Mud-club
Chat & Social => The Bar - General Chat => Topic started by: muddysteve on June 16, 2005, 21:45:08
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Not sure which forum to put this in but here we go
1 Are the heads from a 3.5 efi the same as a carb engine?
2 Has anyone fitted a fancy cam shaft like the ones that turn up on ebay quite often?
3 If the coolant froze in the engine and now i've got water squirting out of 2 cyinders on one side and water in the oil what do you thinks gone?
4 Can i skim the heads to get a bit more compression?
Answers on a post card
steve
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1 yes
2 dunno,all my v8s cost nought
3 its f**ked
4 not unless u want to make a low line v8 table
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1 yes
2 dunno,all my v8s cost nought
3 its f**ked
4 not unless u want to make a low line v8 table
Nicely answered!!!
My mate fitted a fancy cam. Said it made THE WORD of difference. I couldnt tell..... :shock:
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so far all my v8s have survived the pasting i have given them <runs n feels up a forest for good luck> even with bent bits (rods,& all sorts in the sump :oops: )if its spurtin water etc its time for a coffee table i think,not actually done it yet but fitting an efi cam into a carb v8 makes a difference but gott replace the plowed field crank first :lol:
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I've got a "fancy" cam in mine... had to get it ground specially :oops:
Gave my engine a big more grunt in the low-mid range.
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1. no - I believe there are "notches" for clearing the injectors. I'm looking at going over to EFi and was told i'd need to carry out this modification or change the heads.
2. I'm looking at fitting an LE1 from Lund engines (www.lundengines.com). Steve Lund certainly knows his stuff. At present I have a 3.9 cam in my 3.5 and it drops peak down the revs considerably so its quite easy to tickle it to get it moving but it has seemed to push peak horses up the range so there's more need to make that noise.
3. As V8redline said - its very broken unless as Datalas pointed out its just a core plug. Where's it coming from?
4. A little bit can be taken of the head to dress it but v8's alter the compression through piston choice and he amount of "dish" the tops have.
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1) I don't know enough aboput 3.5 heads I'm afraid!
2) Fitting a hairy cam will have an impact on horse power and power curve - whether the cams in question will give you the curve you like is a different question. Often, though, it isn't the neck-snapping type enhancement folk expect. This is mainly due to the fact that major improvements will require tweaked heads and valving etc. You won't make 250hp from just the cam. But it is usually more effective than just chipping a Hotwire EFi system.
3) If waters getting into the cylinders and the oil, I'll doubt it's a core plug (as I'm sure the plugs don't interfere with the lubrication system. It sounds scarily like a cracked block.
4) Yes, you can skim the heads for a bit more compression but..........
Check out the amount of work that Lund, JE Eng, John Eales and RPi put into making the bigger hp improvements.
Now, we do know a very nice man selling a 3.9 Efi.........don't we, Mr Web!
cheers
8)
Eeyore
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1 Are the heads from a 3.5 efi the same as a carb engine?
No, the combustion chamber is different and there is a cutout for the injectors, they also breath better. You could run them on a carb though and probably notice a difference.
2 Has anyone fitted a fancy cam shaft like the ones that turn up on ebay quite often?
If you fit a standard cam from a 3.9 to a 3.5 EFi you can get as much as 10hp, worth a thought.
3 If the coolant froze in the engine and now i've got water squirting out of 2 cyinders on one side and water in the oil what do you thinks gone?
If you're lucky a head gasket but quite possibly the block.
4 Can i skim the heads to get a bit more compression?
You can but I wouldn't advise it. You'll end up having to retard the timing and even then it'll be a problem. The cretin who had our car before us skimmed the heads, he'd got 205psi cranking pressure :shock: Now it ran well on LPG, which has an octane rating of 115 and burns slowly but to get it to run on petrol he'd retarded the timing to 2 degrees so it didn't run that well anyway, but worst of all if you ran on petrol and give it some throttle it would burn out exhaust valves in about 2 minutes :evil:
If you're going to skim the head then fit a composite gasket, they are thicker then standard but actually more reliable. I've fitted 2 and am dead happy with them 8)
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thanks for the replies chaps, much appreciated
can anyone see any issues with this plan
take of the heads from the dud efi lump, rebuild them ie tappets, valve stem seals an lap the vavles back in.
only skim them if they need it, hopefuly they wont. and then put them in my disco 3.5 on carbs
remove all the ancillaries from the dud engine and ebay them.
the thinking behind this is i've got a noisy tappet and i'm burning a little oil so hopefully overhauling the heads will cure this
Steve
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The tappets don't sit in the heads, they sit in the top of the block and can be removed without taking the heads off, as can the cam obvioulsy.
As for your plan, I'd say make sure both heads are skimed the same, you can check this because there is a witness drilled into a small square peg on the front of the D/S head and the back of the P/S, the heads being the same.
Burning oil? ours does this and rebuilding the heads didn't help unfortunatley. Whilst you've got the heads off check for the wear ridge caused by the rings. Plus unless it's a newer head then the valve stem oil seals are more of a token gesture. New valve guides might help a little but how much are you going to spend to save a little lost oil?
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you are better off replacing the heads and there is a difference between the efi and carb heads the valves are bigger on the efi ones for a start. and if you skim the heads whilst running a 3.9 cam you WILL get nicely bent pushrods as the skimming will push the rockers down harder onto the pushrods and the 3.9 camshaft having a longer duration will be attempting to push the whole lot into the pistons SO DONT skim the heads unless you want to have a bigger bill PM me if you want some pictures of the results of a mate who did this
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As an add on sometimes burnt oil may be caused by blocked breathers caused by water or condensation in the oil this in turn causes the crankcase to force oil into the combustion chamber and it will exit via the exhaust
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3.9 cam? i've not got one of these, i was planning on sticking with my existing cam shaft but just puttin gthe efi heads on my engine
i was thinking of fitting one of those fancy cams you see on ebay quite often but common sense got the better of me
Steve
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3.9 cam? i've not got one of these, i was planning on sticking with my existing cam shaft but just puttin gthe efi heads on my engine
i was thinking of fitting one of those fancy cams you see on ebay quite often but common sense got the better of me
Steve
the cams on ebay may give the same effect as a 3.9 one as all they do is alter the opening duration of the valves to help the motor breath and exhaust mor efficiently