engine builders cast your eye over my xflow rebuild please

[Bear family]

Hi. I am building a 1700 xflow after my other engine went bang. Now I’m no professional but I like to think I have the basics covered. I am going to post pictures here of the process and welcome your opinions on where I could be doing something differently.
I appreciate this won’t be as exciting as a cosworth but for me it will be!
Some of below is coming off the old engine but I have spent £1000 on new parts

711m block acid cleaned and re bored
+110 pistons with deeper valve pockets
crank polished
244 cam
standard 1600 conrods
big valve head
duplex chain
steel rocker gear
high capacity oil pump
twin 40s
accuspark coil and dizzy

couple of questions to start with.
I am using Lucas engine assembly line. Any good?
Thrust bearings the correct way around?
i have lubed the back of main bearings. Is that good practice?
Do use assembly lube on main cap bolt threads?

[Erikmex]

Thrust bearings are on the wrong way around, the slots should be to the crankshaft side for lubrication against the rotating face, no need to lubricate the rear of the shells but wont do any harm, just need ot make sure the oil holes line up and the locking tabs are in their slots.

[fatboy slim]

Lube all threads, clean out all threads with a tap or slotted old bolt, clean all oil galleries with pipe cleaners, get some HD rod bolts for an upgrade(no need for arp at that spec)

[Dyno]

Thrust bearings are on the wrong way around, the slots should be to the crankshaft side for lubrication against the rotating face, no need to lubricate the rear of the shells but wont do any harm, just need ot make sure the oil holes line up and the locking tabs are in their slots.

VERY painful if you discover this after running, it takes the crank in a short time. I always have to triple check myself because it is so easy to fit wrong.

[Bear family]

Thank you. I shall turn the thrust bearings around. The oil galleries have all been cleaned out by the engine shop that supplied the block and did machine work.
I will have a look for hd rod bolts. Need to get the rods off old pistons next and give them a clean before installing the pistons.
i think my next big problem will be timing up the cam but I’ll post more pictures as come to that

[fatboy slim]

I'd still run a pipe cleaner through them, you'd be surprised how stubborn old oil and shit is.

[wildo105e]

If you have original cam sprocket use that initially and it will get you on the right teeth etc, then change to the adjustable one for fine tuning. Unless your adjustable ones have marks but check them.

Pistons are easy on a x-flow. just double check you get them the right way round.

double check everything.

[HonkyWhiteTrash]

Thank you. I shall turn the thrust bearings around. The oil galleries have all been cleaned out by the engine shop that supplied the block and did machine work.
I will have a look for hd rod bolts. Need to get the rods off old pistons next and give them a clean before installing the pistons.
i think my next big problem will be timing up the cam but I’ll post more pictures as come to that

Even if you have absolute trust they cleaned the galleries out, that doesn't stop anything getting in them before you assemble it, or everything coming out that was supposed to. I get my blocks cleaned by the mahine shop and then I clean them myself to make sure.
Re HD rod bolts do not buy Burtonpower's own brand - they have had a batch that stretch beyond belief. There's nothing wrong with original xflow rod bolts (V rated), but you could also use original Lotus Twincam rod bolts as they are aircraft grade (X rated). If you are convinced you want new HD bolts just buy ARP (and then check they clear your oil pickup pipe and sump once installed - some engines are OK, some not).

Those +110 pistons may not come with pockets deep enough despite what is advertised - I used some and they were nowhere near deep enough as the block was decked a fair bit, and the valves were sitting very proud of the head (which is better for flow). Cam was also a 244.
Make sure you check there is enough clearance and don't trust anyone when they say "they're good to go".

[Graham]

VERY painful if you discover this after running, it takes the crank in a short time. I always have to triple check myself because it is so easy to fit wrong.

yup never done it myself, but ive seen it so many times i am paranoid about doing it myself

[Bear family]

I have arp bolts for rods from my scrap engine that I can use. As mentioned here, probably no need for them but if I have them and clear the pick up pipe then worth using?

ive corrected thrust washers and just checking oilways are clear

[wildo105e]

Make sure you check there is enough clearance and don't trust anyone when they say "they're good to go".

definately

[Bear family]

I’ve just checked length of arp bolts out of the Williams 5.23 rods and they come up 5mm shorter than the standard bolts. That’s a good few less threads gripping the rod cap?

