Engine and Transmission Tech

Hi All,
I seek the general wisdom :? of this new forum on replacing my block hugger headers on my Rover 3.5/3.9 EFI.
At the begining of the season, I detected some cracks in my headers welds at the collectors (common problem) , so I had them welded.
I digress:
There were new mild steel block huggers from about 1992, they had the single metal flange, but they still cracked. Before I installed them in about 2002-3, I had them flow coated and ceramic coated. I ran them for 4 years unwrapped, but I had excessive heat in the engine bay.
So before diving cross country in the summer, I removed them to heat wrap them.
This is when I found the cracks in the welds.

So off to a friend to get them welded, only to find that they were so thin it was difficult to weld without blow through. He did his best using flame and rod to build up as much metal as possible. So I wrapped them and they lasted almost 8000 more miles of driving around the USA this summer.

I suppose they lasted as long as I expected, through the summer and kept the exhaust inside the tubes and out the tail pipe. Now they are toast after 5 years and about 50k miles of service. Should I be satisfied they lasted 5 years and 50k miles? (actually 4 years before having to be welded up)

In order to reduce engine bay heat, I will be definitely wrapping them again, even though the first 4 years of service, my old units were not wrapped. The difference in reduced engine bay temps between an unwrapped header and wrapped header is indeed 70%-80%! and makes a huge difference in how all the stuff under hood functions - personal experience - like starter, fuel system, alternator, sensors, and Air Conditioning, etc. So I will be going to stainless steel.

I must have block huggers on this Rover because this is in a Stag and no room on the steering side. Due to the differences between the exhaust port angles of the Rover (vertical) and Stag engine (angled inward), there is simply no room for anything else except a full custom made set, or block huggers. Even OE cast iron manifolds hit the steering column.

So I need to replace the headers. Question is, who has the best block headers for the best price to fit a Rover 3.5 in North America? Maybe someone running a end of season sale? I will only buy stainless this time, but I want a manufacturer who uses thick wall tube and 1st rate welds.

Let the discussion begin!

Thanks!

This isn't a direct answer (because I don't have one)... but perhaps this article will be a useful reference.
[www.britishv8.org]
(I hope it enhances the discussion, rather than curtailing it.)

I'm very curious to hear about current sources. One of my goals is to catalog pictures and specs of competitively sourced products (like headers) so that selecting parts won't be such a crapshoot anymore.

---

Glenn, I know you'll probably be reluctant to cut sheet metal... but the experience of many, many MGB engine swappers is that venting the inner fenders is by far the most effective way to reduce engine compartment temperature AND simultaneously increase airflow through the cooling system (whether you route headers through the fenderwell vents or not!) The wheel wells are at relatively low pressure when the car is in motion. Here are two examples:

From the Aston-Martin factory:


Bruce Mills' high-class louvers:

Thanks Curtis,

I know I can get block huggers from like D&D Fabrications (aluminumv8.com), but I know that these are sourced from one of the regular header manufacturers. For D&D price, I can get some custom units made to my specifications at Nolan Enterprises in Wheat Ridge.

I have sent a bunch of photos to Summit Racing to see if they can locate block huggers from one of the large header manufacturers. I know they are out there in the $150 range for mild steel and $250 for stainless.

Yeah, most racing applications do open up the whole engine compartment, wheel wells and all. I probably need to visit that possibility to see where the best places are to add venting, what type, eliminate road wash issues, etc.
Vents are easier to install before the engine goes in of course ! Also, it is idle engine bay temps in traffic that really are the issue for me, so the solution there was wrapping the headers - worked very well. At road speed, everything is fine, what goes in - gets out. The problem with the Stag is no frontal area to get the volume in.

That Aston Martin photo is definitely something to think about.

The problem of routing headers out the wheel wells on a Stag is that this is a McPherson strut system and a unibody , there is no room in the wheel wells for exhaust pipes. Plus they would need to drop below the frame outriggers right into a rock bite area on both sides. It is bad enough I had to relocate fuel lines there.

Might be time for me to finish the OE Triumph OHC V8 and get it back in. The other install was effective and fun, but not real pretty. What do you think I could get for my Rover 3.5 w/ 3.9 EFI, harness and computer, including the 5 speed? $2500?

Glenn,

My TR6 is pretty tight to the sides and I initially thought I would have to run block huggers.

But I discovered that the factory Buick 300 manifold works beautifully on the driver's side. It stays close to the block and is a staight bolt-up to a Buick/Olds head as you know. A stock 300 passenger's-side exhaust manifold would not fit my car because it dumps out after the rear-most cylinder and would have had to enter the passenger side footwell.

I solved that with a pair of 300 manifolds, a hacksaw, and a skillful welder friend able to weld cast iron. (He's an engine builder and ace fabricator.) My pass. manifold uses the front half of the stock piece, plus the front half of a driver's side manifold flipped and pointed toward the front of the car. The downpipe flange portion is from the passenger side manifold filed to sit flush against a rounded pipe. To do this, I used a spare head on a workbench. I bolted a 300 driver's side manifold to it and marked the centerline--the point midway between the two inner exhaust ports. I sawed down that line. I then mounted a driver's side manifold backwards to the head, marked the same centerline and sawed down that line. (Putting the two front halves together gave me a two-piece manifold with no outlet.)

