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Sydney.Wedgehead Sydney Wedgehead
Sydney, NSW, Australia   AUS
Hi Vance,

That's a big re-bore. I hope it serves you with a reasonable life. Is it a Rover or Buick block? I've only seen Rover here and heard they had real problems with core shifts in casting.

I think Rover really pushed the limits when going introducing the P38 with the 94 mm bore. The first P38 motor I purchased (to replace the SD1 with fretted main bearings) failed a pressure test and showed cracks behind No 6 cylinder liner. The replacement is better, but I worry about this vulnerability.

My takeaway is don't overheat or over-torque the heads on RV8s.

Owen

In reply to # 1470231 by Darth V8R
In reply to # 1470157 by Sydney.Wedgehead Thanks Vance.

I'll keep your suggestions in mind when choosing the cam.

Is your RV8 a 3.5?

Do you recall what lifters you went with?

Owen

Owen:

I went with CompCams lifters. Plain old lifters, didn't bother with anti-pump up lifters, as it was never going to go over factory red line. Hey, it's a street motor.

Yes, it is a 3.5 with 0.060" (1.5mm) overbore and 10:1 pistons. So it comes out to about 3.7 liters. I had to go with custom cast pistons because 1mm overbore is as big as anyone goes off the shelf - and they weren't much more than the off the shelf items. Using NOS Buick rings, and ARP studs for the rods and main bearing caps. Stock rods and crank, OEM windage tray. I installed the cam 4 degrees advanced, per Crower's recommendations. K&N air filters with OEM cold air intake, plain butterflies in my ZS carbs (OEM had poppet valves, which reduce the air flow) and new carb needles. Mild port job on the head with ARP head fasteners, OEM steel head gaskets.

OK, so it is an extreme overbore and not recommended. May well go BANG one day. (Honey! My engine broke... Can I please buy a Rover 4.4 engine? Please?)

Bwuh-hah-hah-haaah!


Vance


P.S. with all of this, I am still a girly-man compared to TR8Todd. He is a total maniac, currently building an ICBM disguised as a wedge.

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TR8todd Avatar
TR8todd Todd Kishbach
Mass, USA   USA
1977 Triumph TR7 "Rally Fraud"
1978 Triumph TR8
1979 Triumph TR7
1980 Triumph TR8    & more
A buddy of mine has a 3.5 that was built back around 1990. It was a very expensive build even by today's standards. He was told by the previous owner that had the engine built that the blue print for the engine came from a book written in the 60s about the Buick 215 race engines. His engine has a Buick 300 heads, crank, rods, and pistons which have a 3.750 bore. The PO never put many miles on the car after the build. My buddy did. At least up until he started having engine troubles. Upon teardown, its evident that at least 2 of the sleeves have shifted. Engine has sat for 4 years now. Can't seem to find a way to put it back together again as a "big" engine without spending at least $5K. It will probably go back together with a junkyard 4.0 or a rebuilt 3.5 because thats all the budget allows. Explored resleeving a block($2K), rebuilding a 4.6($3.5K plus core plus acquiring new flywheel and clutch). Even looked at just rebuilding a 300. Problem is everything he has is matched to a Rover 3.5 block 300 heads, 300 crank, custom flywheel, and a Rover trans. Every less expensive option to resleeving a block involves changing out components like flywheels. Those other expenses all seem to keep adding up to a price over budget. In his defense, he has another TR8 with a big engine thats really fast, and a nice daily driver quality TR7 coupe.

jacko241 Avatar
jacko241 Silver Member Joe J
Saint Augustine, Florida, USA   USA
Sorry to highjack slightly, but will the Edelbrock 2198 carb manifold fit a 4.0 liter out of a 2001 LR D2?

