Engine Block and Head Data - Jaguar Forums - Jaguar Enthusiasts Forum

Notices
Jaguar Engines & transmissions Discuss performance / modifications / upgrades etc here..

Engine Block and Head Data

 
  #1  
Old 02-19-2018, 05:13 PM
Member
Thread Starter
Join Date: Dec 2014
Location: London
Posts: 55
Thanked 4 Times in 4 Posts
Default Engine Block and Head Data

Folks,

I'm looking to mod an AJ27 and need to play around with the compression ratio and bore.

Does anyone have the cylinder head, deck clearance and other volume-related figures to hand?

I know it's a square 86/86 bore and stroke - I'm planning to up this to around 93ish bore and perhaps reduce compression slightly to allow a modern screw-type SC to be installed, amongst other things for my first stage mods.

Thanks in advance.
 
  #2  
Old 02-25-2018, 07:50 AM
XJR-99's Avatar
Senior Member
Join Date: Nov 2011
Location: Europe
Posts: 741
Thanked 220 Times in 167 Posts
Default

Originally Posted by ahmedalalousi View Post
Folks,

I'm looking to mod an AJ27 and need to play around with the compression ratio and bore.

Does anyone have the cylinder head, deck clearance and other volume-related figures to hand?

I know it's a square 86/86 bore and stroke - I'm planning to up this to around 93ish bore and perhaps reduce compression slightly to allow a modern screw-type SC to be installed, amongst other things for my first stage mods.

Thanks in advance.
93mm is not safe for SC engine asn specially if you have AJ27 block. Same later blocks allow up to 92mm SC and up to 93mm N/A. 4.0 safe is max 90/91mm. Depends on block castings. There is no need to lower CR.
 

Last edited by XJR-99; 02-25-2018 at 07:53 AM.
The Following User Says Thank You to XJR-99 For This Useful Post:
ahmedalalousi (02-27-2018)
  #3  
Old 02-27-2018, 01:08 AM
Member
Thread Starter
Join Date: Dec 2014
Location: London
Posts: 55
Thanked 4 Times in 4 Posts
Default

Originally Posted by XJR-99 View Post
93mm is not safe for SC engine asn specially if you have AJ27 block. Same later blocks allow up to 92mm SC and up to 93mm N/A. 4.0 safe is max 90/91mm. Depends on block castings. There is no need to lower CR.
Thanks for his XJR-99.

With a bit of care, I've known the later heads to take a 94mm bore but a good quality metal layered gasket is called for + thorough testing. That said, I am going to heed yours and other sage advice to not go beyond 92, and of course a layered steel head gasket, new valves, guides and seats.

I'm commissioning a new 416 steel alloy crank, so the next port of call is to maybe increase the stroke slightly to something like 89, so a 92/89 engine is the result. Forged pistons and their hardware will go with that, as well as new con rods.

The M112 SC is also getting a porting, bearings and pulley upgrades.

I'll keep this thread updated with results - I'm looking forward to see what sort of torque and HP numbers come out at the other end of the dyno. What I really want is to take it to 550Hp+ and some serious torque.

Thanks again.
 
  #4  
Old 03-08-2018, 08:38 PM
Tijoe's Avatar
Senior Member
Join Date: Feb 2010
Location: Kalispell, Montana
Posts: 863
Thanked 209 Times in 156 Posts
Default

There are several other engine build threads where you can find a lot of engine build details. Perhaps you have read them. I started my "High HP super build" a couple years ago and stalled out due to technical difficulties. My block is bored/sleeved to 92mm. This is the limit! Do the math. 98 bore spacing, give you 6mm max between cylinders for the heads to seal, not much for a SC engine.
I 3-D modeled the stroked engine I wanted to build and ran into a challenging and expensive problem. I wanted my engine to be balanced for 7000 rpm operation. What I found is that with 92mm pistons, standard pins/rings, combined with custom steel rods, I could not get the cross-plane fully counterbalance masses on the crank to balance unless I went with heavy metal inserts or went with custom Ti rods. Due to our 98mm bore spacing, the counter balances are narrow and are limited in OD by the walls of the block.
To some degree, increasing the stroke helps with rod weight/balancing, but you will have to run the calculations for a complete custom engine build. Don't just try to throw in a custom stroked crank, without having the rods, pistons, and masses of the flywheel and front lower crank pulley included.

At 550+ hp you can probably get away with the standard crank design, (no center counter balances, but then you better pay close attention to engine harmonics. (The count has written abut the 4.2's harmonics.)
I was designing my engine for 700+ hp, so I had to pay more attention to rod strength (added mass) and engine balance.
My limit for the stroke was 90.2 before my rods or block would have to be modified

I believe that the Arden kit claims a 92mm stroke. If you are only wanting 550hp, might be more cost effective in the long run to use their kit. (if they still offer it.)

On the other hand, good luck getting much out of the M112. If you are spending the money to build up the engine go with the KB twin screw.
 
The Following User Says Thank You to Tijoe For This Useful Post:
ahmedalalousi (03-10-2018)
  #5  
Old 03-09-2018, 12:20 AM
XJR-99's Avatar
Senior Member
Join Date: Nov 2011
Location: Europe
Posts: 741
Thanked 220 Times in 167 Posts
Default

Arden kit stroke: 95.6mm .
 