[Erikmex]

Theres no such thing as X rated bolts for aircraft, aircraft grade bolts that are lighter and have the normal 40% increase in yeild strength have their own thread form - UNJ, i hear people talking aircraft grade all time!

[Erikmex]

You have to watch the shoulders also, making sure they fit correctly, ive seen so many ovality issues with conrods due to wrong bolts being fitted. Buy the correct bolts.

[fatboy slim]

I’ve just checked length of arp bolts out of the Williams 5.23 rods and they come up 5mm shorter than the standard bolts. That’s a good few less threads gripping the rod cap?

My old 1660 x/flow failed on its last event before lifting the rods, the reason, turns out the b/e bolts were shorter than they should have been and pulled out of the thread. As tesco say every little helps, especially at 9.5k

[Bear family]

Thank you for everyone’s input upto now. Here is where I’m at for moment.

Crank in and thrust bearings correct way around
main bearings are in and caps torqued to 60ftlbs
cam followers and cam in
oil galleries checked and are spotless
con rods connected to pistons with 2737e front facing front of block ?
pistons in and connected to crank with standard bolts for now





just thought though, I’m going to have to take pistons back out because I never took the rings off to check gaps in the bores
I’m going to look at rod bolts later as I won’t be using the shorter arp ones I have.

[HonkyWhiteTrash]

Theres no such thing as X rated bolts for aircraft, aircraft grade bolts that are lighter and have the normal 40% increase in yeild strength have their own thread form - UNJ, i hear people talking aircraft grade all time!

As far as I know, aircraft grade bolts do not exclusively use UNJ, and X rated bolts (tensile strength of 150,000 psi/75 tonnes/sq in) sit at the higher end of the description for the grade - as I understand it anything from 125,000 - 160,000 psi is classed as aircraft grade.

[Erikmex]

They’re not called x rated, that’s movies, the higher yield strength ones are UNJ, I work with them daily

[HonkyWhiteTrash]

So what do you call a bolt that's marked with an "X"?

[Erikmex]

-X- like that or + means AN Standrard steel bolt (on aircraft grade) but X on all bolts like ASTM specification is just a manufacturers ID mark, you'l see X on lots of grades of bolts, grade / material spec is usually a letter and a number, like on an ARP conrod bolt you'll see the likes of L19 which is ~ 220k psi, much higher tensile strength than most aircraft grade bolts.

[katana]

My old 1660 x/flow failed on its last event before lifting the rods,

Isn't that when something is supposed to fail - the cool down lap after the race LOL! Your engine obviously knew it was in for surgery!

[fatboy slim]

Isn't that when something is supposed to fail - the cool down lap after the race LOL! Your engine obviously knew it was in for surgery!

Think it was beginners luck, as I've got better with all the following motors. The bolt didn't break and the rod was fine, just shows how much rests on those little fine threads

[Bear family]

So for now I have decided to torque up the standard rod bolts. Does anyone know a supplier of the twin cam bolts other than burton?
Gasket set came yesterday. I went for the more expensive option.
Checked ring gaps and they are at 0.25mm
I could do with a bit of help on order of next bit. I have bottom end built up now minus sump and timing cover. I presume that before timing cover can go on, I need to work out cc of pistons, tdc height and calculate gasket thickness for correct compression ratio. Followed by a trial fit of head to do timing and check clearances?

[Bear family]

I have had a go at doing the timing today for crankshaft and camshaft.
if someone could let me know if I have done it correctly
Found tdc on number 1 piston then set a datum and put timing disc on 0 degrees.
I have then rotated crank until datum hit 103 degrees atdc.
following this I rotated camshaft until no1 inlet valve hit full lift.
I then connected chain and sprockets at those positions.

correct?

[Graham]

how did you measure full lift?

[Bear family]

Measured with callipers the inlet valve cap off a point on head with valve closed then when it got to fully open. I rocked back and forth to try find the middle point as best I could between hitting full lift and starting to close again?

