Cylinder head

[Coppertop1234]

Project 2  (1978 F1) has issues with the head so we are looking for a replacement top end.


I have seen an F2 head on eBay in UK and think it would be a straight exchange?


Any advice please

Cheers

Keith Snr

[hairygit]

Project 2 is an F1? An F2 head can be made to fit, but it's a lot of hassle to keep it oiltight due to mods to the lubrication and oilways/return passages in the head, and are notorious for rapid valve/guide failiure, and very expensive to source replacement.  Far better to look for the correct head, also shared with the 750K7. I understand that earlier K heads will also fit, but you'll need to get advice from Bryan or Trigger as to what's involved

[Spitfire]

I may be wrong but if I remember correctly the F2 has domed pistons and larger volume hemispheres in the cylinder head so you will be lowering the compression, here's some info from the US site, http://forums.sohc4.net/index.php/topic,99165.msg1105940.html
There is probably more information over there.

Cheers

Dennis

[royhall]

Most definitely not the same. The F2 head is unique to the F2, bigger valves being the biggest difference. Don't think it would fit either, dowels are possibly different.

[Trigger]

+1 with Roy on the F2 head, will be a nightmare to get it right. Some of the F1's had domed pistons, but even that head is not a straight swap.

[Coppertop1234]

So the F2 head is out of the running - Thanks for info

Will the K6/7 series be a possible replacement.
Seen some in USA, but expensive when postage and customs have had there bite of the cherry

I am struggling to find a 1976 F1 in decent condition, has anyone got one they would wish to part with?

Cheers

Keith Snr

[AshimotoK0]

Not sure K7 is different. I had one but I gave it way yonks ago to someone on here.
Think the K6 would be OK though

[hairygit]

K7  will fit, the K7 used the F1 engine, but fitted with those awful carbs similar to the F2

[captaink]

Reference  the comment valve guide failure on f2s. As a point of interest, I have just ordered new cast iron APE f2 valve guides in the UK for under £70 the set. In stock.
Found a supplier...Suzuki performance spares. They have a website and are Honda also.

[bytio]

I can see the bronze guides there, but not the cast iron ones,  do you have a link?

[captaink]

i think the guys name is Nick. They may not be listed but he has them,
I confirmed there f2, he seems quite knowledgable .
The bigger f2 valves I have ordered from him are coming from the USA and are kibblewhite and will be about 2-3 weeks although double the cost of other valves.
Springs are also in stock.

I will most likely order the big bore kit from him at £ 495 as it's also in stock

[royhall]

Got my F2 Kibblewhite valves from CycleX in the States. Good price and fast delivery. I'm told the original guides are a good replacement as they were changed later on for harder items that wear less. As they kept the same part number, I believe it's called a delta change part?

Sent from my GT-I9305 using Tapatalk

[Coppertop1234]

Found this one in USA seems to be correct 1 for a 1977 CB750 F1 ?

http://www.ebay.co.uk/itm/77-HONDA-CB750-SOHC-CB-750-K-HM272B-ENGINE-CYLINDER-HEAD-/231635611814?hash=item35ee8ef0a6

[hairygit]

Ouch on the postage,vand don't forget george osborne will want his cut (whatever import duty it attracts, plus 20% v.a.t. on the purchase price, postage and import duty!) plus royal snail adding at least £12.00 for acting as tax collectors!

[Coppertop1234]

Found 1 in Uk but its from a 73 so early K series unsure if it would be compatible or http://www.ebay.co.uk/itm/321466019903?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Better price but will it fit a 77 F1?