Tuesday 24 October 2017

Engine - Pt 9

OK, time to update where I am with the engine build.

Rocker Cover Spacers and Gaskets
Having taken a little time out to build the engine frame it is nice to getting back on with the engine build.

From the outset it was painfully obvious that I was going to need a couple of spacer plates for the rocker covers. These were made for me by Brown & Hawthorn on Coventry who had them Laser cut to my .dxf file and a lovely they are too. All they needed was polishing and lacquering to maintain the shine.

After polishing they were ready to be assembled. This took a little thought as once both parts have the Gasgacinch applied you only have one opportunity to get this right. I did a couple of dry runs to see how the gaskets could be 'adjusted' to make them fit correctly. After this I applied the adhesive and waited! I raided my wife's cupboards to find the grease proof paper to use as a barrier between the two parts as I gently aligned and fixed the parts together. This made it very much easier and I didn't have to panic as the parts only stuck where I wanted them to.

Parts with the Gasgacinch applied
Grease proof separation layer.
Completed spacers with gaskets fitted.
These were then left pressed overnight to allow the Gasgacinch to fully cure.

Inlet Manifold
Next I decided to get the inlet manifold fitted. I must apologise as I haven't got too many photos doing this as I got a bit engrossed in what I was doing whilst applying sealer and the like.

I carefully trimmed the inlet to head gaskets and made sure I could get them where I wanted making sure that all ports were clear of gasket and both gaskets were sitting exactly where they should be. When in the correct place I put tape (good old Frog tape) along the top of both to protect areas that I didn't want sealant to show and also as an alignment aid to get them back in the correct position. Also at the same time I masked all other areas I wanted to keep clean as well.


I applied Gasgacinch (meant to say. That's really smelly stuff but it smells really good though?) to the gasket faces and the cylinder head surfaces and allowed to dry for at least 5 minutes as recommended. (Doesn't 5 minutes take a long time when you are waiting for it to pass!)

Here's where I forgot all the photos!!

I carefully positioned each head gasket in position and pressed firmly down to bed it in. Felpro advise you to fit the inlet manifold at this stage with just a couple of screws to aid in holding the gaskets in position whilst the adhesive cures so I did, gently overnight.

Next day I carefully removed the inlet manifold and removed all of the masking tape. It would have been better if I had removed it from above the gasket whilst the adhesive was still wet!

Now I had to fit the 2 'China wall' cork gaskets. These are renowned for moving on assembly of generally leaking like a sieve. Both of which are really bad. In the Felpro set I used the cork gaskets are self adhesive. You just have to make sure that all surfaces are clean and oil free. I cleaned all surface with brake and clutch cleaner as this is a great cleaner/de-greaser.

Each cork gasket needed to be trimmed a little to make them fit correctly. As advised I then applied an 1/8" bead of high temp silicone in each of the 4 corners or valley areas and then carefully fitted each gasket. When they were well and truly stuck down I ran a 1/8" bead of silicone along the top of both making sure that again the corners where the heads and block meet have plenty of silicone. Then I placed the inlet manifold in position torquing down all bolts to the specified torque in the order specified in the book that I am using as my guide. I've probably mentioned it before but the book is by Tom Monroe and is titled "How to rebuild Small-Block Ford Engines". Great book it is too.

So here is the finished article, well inlet manifold fitted with all masking removed, the excess silicone removed and the gaskets trimmed to shape to suit the manifold.



Setting TDC
Now I needed to set the engine to TDC so I could fit the timing pointer and eventually the distributor (although that will be a little later).

I listened to several videos on YouTube to get my mind sorted as I didn't want it 180° out. I decided to use a piston stop to find the exact TDC so a little while ago I purchased one from Summit. When it arrived it was very different to the advertised photo so they gave me a refund. Anyhow I had no choice but to use it but was still very unhappy with the screw thread that the piston would be banging into on full travel so I modified it.

As supplied by Summit
Modified with a nice polished domed end
I rotated the engine (clockwise is the normal rotation for SBF's) until it was just before TDC'ish (and slightly lower than the stop would screw in to) and then screwed the piston stop into position. Next I added some tape to the outside of the damper so I could mark the extreme positions of travel. Before I could make the marks I needed a pointer so I fabricated one out of a bit of piano wire and screwed in into position.

Pointer and screw to secure it
I then very carefully rotated the engine until it just touched the stop and made my first mark on the tape. I then rotated the engine anti-clockwise until it again touched the stop and made another mark.

The midway point between these 2 marks it exact TDC (well I hope it is!) so I very carefully measured the distance, divided it by 2 and, after removing the piston stop rotated the engine clockwise until the new central mark aligned exactly with the pointer. So the engine is now set to TDC. All I have to do now is remove the pointer and tape and fix the timing pointer.

Aligned to centre mark
Timing pointer added


The timing pointer only needed a little filing of the holes to get it to fit exactly where I wanted it. I have added a white line to the pointer too to make it a little more prominent.

Thats all for now but hopefully more later this week.