[Graham]

sorry but thats nothing like accurate enough, you need to be able to measure with an accuracy of one ten thousandths of an inch, 0.001" or 0.01 mm so you could be miles out! you need to do it with a DTI both to establish true TDC and full ift on the cam, there's a useful guide on burton site

https://www.burtonpower.com/tuning-g...ng-timing.html

[Graham]

sorry but thats nothing like accurate enough, you need to be able to measure with an accuracy of one ten thousandths of an inch, 0.001" or 0.01 mm so you could be miles out! you need to do it with a DTI both to establish true TDC and full ift on the cam, there's a useful guide on burton site

https://www.burtonpower.com/tuning-g...ng-timing.html

[Bear family]

I’ll have a look now for a dti to add to the tool kit then. I have seen them used before.
I have just checked the valve clearance with play dough and I have 1.21mm between valve and piston with a 1.3mm gasket.
I shall get a dti and do all those checks again.
Thanks graham

[Bear family]

Just realised I have a dial gauge with my bore gauge, so I’ll just need to get myself a dti stand.

[katana]

For establishing TDC I prefer to fit the degree wheel first with a pointer approximately at 0 deg. TDC and then use a positive stop tool - use an old, gutted spark plug with a thin rod welded in that forms the stop. Wind engine over till it reaches the stop and note the degree reading, then wind it backwards till it stops again and record the angle. Add them together and divide by two and that is where TDC is. Turn the crank to that number and without moving the degree wheel position adjust the pointer to be at 0 deg. / TDC. If you know the cam spec's (opening angle / closing angle / max lift degrees, then you and see when these are occurring against your accurate degree wheel and adjust as required. One thing to be careful with is the valve/s hitting the positive stop due to its position between the valves - it works much easier with 4V engines and the plug being central between them. Can be done with a dial gauge on the piston if head is off but there is a dwell period of approx. 5-10 degrees at TDC so note degree angles when gauge measures 0.050" or 2mm either side of TDC, then its add and divide as above.
Its a lot of words but once you do it, it'll start making sense.

[HonkyWhiteTrash]

-X- like that or + means AN Standrard steel bolt (on aircraft grade) but X on all bolts like ASTM specification is just a manufacturers ID mark, you'l see X on lots of grades of bolts, grade / material spec is usually a letter and a number, like on an ARP conrod bolt you'll see the likes of L19 which is ~ 220k psi, much higher tensile strength than most aircraft grade bolts.

I had some NAS (National Aerospace Standards) bolts recently and they were 3/8" UNF and not UNJ. Seems to be that there isn't a hard and fast rule that UNJ is the only thread available. Slightly confusing to say the least.

[Bear family]

I decided to measure using a dial gauge. My stand turned up today so I have spent last couple of hours in garage.
Graham was right that my initial way of measuring wasn’t close enough. I was about 3 degrees out.
followed the burton power guide to a tee and have managed to get to within 1/2 degree. Double and triple checked by taking a measurement before and after tdc/max lift on dti, adding 2 degree angles on wheel at those points and dividing by 2 to tell me where exact max points were.

now got to double check with play dough and head can then go on with a new cometic 1.3mm gasket.

[Erikmex]

No they’re not all UNJ but the high strength ones are, most normal thread aircraft grade bolts are weaker as they are designed for weight saving. If you think those threads are confusing you should see some of the oil & drilling industry thread types, variations on acme that would blow your mind

[Bear family]

I have my head sorted now with new valve springs and caps from john Wilcox.
My next problem is getting the head gasket to stay lined up while fitting. I bought dowels that locate in the block and lines gasket up but the head doesn't take the dowel. Holes too small.

How people keep there's lined up and locating the head to its correct position?

[Graham]

best way is with old head bolts, cut the tops of them, saw a slot in the end so you can unscrew them with a screw driver, then screw them into the block, fit the gasket drop the head on and replace with the actual head bolts your going to use

[Bear family]

Having problems now. Head came back with new guides. Built engine up, back in car and got everything connected.
Turned engine over without sparks to get oil pressure.
On starting the car after a few seconds, oil was jetting out the side of oil filter seal.
Cleaned up, made sure seating was correct and same again only this time it had emptied most the cars oil from somewhere else on rear of engine
Anyone got any idea as getting really fed up now.
Cheers

[Bear family]

[Bear family]

Could it be wrong oil filter?
Removed oil separator, pipe from new elbow to catch tank, catch tank to oil cap on rocker.
I lost from what I can see about half the cars oil in about 20 seconds of running.. Mostly from very badly fitting rocker cover, hence the new one with new gasket and from oil seal on filter popping out.

[fatboy slim]

If its come out of the rear it can only be the oil gallery plug. If it was a dodgy seal or gasket it wouldn't be under as much pressure and so would be a lot slower leak. Oil filter seals are sometimes fiddly to fit in the groove