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TR8todd Avatar
TR8todd Todd Kishbach
Mass, USA   USA
1977 Triumph TR7 "Rally Fraud"
1978 Triumph TR8
1979 Triumph TR7
1980 Triumph TR8    & more
Yes. It will fit any Rover V8 with stock heads except the ultra rare 4.4? Liter engine that came in some trucks down under. You won't come across one here in the states unless you put serious effort into finding one. It won't fit if you use aftermarket heads, nor will it fit well if you use Buick 300 heads unless you run adapters. Those heads are taller and as the V of the engine raises higher, the intake won't sit inside the V any more without spacers. Same goes if you run a taller deck 300 Buick block, but thats a different story. 4.0 block and heads? Your good to go. Bolt it on and spend your time worrying about how to make the ignition work without a distributor provision on the front cover. Cheapest place to buy a new Edelbrock intake is Summit, $280 plus they have free shipping. I have several used ones I'd part with if you want something even cheaper. If you go with the Edelbrock, you will need to source a T-stat cover and a rear water neck. TR8 ones can get pricey. Buick ones are cheap. Avoid those chrome ones. They all seem to leak. One last thing. If you go with the Edelbrock, make sure you drill a hole inside the Tstat area of the manifold so water can bypass the t stat when its closed. Or you can just drill a 1/4" hole in the T-stat. If you don't, the water won't circulate past the T-stat and you will get a big pocket of really hot coolant before the T-stat finally opens. All the stock intakes have this provision, but Edelbrock hasn't realized they have an issue yet.

jacko241 Avatar
jacko241 Silver Member Joe J
Saint Augustine, Florida, USA   USA
Thanks Todd. You are a fountain of useful info. If you have any suggestions on ignition, I would love to hear them, but my plan was to use an Electromotive crank fire setup.

Darth V8R Avatar
Darth V8R Vance Navarrette
Beaverton, Oregon, USA   USA
1980 Triumph TR8 "Wedgie"
In reply to # 1470161 by tr7v8mike Hi Owen, my engine is also a P38, but stroked out to 4.6 with 10:1 CR. the cam is a Crane 206 and I'm happy with it. Smooth idle, easy start and I can creep along in traffic without too much hassle and I'm happy with performance on hillclimb events.
Do you have your manifold and carb yet?
Mike

Mike:

Thanks for mentioning Crane, who also make excellent cams. That is a good choice for a street driven car, almost identical to my Crower but with a bit more duration on the exhaust.

I went looking for a Crane cam when I built my engine, but I believe they are now making cams for the Rover/Buick engine by special order only. I didn't want the hassle, so I went with Crower.

Glad to hear you are happy with the cam. So many people over cam their motor, and end up with a burping fuel hungry monster. I have done this myself, on my very first cam swap. I blame the hot rod magazines who build up a 350 ci V8, throw a cam in with 230i/238e or more duration, and show the dyno chart making 350HP, or 60HP/liter. Then someone says "I can do that too" and finds out how miserable they are with that camshaft on the street. When you go back to the magazine, you notice that they do not show the power below 2,000 RPM, which is practically non-existent - oops, and make no mention of the idle or fuel economy (bad, and really bad respectively). And forget passing emissions if you are in an area where you get tested.

If you are auto crossing or racing, then none of this matters of course.

Great stuff.

Vance



1980 Platinum Metallic TR8, navy blue interior
Bare metal respray, Crower cam, raised compression
ported heads, modified Zenith carbs, 0.060" overbore

Darth V8R Avatar
Darth V8R Vance Navarrette
Beaverton, Oregon, USA   USA
1980 Triumph TR8 "Wedgie"
In reply to # 1470420 by Sydney.Wedgehead Hi Vance,

That's a big re-bore. I hope it serves you with a reasonable life. Is it a Rover or Buick block? I've only seen Rover here and heard they had real problems with core shifts in casting.

I think Rover really pushed the limits when going introducing the P38 with the 94 mm bore. The first P38 motor I purchased (to replace the SD1 with fretted main bearings) failed a pressure test and showed cracks behind No 6 cylinder liner. The replacement is better, but I worry about this vulnerability.

