View Full Version : block lightening-tr2,3,4- how much-where

03-28-2006, 11:03 AM
anyone know how much and where you can grind the triumph tr4 engine block to remove some excess weight? these engine blocks are heavy!

Simon TR4a
03-28-2006, 03:15 PM
They are very heavy!
The "normal" way to do this is with a grinding stone in a drill, by hand, unless you are Roush or somebody and have a CNC milling machine programmed to do it for you.
I would doubt the benefit of doing this for a road car, I think you would struggle to get rid of more than a few pounds.
Alternatively, get a lightweight starter, the gear reduction type, or possibly an aluminium front plate to replace the steel one. Aluminium pieces weigh 1/3 of dimensionally similar steel items. I have replaced some of the bumper brackets on my car with aluminium; but not all in case I get hit.
If you want to use "sweat equity" to replace financial investment I would start with seams left by the casting process.
Hope this gets you started!

03-28-2006, 03:33 PM
i already have the usual suspects for weight reduction mapped out as you pointed out. but i was wondering if 20 to 30 lbs can come off this block or more. get on the milling machine and start cutting. there is a lot of metal below the crank for one. since it is a 3 bearing motor it needs a strong foundation but there has got to be some serious mass that can go.

03-28-2006, 05:09 PM
Hi Rob,

One area that can be reduced a bit is the top of the webs between the cylinder sleeves. This has the added benefit of opening up the water jacket for better flow.

Aside from that, I'd mostly just clean up the casting and remove minimal amounts from the block itself. I doubt we are talking 20-30 lbs. overall, though. Afterward, sealing with Glyptal might be advisable.

I know you are talking about the block, but an aluminum cyl. head would likely be the biggest single improvement, although very pricey. Probably 20 lbs. could be saved there, and it's high up so it effects the car's center of gravity more than most pieces. Also, alu water pump housings are available, not sure how much weight savings that would amount to, but should also give slight improvement in cooling.


03-28-2006, 07:11 PM
thanks guys,
i got a response from Kas on his site and although he did not do much beyond polishing internally, he just says do it!
the serious v-8 guys do this. i look at this as affordable prep. yes i am aware of all those goodies in aluminum. it's just $$$$$. block lightening is one of those things not seen that make others go "how does he go so fast!" lighten the front of that tr4 and you can potentially go faster

03-28-2006, 07:29 PM
Hollow it all out leaving the ouside normal looking but the walls nearly thin as paper, and stuff a slightly smaller high output aluminum engine inside the cast iron shell - hehehehe. The ultimate in stealth!

03-28-2006, 08:12 PM
How much help does the rust need???? /ubbthreads/images/graemlins/confused.gif /ubbthreads/images/graemlins/jester.gif

03-28-2006, 10:55 PM
I dunno? Salt-cure the inside of the block after you hollow it out /ubbthreads/images/graemlins/devilgrin.gif It'll lighten as you drive, but be aware of post race inspections?

03-29-2006, 02:56 AM
Rob, I was always under the impression that polishing the inside of a block served two purposes.
1. To relieve any sharp edges that may create stress risers, and,
2. To aid in the surface shedding oil back to the pan.
I doubt whether you are going to see any significant weight reduction without compromising the structural integrity of the casting.
I used to coat the inside with Glyptal, but quit after I had some of it flake off and get into the oil pickup screen. Now it's merely a polished finish.

03-29-2006, 03:28 AM
Hi again Rob,

I saw Kas' response and it sounds like the tech inspection was all that kept him from shaving pounds off TRactor motors, and would have no concern about doing so. Having once carried a TR block by hand about 50 feet (when I was much younger), I agree any weight loss diet you can put it on can only be good for the car's performance. So, get out that grinder and get started!

03-29-2006, 05:32 AM
Alan, I was only referring to polishing the inside. I'm certain there are many areas of the block that can be safely carved away.

03-29-2006, 11:03 AM
i read that the v-8 guys take as much as 20lbs out of a modern v8 block so i'm sure there is that much in the tr4.
most of this is milled off the v-8's. i am in no hurry though. jeff, correct! /ubbthreads/images/graemlins/iagree.gif

03-29-2006, 05:41 PM
Seems like in many cases it would be much easier for the driver to lose weight if it were that important. even twenty pounds is a stretch.(in the engine or the driver)
Don't like racing a heavy TR?.....find a nice light modern car, some of them really go fast.

Matthew E. Herd
03-29-2006, 08:04 PM
Indeed, they're generally faster, but not too many are lighter than my midget ... /ubbthreads/images/graemlins/smile.gif

03-29-2006, 09:29 PM
I could stand well to loose about 30-40 lbs of weight! But... I'm a typical beer drinker car guy. It's all in the front. /ubbthreads/images/graemlins/rolleyes.gif

03-29-2006, 09:35 PM
better for front end crash protection? /ubbthreads/images/graemlins/rolleyes.gif

i wouldn't mind going back to 32s myself.... but I'd have to go out and purposely exercise to do that..... I might end up doing that anyways just cause i've been feeling a bit lethargic lately, once i figure out how to get the motivation to keep doing it that is.

03-29-2006, 09:38 PM
Yeah, Motivation is VERY important on any project - hehehehehe.

03-29-2006, 09:42 PM
what the heck... just dawned on me... how'd we go from "TR 2/3/4 Block Lightening" to pants sizes?

03-29-2006, 10:24 PM
heheheh classic thread stealing! one topic is a little ????, and someone decides to open a new topic - loosely relted (by their own mind), and viola! thread hijacked! I'm a master at it, and so are about 5-6 other guys on here. LOL usually no-one notices... Go back to sleep Rob.... go back to sleep!

03-30-2006, 11:43 AM
ok guys (and gals),
the lump is out there in front. when we sit our lumps in the seat it's near the middle. the back end is light so reducing front end weight is a good thing on a 4. it helps with the balance of the car. this IS the racing forum! ya something new would go faster but that's not the point. the point is to make our old british cars faster.

Matthew E. Herd
03-30-2006, 02:25 PM
Amen! /ubbthreads/images/graemlins/thumbsup.gif

03-30-2006, 09:09 PM
you moved the battery back already right?

03-31-2006, 11:11 AM
aluminum rad too.