Next I sawed off the exhaust flange from the back of the passenger side manifold; I made that cut high--not in the tube incorporating the exhaust-system flange but rather in the other pipe--the one fed by each exhaust port. This left the cut end with the same contour as the collector pipe such that I could set it against my bolted-up halves and it would sit flush.

Now it was time to pick the spot where this pipe should dump down. This time I bolted the two halves in place on the passenger-side cylinder head of my installed engine. I got on my back, sighted the line I would need it to take to send the downpipe behind my motor mount and ahead of my starter and set the third piece in place. I marked around the base of the third piece on the bolted-up halves with a sharpie, unbolted the halves and filed out the portion on the two halves inside of the sharpie outline (leaving a margin welding).

After this, I had the three pieces that would make up my new passenger-side manifold. I took them and a spare head to Adelmann Engine (any shop with a welder who knows how to weld cast iron will do). We bolted the two halves to the spare head, he welded them together; then he set the third piece in place and saddle-welded that to the outside of the two halves. We left it all bolted together to cool overnight so it wouldn't crack.

Now I have 300 manifolds on both sides and they look and work great. To do this you need a spare 215 head, two driver's-side 300 manifolds, a passenger side manifold, hacksaw, sharpie, good welder, and about an afternoon of cutting and measuring. It sounds complicated, but I did the cutting, filing and measuring in a couple hours.

I'll be out tinkering this afternoon and will see if I can get a camera in there to get a worthwhile photo. I'll post it if so.

I have another possibility for you. Before the blockhugger idea and the 300 discovery, I turned another fabricator loose and he made me some headers in the manner of the Limefire Roadster, a famous hot rod. I paid about $800 for them, but they protrude slightly beyond the back of the block and would have required modifying my firewall. They're high quality pieces made right. If they would fit your application, I'd let you have them for a set of blockhuggers, as they won't fit my car in its current form and I have no plans to cut the firewall when my 300 manifolds work so well. I'll post some pictures of them later too.

You sound very knowledgeable. Shops that do a lot of Stag motors have learned some tricks to get past their stock shortcomings. Rather than just rebuild, you should research this if you haven't so that your rebuilt mill is good for 100,000-plus miles.

Kris

motormouth Wrote:
-------------------------------------------------------
> Glenn,
>
> My TR6 is pretty tight to the sides and I
> initially thought I would have to run block
> huggers.
>
> But I discovered that the factory Buick 300
> manifold works beautifully on the driver's side.

I will need to locate a set. and see if that will work. The stock Rover center port exit ones are very very narrow, and still hit my steering linkage.

>>
> I solved that with a pair of 300 manifolds, a
> hacksaw, and a skillful welder
>
>

I have a good nickel welder available here in Boulder

>
> After this, I had the three pieces that would make
> up my new passenger-side manifold.
>
> Now I have 300 manifolds on both sides and they
> look and work great. To do this you need a spare
> 215 head, two driver's-side 300 manifolds,
>
> I'll be out tinkering this afternoon and will see
> if I can get a camera in there to get a worthwhile
> photo. I'll post it if so.

That would be great! Photos ...
>
> I have another possibility for you. Before the
> blockhugger idea and the 300 discovery, I turned
> another fabricator loose and he made me some
> headers in the manner of the Limefire Roadster, a
> famous hot rod. I paid about $800 for them, ... I'd let you
> have them for a set of blockhuggers, as they won't
> fit my car in its current form and I have no plans
> to cut the firewall when my 300 manifolds work so
> well. I'll post some pictures of them later too.

Cool, I'd like to see them.
>
> You sound very knowledgeable. Shops that do a lot
> of Stag motors have learned some tricks to get
> past their stock shortcomings. Rather than just
> rebuild, you should research this if you haven't
> so that your rebuilt mill is good for 100,000-plus
> miles.

Well Chris, I am the Chairman of the Triumph Stag Club USA and was president from 2001-2007. We have given the shops the tips and tricks so we know the Original Triumph V8 OHC can do over 100000 miles reliably, provided quality parts are also sourced and correctly installed.

My goal is to build a streetable 300bhp Triumph OHC V8 using some modern engine tricks applied to the original Triumph V8 design.

I'll look for those photos.

Glenn

OK Glenn, let's see if I can figure out how to post these.

Here's the passenger side 300 manifold with front portion genuine pass side and rear portion the front of a driver's side.

Different angle. They protrude about 2-3/4 inches from the head.

Yet another angle better showing fender clearance.

This shot is tight--it was the best of about 8 I took from under the car. At the bottom of the photo is the starter. That little bit of yellow is the tape measure in the same place as the above photos. You can see a bit of the weld here and the connection to the flex pipe I'm using to send exhaust back until I get my car over to the exhaust shop for some downpipes. Custom manifold sends pipe ahead of starter and behind motor mount.