My takeaway is don't overheat or over-torque the heads on RV8s.

Owen

Owen:

It is a real Rover 3.5 block.

The issue with core shift was on the larger engines - 3.9 and above. The reason was that the cylinder liners had to be enlarged to accommodate the increase in displacement - this meant that the bores in the block itself had to be enlarged, which thinned the casting walls that supported the liner. So far, so good.

But when the cylinder heads are mounted, and the head bolts tightened, the load imposed by the bolts on the threads in the block caused the block to crack in the vicinity of the bolt, and that crack would always occur next to the cylinder where there was less aluminum to support the load. The block would lose its grip on the liner, and the liner would slip down into the block. Much engine mayhem and colorful metaphors by the owner ensued. sad smiley

This always happened where the block casting was thinnest, which of course depended on how much the core moved around during casting.

This problem never (as far as I have read) happened on 3.5 blocks as long as 3.5 cylinder liners were used, since the liners are smaller on the 3.5 motors. My motor still has the original 3.5 liners, so block cracking is not (?) an issue.

After reading all of this, I decided to do what I could to avoid the block cracking issue anyway, even if 3.5 engines were alleged to be 'safe'. I did some measuring, and determined that all the cylinder head bolt holes would accept bolts 1/4" longer than the factory bolts. So I ordered ARP bolts that were all 1/4" longer than the originals. This spreads the load over a larger thread area in the head, and so is less likely to cause cracking. Or that is what I am hoping.. confused smiley

What is an issue with my motor is the thinness of the liner after being bored out that much. That is where the risk occurs. If the liner gets thin enough, I risk having the liner bulge under the pressures generated during combustion, the rings partially lose their seal, and I start getting blow-by and loss of power.

Thanks for the best wishes regarding engine life.

Keeping my fingers crossed,

Vance



1980 Platinum Metallic TR8, navy blue interior
Bare metal respray, Crower cam, raised compression
ported heads, modified Zenith carbs, 0.060" overbore

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TR8todd Avatar
TR8todd Todd Kishbach
Mass, USA   USA
1977 Triumph TR7 "Rally Fraud"
1978 Triumph TR8
1979 Triumph TR7
1980 Triumph TR8    & more
You have options. Go back to a SD1 type cover or Buick cover and run a Dizzy. Use a 4.0 intermediate cover where the dizzy boss is still there but not machined out. Machine it out and run a dizzy. Use the cover that came with the 4.0 and run a crank trigger ignition. Stock 4.0 was triggered by a sensor aimed at the teeth on the flywheel. Don't know of anybody that reused that trigger. Most make a 58 toothed wheel mounted on the crank pulley and then ran a megajolt or similar. Will Parris would have a better idea on how to run this. He has megasquirt on his TR8s, both the Rover powered one and the LS powered one. Whatever you do, stay away from that crap Mallory puts out there for the Rover.

Helzy Avatar
Helzy Silver Member Kent Blair
Calgary, Alberta, Canada   CAN
1978 Triumph TR7 "Lady Di"
In reply to # 1470569 by TR8todd Whatever you do, stay away from that crap Mallory puts out there for the Rover.

This is interesting. When I bought my TR7 it had a Mallory hyfire 6. Fifty miles into my journey home on the afternoon of purchase the ecm packed it in leaving me stranded on an off ramp on the busiest highway in Alberta. As I had all the extra parts and bits in the boot, the ignition kit had come with a loop back plug. Unplugged the hyfire from power and the ignition harness and plugged the loop back in and I was on my way again. Dizzy and coil are from the Mallory kit but working well without the ecm anyway.

To note the cam conversation in this thread, my 3.5 is bored .020 over with 10.5 compression pistons, and a fairly aggressive Erson cam that doesn't appear in their catalog I thought it was a performer but nope little more aggressive than that - Lift 504 Adv. Dur 296 Dur@.050 220 and LC 109. Wife calls it an 'Applecart' it idles about 950rpm when warm and you definitely do feel the applecart effect, but you also feel a nice kick in your butt even with the 2.84 rear end.



