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Time to start working on the 8

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PATR8

PATR8

Jedi Knight
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Ok, winter is here, son was home from VMI for Christmas and headed back, daughter has been accepted at several colleges so that stress is gone. I have purchased a deisel Jetta for my daily 130 mile round trip to work (44 mpg average), the holiday season is over, time to turn to my 8. I need some time with the Triumph to releive the stress

I know I need my right head reworked, it has been smoking out the exhaust a litle more the past two years. I will take both heads off to have reworked. What else should I do? It has been 10 years + since I rebuilt the engine, what else should I do. I beleive last time got got new head bolts, I beleive I should do that again. I need new gaskets for the heads and manifold and headers, What am I missing? What have I forgot? Is there anything else I should look at while I am eyeball deep in 3.5 litres?
 
First thing would to, if you have not done this get the heads cleaned up & ported to match the headers. Do the upgraded valve springs.
 
The head bolts are reusable. The only bolts I know of that you should not reuse are the rod bolts on the 4.0 and 4.6. Once the heads are off, check the bores. Do a compression test before you tear it down. Treat yourself to a new cam, lifters, and double row timing chain. Don't go crazy on the cam, you'll just end up with a poor idling stinky fuel smelling car. I had three different engines built this year. Pretty standard stuff. Hone block, polish crank, install new bearings, rings and seals for the lower end. Had one crank that needed to be turned. If you want a little more performance, spend the money on the heads. Common practice is to install the bigger Rover Vitesse or even bigger Buick valves, Chevy springs, and a mild port on the runners. Head work does not have the cost vs reward for a 3.5 as it would be on the 4.0 and larger engines. Here is a link to the engine shop that does all of the local Rover engine stuff. They have built over 100 Rover V8s including stroker builds.

https://www.precisionengine.net/
 
Major, glad to see you Back. Son still thinking Naval Academy , Norwich ,And VMI. Now MIT is in his head.
When the heads are off, and i suggest just buying 4.0 heads from Woody to replace them, is to inspect the sleeves in EACH cylinder. I thought I had a lifter noise and did the top end last year and did not check the sleeve heights. Wasted my time and now have to tear it down again to replace the bottom end
 
I had the heads cleaned and ported the first time I rebuilt the engine, not worried there. I had not thought of bigger valves and springs, what is the benefit of that commpared to 4.0 heads?

My son heads back to VMI Monday, on the 23rd they have break out (they are no longer Rats but are then considered cadets). Having friends with kids at West Point, the Air Force Academy, The Citadel, there are no comparisons to VMI. At VMI, you have to want to be there, not an easy day there for the Rats. I am so proud of him for working so hard to make it through. The kids at the school truly show what tradition and honor mean.

A visit to VMI is a must just to get an idea of what the school is about. Ok, off that soap box. Glad to be back, I feel so busy all the time
 
The 4.0 heads have a smaller combustion chamber. They will bump your compression from 8.13 to 9.35. They also have slightly bigger runners. That swap in of itself might yield 5HP and a higher torque curve. You will need a little more radical cam to see any benefit as the extra power is gained higher up in the rpm range. Hardly worth the expense unless you happen to have a set laying around. The bigger valves can net you upwards of 20 HP on a 3.5 depending on how radical you get with a cam and compression ratios. Again, all up high in the rpm range. The choke point on the Rover V8 is the cylinder heads. They simply don't flow enough air to make a ton of HP. This isn't as critical on a 3.5 compared to a stroker motor, because your not asking the engine to flow nearly as much air. Any Rover engine over 4.0 and the heads become a serious liability. The best flow numbers I have seen were on a set of Buick 300 heads with Buick V6 stage 1 racing valves. The valves measured 1.77 intake and 1.5 exhaust and almost touched each other in the bores. Serious work went into making these things work, but they went on a 4.9 liter that made awesome power numbers. TA performance has been working on new aftermarket affordable heads, but they are not available yet. You can buy Wildcat or Merlin heads out of England, but they come with their own set of install problems to overcome. Just build yourself a basic 3.5 with a modest cam, headers and a four barrel. The rest of the stuff the vendors are pushing is just for bragging rights. Unless you are going to race your car, you don't need to spend thousands of dollars chasing a few extra ponies at the expense of drivability. Been there, done that, seen way too many blow up! Consider this advice from someone who isn't trying to make a buck off of you.
 
I already have some of Ted's 10.5 to 1 pistons and a mild cam from Woody, have an eldebrock manifold and eldebrock 4 barrel. I have a MSD box and distributor. So what I am taking from Todd is, just get the heads rebuilt. When I get the heads done, is there anything in particular I should asking about?

About two years ago I noticed the start of a little smoke from the right head, this year it continues a little more. I assume that it is a valve. I have never gotten a good feeling on the timing.

I figure since the very first engine I rebuilt was my Triumph, and it was ten years ago, and the only expertise I had was the factory manual, I got my money's worth.
 
If you're getting smoke from the engine, it's either oil getting down one of the valve guides, or oil getting by a bad piston ring. Do a compression test and if possible a leakdown test before you pull it apart. That will provide good intel on where the smoke is coming from. Lately I've seen some pretty badly scored bores from overly aggressive cams causing cylinder gas washdown. I have also seen badly smoking engines caused by oil going down the valve guides. Only seen that on engines fitted with roller rockers, as the roller rockers have a oil squirter that points directly at the valves. Great on race engines where you have extremely high lift and lots of heat buildup in the valve springs that needs cooling. A big problem on street engines- unless you enjoy fogging for mosquitos! Rover V8s didn't use valve seals until the very end of the 4.0 and 4.6 production runs. They were not needed because the stock rockers just don't push much oil into the valve covers. Some, but not much. If you are getting oil down the valves, you can install positive valve seals or you can machine out the guides and install bullet inserts, or both. My suggestion is to just send the heads to a local shop and have them cleaned up. The heads are no different than any other head. Nothing mystical about them that needs sending them half way across the country to a middle man "specialist". They'll check to make sure the valves are in decent shape and seating properly. Strongly consider replacing your cam. I haven't seen a non worn cam come out of an engine in years because of the lack of ZDDP in oils now.
 
Hi, my name is Tom, I would suggest checking the compression before taking the heads off. if compression is low add a little oil to thoes cylinders and recheck the comp. if it improves then you need to redo the engine. maybe all you need is new rings. while it is open new main,rod and cam bearings. the 3.5 is a good engine try to keep it that way. they use thoes engines in mini hot rod tractors. tom
 
PATR8 said:
It has been 10 years + since I rebuilt the engine, what else should I do.
Click to expand...

This comment just scares me to death. 10 years? That's not very long...gulp....

My car has the original engine & drive train. I have had it since 1987 and have only replaced some accessories. Original cam, heads, clutch, tranny & rear end. I have swapped speedos so I am not 100% sure on mileage but it is well over 170,000 miles.

Guess my cam might be slightly worn by now... :smile:

Some day it is just going to go BOOM :frown:
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Some day it is just going to go BOOM[/QUOTE]

Cross that bridge when you come to it, or you will fall into the British car owner trap of "while I'm in there".

Take that from one who knows only too well how that program works....
 
I would say ten years is not long unless it was the first engine you ever rebuilt and you rebuilt in using the factory manual with little other expertise
 
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