40 replies to this topic

[Jarvey]

I am so glad I asked this question! Your knowledge is invaluable thank you so much!

You've just clarified my argument for more power! More power means the engine isn't working as hard when plodding around. There are 2 big hills on my way to work that when left in 4th the car bogs down and slows to 60mph flat out and the engine is obviously struggling and working double time.

I must admit I do like the idea of forced induction at a later date, but think the 7 Port is a better first step. Turbo later 😁

Ok so 3.1 FD going by what you've said before. Are you running SC gears? Or the standard helicals? I need to rebuild the box anyways as I've got the dreaded 2nd gear crunch!

[Northernpower]

Ok so 3.1 FD going by what you've said before. Are you running SC gears? Or the standard helicals? I need to rebuild the box anyways as I've got the dreaded 2nd gear crunch!

I had to make a decision on how to allocate the budget when I was building the power train up. In an ideal world I would have gone for a close ratio gear set but as I was not using this one for competition I decided to go with the standard helical gears and a cross pin diff. Now the engine is built , I've found the torque it develops over such a wide rev range compensates for the lack of the close ratio gear set and whilst it not perfect its a good compromise. I've no way of measuring the torque steer but I'm convinced its less with the cross pin diff; I've spoken to others who also think the torque steer reduces with the cross pin fitted but as I've said I have no way of proving or measuring it.

 

The only mistake I made was to fit straight cut drops. I since changed these back to helicals.

[Jarvey]

Yup X pin diff is definitely on my list.

 

Guessworks now sell a close ratio helical gearset which I like the idea of ... but not sure, I think need to heckle them on the blower me thinks.

 

Also, follow my brain powers here ... I am going 1380cc which means buying new pistons, ooo ... you can get piston and conrod sets, might as well replace them too ( do it proper like ) , so might as well get short height pistons with 86mm stroke rods ... THATS A BINGO! 1460cc FUN! No?

 

Can the SC 7 port head be ported to get the CR down? I know the MED 7 port heads have been run @ 1460 ... Obviously big dish pistons are required, but with a short height I'm guessing you cant go mental.

[mini13]

It's the crank that makes it 1460 not the rods

[Turbo Phil]

 
Can the SC 7 port head be ported to get the CR down? I know the MED 7 port heads have been run @ 1460 ... Obviously big dish pistons are required, but with a short height I'm guessing you cant go mental.

Yes. Here's how I did the chambers on my SC 7port head.

[mini13]

Phil is probably the best person to say how many cc you can get in the head, I'm guessing you would need 18cc pistons, I know je used to do short deck height 18s not sure if they were available in 72.5 though but worth a look.

[Jarvey]

Mini 13 - Is it the crank??? I thought a standard crank with 6" conrods and short height pistons gave you more cc's? But I am more than likely mistaken ... Just did a quick google ... I retract my stupidity lol. That would also explain one of my other questions as to why you don't see many 1460's! Because the crank needs re-grinding.

 

TurboPhil - Nice work on the head! What cc are you running with your SC turbo set up? Id love to turbo mine at a later date!

[mini13]

we're all learning!

 

yeah for a 1460 you need either a bbillet crank, or one ground from a fresh forging to get enough meat to get the stroke. to longest you can go on a std crank is about 84mm by gringing the bigends smaller and using S rods with the 1.625" journels.

[MiniBob12]

You can "hang" the alternator from the existing lower bracket on the block and also retain the belt adjuster too. Discard the upper alt bracket altogether.

Because Rover moved the whole eng forward to package the EFI, you will not have enough room for the front mounted rad and fan.

Cutting the hole for a side mounted rad is the point of no return..................

A new fan can be mounted under the wheel arch.

[MiniBob12]

Here is a pic of my set up. It's taken a while, now nearly finished.

 

 IMG_1145.JPG   87.19K   35 downloads

Edited by MiniBob12, 28 June 2017 - 08:30 AM.

[Northernpower]

Here is a pic of my set up.

 

IMG_1145.JPG

What's the engine spec?