Edited 1 time(s). Last edit at 2017-07-14 10:20 AM by Helzy.

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Darth V8R Avatar
Darth V8R Vance Navarrette
Beaverton, Oregon, USA   USA
1980 Triumph TR8 "Wedgie"
In reply to # 1470425 by TR8todd A buddy of mine has a 3.5 that was built back around 1990. It was a very expensive build even by today's standards. He was told by the previous owner that had the engine built that the blue print for the engine came from a book written in the 60s about the Buick 215 race engines. His engine has a Buick 300 heads, crank, rods, and pistons which have a 3.750 bore. The PO never put many miles on the car after the build. My buddy did. At least up until he started having engine troubles. Upon teardown, its evident that at least 2 of the sleeves have shifted. Engine has sat for 4 years now. Can't seem to find a way to put it back together again as a "big" engine without spending at least $5K. It will probably go back together with a junkyard 4.0 or a rebuilt 3.5 because thats all the budget allows. Explored resleeving a block($2K), rebuilding a 4.6($3.5K plus core plus acquiring new flywheel and clutch). Even looked at just rebuilding a 300. Problem is everything he has is matched to a Rover 3.5 block 300 heads, 300 crank, custom flywheel, and a Rover trans. Every less expensive option to resleeving a block involves changing out components like flywheels. Those other expenses all seem to keep adding up to a price over budget. In his defense, he has another TR8 with a big engine thats really fast, and a nice daily driver quality TR7 coupe.

Todd:

Your friend ran into the same problem Rover did when they increased the bore without modifying the block casting. A 3.75 bore would be a 6.3mm overbore, which would more than completely remove the stock sleeves from the block. So your friend had to remove the original sleeves, bore the block, and press in new, larger sleeves. As I mentioned, that reduces the amount of 'meat' securing the head bolts, so the block cracks in the bore next to the head bolt and the sleeves drop.

The fix these days seems to be using "top hat" sleeves, and cutting a ring around each cylinder in the block deck. That way the sleeve is secured by the press fit of the sleeve in the block, AND by the rim on the sleeve, AND by the clamping force of the head. If the block cracks the sleeve is not going to move.

$2k to re-sleeve seems exorbitant. I could believe $100 a hole, but $250 a hole? Crikey!

Vance



1980 Platinum Metallic TR8, navy blue interior
Bare metal respray, Crower cam, raised compression
ported heads, modified Zenith carbs, 0.060" overbore

TR8todd Avatar
TR8todd Todd Kishbach
Mass, USA   USA
1977 Triumph TR7 "Rally Fraud"
1978 Triumph TR8
1979 Triumph TR7
1980 Triumph TR8    & more
Yea, I meant resleeve with top hat liners. Best price I know for top hats is around $1700 but then you have to ship the block both ways. That price includes liners, machine work to install and then deck the block once they are installed. Does not include boring the block to fit whatever pistons you choose. Thats the basic starting point for a stroker build. Now offset grind the crank and add slugs of heavy metal to rebalance the crank shaft. Buy forged pistons, and balance the entire rotating assembly. You can see how a "big" Rover engine can add up to well beyond what a LS3 crate motor costs.

Darth V8R Avatar
Darth V8R Vance Navarrette
Beaverton, Oregon, USA   USA
1980 Triumph TR8 "Wedgie"
In reply to # 1470699 by Helzy To note the cam conversation in this thread, my 3.5 is bored .020 over with 10.5 compression pistons, and a fairly aggressive Erson cam that doesn't appear in their catalog I thought it was a performer but nope little more aggressive than that - Lift 504 Adv. Dur 296 Dur@.050 220 and LC 109. Wife calls it an 'Applecart' it idles about 950rpm when warm and you definitely do feel the applecart effect, but you also feel a nice kick in your butt even with the 2.84 rear end.