The Following User Says Thank You to XJR-99 For This Useful Post:
Panthro (03-09-2018)
  #6  
Old 03-10-2018, 05:06 AM
Member
Thread Starter
Join Date: Dec 2014
Location: London
Posts: 55
Thanked 4 Times in 4 Posts
Default

Originally Posted by Tijoe View Post
There are several other engine build threads where you can find a lot of engine build details. Perhaps you have read them. I started my "High HP super build" a couple years ago and stalled out due to technical difficulties. My block is bored/sleeved to 92mm. This is the limit! Do the math. 98 bore spacing, give you 6mm max between cylinders for the heads to seal, not much for a SC engine.
Which I agree with. Coming to think of it, 94mm is too scary, with or without good gaskets

I 3-D modeled the stroked engine I wanted to build and ran into a challenging and expensive problem.
Precisely what I'm intending to do - I've contacted a 3D scanning outfit here in Manchester and gotten prices on the job of providing a fully editable, CNC-accurate CAD model. Not cheap, mind you, so a cost to be added to the final build.

I envy the American mods available for legends by the likes of Ford and GM, whereas the next-to-nothing available for our babes. That said, if I get my way, then I'm releasing all this work to the masses, versus keeping it close to my chest.

Out of interest, how did you go on about your 3D modelling? did you go to nuts and bolts measurements or 3D scanning?

I wanted my engine to be balanced for 7000 rpm operation. What I found is that with 92mm pistons, standard pins/rings, combined with custom steel rods, I could not get the cross-plane fully counterbalance masses on the crank to balance unless I went with heavy metal inserts or went with custom Ti rods. Due to our 98mm bore spacing, the counter balances are narrow and are limited in OD by the walls of the block.

To some degree, increasing the stroke helps with rod weight/balancing, but you will have to run the calculations for a complete custom engine build. Don't just try to throw in a custom stroked crank, without having the rods, pistons, and masses of the flywheel and front lower crank pulley included.
You open a very wide door for prudent argument. No way am I doing this by bolting together six of one and half a dozen of another stocks. I'm under no illusion that this is now firmly looking like a full custom engine build ( i.e. expensive and time consuming)

On the plus side, this will give me all the data necessary, and missing, to apply whatever else mods and designs for now and the future for these engines.


At 550+ hp you can probably get away with the standard crank design, (no center counter balances, but then you better pay close attention to engine harmonics. (The count has written abut the 4.2's harmonics.)
I was designing my engine for 700+ hp, so I had to pay more attention to rod strength (added mass) and engine balance.
My limit for the stroke was 90.2 before my rods or block would have to be modified
All hail the Count .. I've read his articles and they make for some amazing work Yes, absolutely right about the harmonics, so modeling all the way.

I'm commissioning a new 416 steel crank, so have a lot of room for mods and stress testing.


I believe that the Arden kit claims a 92mm stroke. If you are only wanting 550hp, might be more cost effective in the long run to use their kit. (if they still offer it.)
I'll check Arden, though I'm not impressed by how little they available for the AJ27

On the other hand, good luck getting much out of the M112. If you are spending the money to build up the engine go with the KB twin screw.

Absolutely. I'm considering the KB 2.8L and 3.2L. I'm also looking at the Edelbrock E-Force which is made for the Coyote. So far, the dimensions add up with the stock bonet.

One other area I'm looking at is ECM and TCM - the stock ECUs are both rubbish and too old to mod.

A final, and crooked twist, is to integrate a fully supercharged Coyote engine


Thanks again for your feedback and any contributions from anyone.
 

Last edited by ahmedalalousi; 03-10-2018 at 05:46 AM.
  #7  
Old 03-10-2018, 06:04 PM
Member
Thread Starter
Join Date: Dec 2014
Location: London
Posts: 55
Thanked 4 Times in 4 Posts
Default

Just checked Arden. Can't find any performance upgrades for the X308.
 
  #8  
Old 03-11-2018, 01:36 AM
XJR-99's Avatar
Senior Member
Join Date: Nov 2011
Location: Europe
Posts: 741
Thanked 220 Times in 167 Posts
Default

Originally Posted by ahmedalalousi View Post
Just checked Arden. Can't find any performance upgrades for the X308.
Check X350.
 
The Following User Says Thank You to XJR-99 For This Useful Post:
ahmedalalousi (03-11-2018)
  #9  
Old 03-11-2018, 05:20 AM
Member
Thread Starter
Join Date: Dec 2014
Location: London
Posts: 55
Thanked 4 Times in 4 Posts
Default

Had a look at that too. For the money, I would go my own way.
 
  #10  
Old 03-11-2018, 12:03 PM
avos's Avatar
Veteran Member
Join Date: Apr 2008
Location: Europe
Posts: 3,166
Thanked 843 Times in 608 Posts
Default

Originally Posted by ahmedalalousi View Post
Had a look at that too. For the money, I would go my own way.
I thought the 3.900 euro for the forged crankshaft, rods and bearings, was an ok price. For what do you think you could do it?
 
  #11  
Old 03-12-2018, 02:30 AM
XJR-99's Avatar
Senior Member
Join Date: Nov 2011
Location: Europe
Posts: 741
Thanked 220 Times in 167 Posts
Default

4640€ VAT included when shipped to the UK - actually the parts are manufactured in the UK... It's actually pretty cheap kit when the quality is the highest possible. Of course those parts are just a very, very small part of the whole engine/car upgrade project Maybe Trump's 25% steel tariffs hit to the kit if ordered to the USA
 
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
ahmedalalousi
XJ XJ8 / XJR ( X308 )
2
02-17-2018 07:17 PM
neo4star
XJ XJ8 / XJR ( X308 )
10
12-06-2016 09:24 AM
jaguars4r
S-Type / S type R Supercharged V8 ( X200 )
6
05-06-2015 08:44 AM
Skelly
XJ6 & XJ12 Series I, II & III
11
04-10-2015 05:14 PM
91stealthes
Jaguar Engines & transmissions
6
11-04-2014 04:46 AM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 

Thread Tools
Search this Thread
Quick Reply: Engine Block and Head Data


Advertising
Featured Sponsors
Vendor Directory

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: