Thanks to everyone whose had an input.

Michael

<span style="color:red"><span style="font-size:12pt;line-height:100%">BRONCHOSPASM</span></span>
No, it's nothing to do with the rodeo, and it's not a horse having an epileptic fit.
Bronchospasm is the narrowing of the small airways (bronchioles) of the lungs caused by spasming of the smooth muscle that surrounds them. Bronchospasm is a major component of asthma and other airways diseases. Often experienced as difficulty exhaling, and hence wheezing.
What has this to do with engine mods :?: Well I just cured my Land Rover of asthma :!: :!: [img]style_emoticons/<#EMO_DIR#>/biggrin.gif[/img] [img]style_emoticons/<#EMO_DIR#>/biggrin.gif[/img] [img]style_emoticons/<#EMO_DIR#>/biggrin.gif[/img]
Now it can breathe.

Hills that were 50kph in 3rd gear are now 70+ kph in 4th :!: :!: [img]style_emoticons/<#EMO_DIR#>/biggrin.gif[/img] [img]style_emoticons/<#EMO_DIR#>/biggrin.gif[/img]
And that's before even getting the thing tuned. It's booked in for a tune tomorrow, so hopefully things will improve.

Here's a summary of the asthma management.
7:1 head replaced with 8:1
extractors
2" exhaust system
cam regrind (specs as noted in previous post)

for the exercise, I was running premium unleaded (but I was using that for a couple of weeks before the mods with minimal performance gain). The LPG will be getting tuned tomorrow.

Gotta be happy about that !!! What a great result !!! [img]style_emoticons/<#EMO_DIR#>/biggrin.gif[/img]