Kent:

That is definitely an aggressive cam. Honestly, you are well into racing cam territory. Guys like you make me feel like a girly-man.

I presume that you had the valve guides cut down, as that much lift will crash the valve spring retainers into the top of the valve guides on an otherwise stock motor. Are you using stock valve springs? I would be worried about coil bind with that kind of lift.

Cheers,

Vance



1980 Platinum Metallic TR8, navy blue interior
Bare metal respray, Crower cam, raised compression
ported heads, modified Zenith carbs, 0.060" overbore

Helzy Avatar
Helzy Silver Member Kent Blair
Calgary, Alberta, Canada   CAN
1978 Triumph TR7 "Lady Di"
In reply to # 1470774 by Darth V8R
Kent:

That is definitely an aggressive cam. Honestly, you are well into racing cam territory. Guys like you make me feel like a girly-man.

I presume that you had the valve guides cut down, as that much lift will crash the valve spring retainers into the top of the valve guides on an otherwise stock motor. Are you using stock valve springs? I would be worried about coil bind with that kind of lift.

Cheers,

Vance

Naw, not girly-man at all. I had planned to put a 3.9l together on my own with a mild build looking for 200ish HP and had another TR7 FHC for a transplant. When this came available locally, I essentially abandoned that plan as the 3.5l in this 78 FHC was purpose built by Woody Cooper the other main bits to the build:

-Engine 3.5 Bored 0.20, Fully Balanced, new 10.5 compression Pistons.
-Erson Camshaft Lift 504 Adv. Dur 296 Dur@.050 220 and LC 109.
-Cloyes double timing chain.
-Internal changes for higher oil pressure.
-Heads fully ported including bowls.
-Heavy Duty valve springs.
-Larger High Flow valves- Intake  41.4 mm Exhaust 35.5.
-Brand new 600CFM 4 barrel Holley carb.

Woody Dyno'ed it at 260HP

The motor currently has about 300 miles on it. Just haven't had time to drive it much, I want to add a couple of gauges discretely for temperature and oil pressure etc. before I get into the throttle much as I noticed last weekend in the 30 degree + heat (it was between 85-95 all weekend here last sat/sun) it looks like I have an oil drip on the right side that I want to remediate this weekend too. Noticed a few other concerns I hope to get to this summer with some steering shudder at low speeds (not certain this doesn't have something to do with a 7" front vs 8" rear stagger but all of the running gear / suspension etc is all new so putting it on a friends home lift and going to have a nice once over.

Solid fun car to drive though little concerns notwithstanding, beats the crap out of the 80 TR7 DHC I had many years ago!

dhuddleson Avatar
dhuddleson David Huddleson
Manotick, Ontario, Canada   CAN
It is very rare to have had anyone report a 3.5 Rover V8 that dropped a liner, but many years ago at the TRF Summer Party someone invited me over to their car to show me their little "treasure box" in the trunk. In there he had a full cylinder liner that had become so loose it simply slid right out when they disassembled the motor. Before disassembly it supposedly made some serious knocking sounds (yeah, I bet...)

My own story is with the later 4.0 and 4.6 as fitted to Disco I & II and P38 Range Rovers. I had a 1998 D1 with 4.0 and one day driving to work it had a strange light shake or shiver when stopped at traffic lights. It still had plenty of power, but then the Check Engine light came on to indicate something more ominous. Check my photos of the end result, a liner that dropped a significant amount. I still have that block and may yet use it for something as otherwise it is in great condition.


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diver Richard Crothers
NorthEast, Maryland, USA   USA
For those that have a Mallory setup, get rid of it. Mallory is no more, they were bought out by MSD.
I was in the middle of installing a new Mallory distributor in my Buick engine when it decided not to work. They could not fix the problem so the old distributor went back in. Later I found that Mallory had bought out by MSD. Ask about Malloy my distributor not working, no problem and MSD set me all new parts no charge, works great.

Diver

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