1600 crossflow with 1500 pre-crossflow head

[dr_ed]

I have been doing a bit of research regarding engines to put in the Cortina. An opportunity has come up that will mean I will bring back the car to that of its period and putting the ford kent engine in it, (don't worry I will have a Cortina with 4age turbo in it one day just wont be this one at this stage).

I have been considering all my options, I want to stick with the pre-crossflow head as I have one of these in the garage, also it keeps the car looking "standard" for when I go for warrants and to get the car back through the NZ re vin process and not to cause too many unwanted hassles. I want this to be a usable peppy street car that will see a bit of hill climb / Targa type use, maybe give it a go down the strip once or twice.

I have a couple of options for this all utilizing the 1600 cross flow block and have yet to consult with my engine builder who has done many kent engines, so this is all "theory knowledge", but want to get a general consensus of direction to go. I don't want to spend ridiculous amounts of $$ on a full blown race build, but don't mind opening my wallet a little. Ideally I would like option 1 from below (if it is going to work)

Option 1: 1600 711M Block bored to 82.48 mm with 1300cc pistons to match and the pre crossflow head, (small amount of port / polish), I know this has been done with the standard crossflow engine and raises the compression nicely to about 10.3. I was wondering how this would be with the 1500 pre-crossflow Cortina head, as the head is a recessed pocket valve type?

Option 2: 1600 cross-flow block as above, 1600 pistons, small overbore to raise compression to 1658, 1500 head.

Option 3: build a engine similar / same to the Mongrel pre-crossflow build described here here, this seems like a little more work than the above options.

No matter what combination I use from above I will probably go for a cam similar to cosworth specs, or the kent cams 234 or 244, (244 may be a bit excessive) and may have to fly cut pistons, unless somebody has a better idea / recommendation.

Hope that wasn't too much fluff and make sense, any comments, recommendations or options I am willing to consider.

[UncleJake]

I built a motor for a friend a few years back but I can't quite remember all the details

We took a 1600 block and decked it by 6mm, fitted oversize 1500 pistons to the 1600 rods (you need to relieve the piston skirt a bit from memory) and poked a 1500 head on it. We used 1500 pushrods. It went like hell but suffered a bit of pre-detonation on ULP and used to pump a bit of oil out of the sump

A bigger sump and slightly lower C/R would have helped.

I see no advantage in using the heavy 1600 or 1300 pistons if you can source the 1500cc flat top ones. Your C/R will be determined by how much you deck the block. We went too far

[dr_ed]

Thanks unclejake, that makes a lot of sense and sounds like a viable option, and a known one! plus cuts down on piston weight! I have seen your build that's impressive!

Any other options to consider while we are at it?!

[europatek]

I'vehad several engines in this configuration. I used a 1600 block and crank. I bored the block to either 83 or 85 and used Datsun pistons which have a slight dish. I mated these to Datsun
6cyl rods, L24 to be exact. You need to spend some time releiving the block so the big end clears. The pistons need a slight deck to make them flush with the block, whilst leaving about half of the dish. I fitted to this a well ported and flowed 1500 head with big valves, 11:1 comp, 40/80 cam and twin webers. The engines went really well. Chassis dyno figures at the time were between 80 and 85KW at the wheels. I used a well known workshop in Melbourne, Tate Automotive, and Ian was very impressed with the results.

[220 GT]

Hello

That is the exact build of my motor

We went 85mm Bore in a 711mm block L24 rods with MK1 GT pre cross flow head (we had problem otaining a decent set of valves to suit the head i ended up getting a set of Stainless Steel valves made costed me a packet)

There is heaps of Comp

I am running a single 45 Side draft webber

I am pretty happy with result

Cheers Mark

[europatek]

Hey Mark, glad to hear you are happy with the results. It's a good combination. To get the best out of it you'll need a well flowed head. A GT head is a moot point once the flowing is done
as you need to remove lots of metal, ie any trace that it was a GT head. I used a std 1500 head with shortened Gemini valves, 42 and 36 mm I think. I took 0.120" off the head
to get the compression. I used twin 40's and 42's and the standard GT extractor which I found worked better that the 4 into 1 set I had. I've attached a photo of another 1500 head that I have done, this time for a tuned 1500. It gives an idea of the work/shapes involved.

[dr_ed]

I have read a lot about datsun stuff in these engines, Is it only the crank which needs lots of machining? or is it the whole caboodle rods and pistons,? Does the L24 rods fit on the standard 1600 crank OK without too much machining!?

Cheers

Ed

[jewels]

theres also a how to and PDF to download in the 'how to area'

go HERE

[dr_ed]

thanks Jewels, I have seen that PDF its got some very good information, unfortunately it appears it is mainly for using the datsun crank which would be awesome but more likely a few more $$ involved with machining than I want to spend atm, but if datsun rods and pistons are a "bolt on" or things need a little bit of relieving i.e. piston skirt or block etc. I can do that with the machines I have access too. If that makes sense. I guess its time I chat to engine builder see what he thinks!

thanks

Ed

[mk1 rob]

Hi guy, just wanted to now if the rod bearings for the 1600 crack, l24 combination are off the shelf items