Glenn, if you think this might be your answer, let me know and I'll pull the passenger side manifold off the car and shoot it ten ways to Sunday so you can really see how it fits together.

Here are the other manifolds I mentioned. Not as attractive as the 300 option, but they fit real tight to the heads. Clearance is about 2-1/4 inches. They protrude backward about an inch further than the back of the head. Instead of going in front of the starter, this design goes behind it.
[Guess I've hit the maximum number of attachments. I'll post photos of the other manifolds below. KP]

Sounds like you're in good shape on the stock motor. I've always liked the Stag and they're reasonably priced for the amount of car you get. I've read a lot about them in Classic & Sports Car and it's on the short list of cars I've been trying to get my brother to buy--ten years in California talking about a convertible and he still hasn't bought one!

Kris



Edited 3 time(s). Last edit at 11/05/2007 03:06PM by motormouth.

Glenn, here are the other manifolds I mentioned. I trust the fabricator to have made them well but nobody's gonna be swooning over them. About as tight as you can get to the heads, though.

WOW. I thought I had it tough with the Vega. NOT EVEN CLOSE. You guys have to be pretty creative. That's a really good idea about the vents to the fender... I might do that too.

Thanks Kris for the great photos. Things in the Stag are quite tight, and I run AC too so that rules out your custom set of $800 tubes that extend forward, reversing them of course would hit the starter..

I may consider some slice and dice of some 300 manifolds like you did, but I will need to make sure my local professional cast iron welder agrees they will not crack on the welds after a few dozen heat/cool cycles. They have a complete forge setup and can heat the cast to very high temperatures before welding and cool it over a few days

Making that weld absolutely perfect when joining two separate cast pieces is of course critical, followed by a very long cooling period or tiny cracks will develop
.
I think most cast welding people agree that repairs like cracks in cast iron can be made, but if the pieces are for structure pieces, they should be staked or bolted together to make the mechanical structure, then sealed with the weld.

That is a lot of trouble. I think I will go with another set of block huggers.

Glenn, did you see that there's a set of original (iron) MGB GT V8 manifolds for sale CHEAP in the classified section? Not the best flowing option, but they might suit your Stag... they'd be quieter than tube headers. If you really do go back to the Triumph engine someday (eeek!) you could recoup your investment by selling them to an MG restorer.

Moderator Wrote:
-------------------------------------------------------
> Glenn, did you see that there's a set of original
> (iron) MGB GT V8 manifolds for sale CHEAP in the
> classified section? Not the best flowing option,
> but they might suit your Stag... they'd be quieter
> than tube headers. If you really do go back to the
> Triumph engine someday (eeek!) you could recoup
> your investment by selling them to an MG restorer.



Curtis, Thanks for the heads up! I will send Dave a PM, and add a note on the classifieds add too.

Okay,
I finally realized that I may as well grab a set of block huggers from Mark at D&D (www.aluminumV8.com). He had them in Stock and I will be able to extend my drive season before the highway department starts spraying Mag Chloride. $275 plus shipping for mild steel painted.
Should have them on Friday.

For a Stag, these need a bit of 2" rearward modification to the down pipe exiting the collector to miss the cross member on the right, and 2" rearward to miss the power steering rack pipes on the left. This makes a "handed" set of exhausts

Photos before and after once I get them modified.

Woody Cooper also sources Block Huggers, but he did not have them in stock.

One day I will find out where these guys get their headers made here in the USA.

Cheers!

Glenn

I'm looking for headers also for a Skylark. I don't like the Blockhuggers. Is Nolans Enterprises, Nolans RV? If so who is your contact there? Do you know if they do quality work?

TIA, Doug

Doug,
Please excuse my lousy memory, It is not Noland Enterprises.
It is:
Mark Lupfer Enterprises
5580 Harlan Street
Arvada, Colorado 80002
(303) 425-4578

Quality was first rate. He had no tube bender though, he buys prebent tube, cuts as required for the longest runs.

I'm interested in this discussion since I'm considering fitting a Rover/215 into my TVR 2500.
Exhaust headers will be an issue because of the position of the tubular frame rail. Any help from anybody who has completed such a project would be most welcomed. So far, I think a promising option is the stock Olds 215 cast iron headers. I have never really heard much about people using them for conversion projects. Here's some pics of a collection of headers:
RV8 syle (MG), Rover P6, Rover SD1, Olds 215.

Pics

There are another style of Blockers that are 4 into 1 "Y" style collector and tighter to the block.

These I bought from Mark at D&D, black painted mild steel. Price is right, cheaper than having a set made custom. Note that they include new bolts and gaskets.

Here is a question: On these welds, they are absolutely flawlessly smooth, and welded that way. I have never seen welds like that before, most all the welds having uniform ripples. Penetration on the both sides of the steel looks perfect. I can not imagine that these things were machine welded, it has got to be someone who really has a perfect hand to weld motion.



Edited 1 time(s). Last edit at 11/23/2007 06:50PM by StagByTriumph.

I know where you can get some 300 cast iron manifolds. I recently sent some to jim blackwood for the Roadmaster project, as swap material.