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Post by dickie on Nov 28, 2023 17:28:16 GMT
I bought one as part of the parts pile two years or more ago.
My engine should be good on that for a few years !!
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Post by dadbif on Nov 28, 2023 18:23:43 GMT
NC serpentine belt idler pulley is a handy size.
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Post by dickie on Nov 30, 2023 16:50:26 GMT
The original BP design is "non interference" in that if you bust a timing belt, if one of the valves stops moving at max full lift, the piston just cannot go up high enough to reach it. A combination of higher lift cams, higher compression piston, and a shaved head may have changed that. If this is the case, and you know about it, it may be worth changing the cam belt a bit more frequently, especially if you have fitted super strong valve springs, and you plan to give it a bit of a rev. Hi I am aware of all this. The current engine is already interference with Piper 285 cams and a decent head skim. I will need to take more off the head to bring the CR back up. I dont see having an Interference Engine as a problem ( I am often interfering with engines )
I have some nice soft modelling clay to play with when I check it all out. I have know of one guy in the states that has taken 130 thou from a Mk2 head !!
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Post by warpspeed on Nov 30, 2023 22:41:44 GMT
I dont see having an Interference Engine as a problem.
No its never a problem....until it is. |
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Post by thruxton on Dec 1, 2023 8:24:39 GMT
Dickie.
You can’t leave me hanging there…..
Even though I’m into NC’s now.
The guy who shaved the head 130 thou.
Please tell more.
Was it a standard engine apart from that and he was experimenting or was there more to it?
Anyway I’m watching your build with a lot of interest.
Good luck with it, please keep telling us all how it’s going.
Regards.
Rich.
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Post by dickie on Dec 1, 2023 16:47:25 GMT
If you guys look up Garage Quinn,or The slip angle. There is a lot of information on what is possible to do. This was the inspiration for the engine currently in the car before I went daft. link to his utube. www.youtube.com/channel/UCbaOnIKslLDEdvYwEx-KGtw |
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Post by dickie on Dec 1, 2023 16:49:28 GMT
I dont see having an Interference Engine as a problem.
No its never a problem....until it is. Loads of modern cars have interference engines my volvo v70 diesel is one !! |
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Post by Zed. on Dec 1, 2023 18:55:45 GMT
No its never a problem....until it is. Loads of modern cars have interference engines my volvo v70 diesel is one !! why do people worry about valve / piston clashes? my Vauxhall engine is an ' interference engine' but its also got 12.5mm lift cams  but one stone in the cambelt &  Rich. |
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Post by warpspeed on Dec 1, 2023 21:38:00 GMT
I bought a complete B M W engine minus the cylinder head for very little money from a high class inner city auto repairer.
This guy only services top end European crap, Porsche, Ferrari, B M W, Lambo, Mercedes etc for the wealthy inner city Yuppies.
Some poor bugger had his B M W Z3 blow up and totally demolish the cylinder head when a plastic chain guide let go.
The mechanic could not source just a new low mileage head for the customer, had to buy a whole engine.
The customer got the almost new cylinder head, I bought the rest. This was an almost brand new engine I could tell by the zero wear clutch and by the original factory hone marks that went up right to the top of every bore.
Very strangely, there is not a single mark on any of the piston tops.
I only know what I was told, and never did see the supposedly wiped out cylinder head. So its all a bit of a mystery.
Maybe the customer was being ripped, I do not know. Anyhow, it was a great win for me.
These Bimmer four banger engines have a tiny combustion chamber, and 10cc dished pistons, and still have a 10.5 compression ratio. All very odd.
If the cams ever stop turning, its total carnage.......
Yes, a lot of factory engines are like that these days. Maybe its planned obsolescence.
I plan to use that engine with a BP-4W cylinder head that bolts straight on.
Without doing anything else I end up with 8.4 compression, and non interference.
Perfect for a high boost supercharger.
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Post by Whistler on Dec 2, 2023 18:27:42 GMT
I plan to use that engine with a BP-4W cylinder head that bolts straight on. Without doing anything else I end up with 8.4 compression, and non interference. Perfect for a high boost supercharger. The head really bolts straight up and water chambers dowels & bolts line up? I take it the engine mounts are different? |
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Post by dickie on Dec 2, 2023 20:16:24 GMT
Hi Folks,
Now the block is almost built I am getting my head round the Head !
I have been looking into Cometic Head Gasket sizes and the UK site is not functioning very well.
I have had a virtual trip to Cometic USA and they offer 11 Head Gasket options from 027 thou right up to 085 thou.
Which will give me enough information to work with.
My current thinking is to strip down the VVT head which came with the donor engine and take it into work and get it brutalised on one of the big CNC mills.
If I get the lads to take 135 thou off it I will then be able to CC the chambers and see what else needs to be done to piston valve pockets and check clearances
The VVT head is unlikely to be used but you never know !!!
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Post by warpspeed on Dec 2, 2023 21:30:54 GMT
I plan to use that engine with a BP-4W cylinder head that bolts straight on. Without doing anything else I end up with 8.4 compression, and non interference. Perfect for a high boost supercharger. The head really bolts straight up and water chambers dowels & bolts line up? I take it the engine mounts are different? Don't want to hijack this thread. Check out the longer conrods thread in the N/A section of FM. |
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Post by dickie on Dec 2, 2023 22:06:42 GMT
No problem to divert interest as it all adds to the general information.
What I am doing is very much off the wall and could well end up being an expensive flop !!
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Post by warpspeed on Dec 2, 2023 22:16:16 GMT
You are a real Gentleman Dickie !!
Off the wall ideas I like very much.
How about using Wills O rings ?
An engine builder fitted these to an engine I was putting together a very long time ago, and it worked great.
It will require a thin smear of silicone sealer around the water and oil passages to prevent weeping. These are excellent for resisting detonation, but require very flat surfaces to work properly. Wills rings are reusable.
I am sure this will be much more reliable than a super thin head gasket, because with a super thin gasket there is nothing there to compress or deform to create a seal.
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Post by dadbif on Dec 3, 2023 8:39:49 GMT
“Without doing anything else I end up with 8.4 compression, and non interference.
Perfect for a high boost supercharger.”
How will you control detonation?
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le sigh
Jul 15, 2023 20:03:52 GMT
le sigh
Jul 15, 2023 20:03:52 GMT