Sunday 22 October 2017

Engine Frame

The time is approaching (be it rather slowly I must admit!) for the need of an engine frame for when I am able to take the completed engine across to Peter Knight Racing, Daventry to be setup and run in and certified.

So then, onto frame construction. What I would say is that it is essential to very carefully measure everything twice before you cut and especially before you weld. Do not assume that the engine mounts are symmetrical from side to side on the engine block! More on that later!

I decided to build my frame out of 30mmx30mmx3mm section steel so after measuring and calculating what I needed I bought a couple of 3m lengths of tube and some 30mmx8mm plates for the actual mounts. (As I was making this myself it meant that I had to purchase a nice new chop saw. Another great addition to the workshop!). This was then all cut to the appropriate sizes, de-burred and thoroughly cleaned as when the steel arrived it was covered in something like a graphite paste and was very messy to work with but it stopped it rusting before I used it though. As I normally do when making something I model it all out on CAD (day job!) just to make sure everything fits (or at least should do if you measure it correctly in the first place).

Nice new chop saw!
CAD of frame.
All parts cut to length
De-burred and ready to weld.

Now there was just one issue! I forgot to just tack weld the four mount plates before checking whether it fitted as expected. As you can guess it didn't!!!! I had not realised that the 2 pairs of mount holes were offset from one side to the other. Fortunately it was a simple task (ignoring the cutting and re-welding) to sort out and I am pleased to say that all is now OK. No harm done just another wasted hour or so.

Welded and painted with POR15.

Just now need to get that engine completed.


Saturday 22 July 2017

Engine - Pt 8

It has been quite a while since my last post. So after being rather busy recently I have finally had the opportunity to sort out measuring the length of pushrods I need for my particular engine.

I ordered these from Peter Knight racing and they arrived about weeks or or 2 later.


Now comes the task of fitting and adjusting the valve train.

First job was to clean all the pushrods making sure that they are nice and clean particularly inside as oil flows through these for lube for the rockers etc..

One thing I did notice was that there are a number of different designations on the rods. I am assuming that this is OK but will call and check just to be certain.


So... After cleaning each pushrod I carefully applied a little Graphogen to each end of the rods making sure that the holes are clear and then carefully placed then in their respective positions, all 16 of them.


After this I prepared the adjuster's and locking screws before getting the lifters out of their oil bath. I fully unscrewed the locking screws to leave just a thread or so engaged so I could clearly see which ones were still un-locked. Just had to make sure that the locking screw was not interferring with the adjusting process.


Rockers in oil bath. Been soaking for quite some time.

I then cleaned the excess oil off of the lifters and coated each of the rollers with Graphogen. Also the top of each valve was given a coating of Graphogen too.

With and without Graphogen on the rollers
Pre adjustment.
There's alot of information on the web regarding how to adjust/pre-load the valves (some good and some not so good). In the end (2nd time of course!) I very carefully followed the information given with my Compcams camshaft, which I should have done first. Still, all now seems to be good now.

One last thing. I thought I'd have a check/look at fitting the rocker covers but as I had suspected there is a height issue due to me changing to roller rockers. I knew when I purchased the rocker covers that they may not be tall enough so have already purchased 2 sets of gaskets, just in case. All I need are the spacer plates. The parts that touch rocker cover baffles are the adjuster nuts. I did also rotate the engine to make sure the rockers were at max lift but these are well below the adjuster nuts. You can just make out the 2 areas that touch in the photo below. It is quite tricky to measure the interference so I used the gaskets I already had. With 2 gaskets there was a little interference but with 3 there was clearance. The gaskets are 4mm thick each. I'll get 6mm thick spacer plates laser cut and polish the edges. When I fit the covers, spacer plates and gaskets I'll use some suitable liquid gasket to give a little peace of mind as well.



Not quite what I had hoped for but it will be fine with the spacer plates and a gasket either side.

Thats all for now until the spacers are made.



Wheels 1

After alot of discussion on the UK Cobra Club forum I decided to go for Vintage Wheels in the US.

There was alot  of discussion about either 407 or 427 styles. Both look really good.

407 Style

427 Style
Eventually I decided to go for 18" 427's as I simply prefer the look of these. 407's are great but actually a little 'too' smooth for me.

The main concern highlighted to me by Bob was that due to the high offest values on the front wheels the 427 style is slightly outset from the rim. For me this is not a problem.

Bob Lacey at Vintage was really helpful and a great bloke to deal with. I can't recommend him or his company highly enough. The wheels are a work of art and licensed by Shelby too.

Tyre/Rim sizes as follows:-

Front - Rim 8" wide, tyres 225/45 R18 Y (91) Continental Sport Contact 5 SSR
Rear - Rim 9.5" wide, tyres 255/40 R18 Y (95) Continental Sport Contact 5 SSR

At the time of order I also purchase chrome wheels nuts, spinners and the wheel nut covers.

After ordering on the 22nd March they finally arrived on 2nd May and I must say that I am really delighted with them. All fits well on the XJ40 hubs so that is a relief too.