I have a 2.5L in my Spit bodied GT6 that is a street only vehicle. Engine
built up as follows: Head milled 0.135 & port matching & mild porting
about the valve guide bosses, "S2" cam grind from BPNW, triple Weber
DCOEs, 6 into 1 headers and an Aluminum flywheel from PAECO (say NO!, NO!,
NO! to PAECO!). At about 65K miles the head gasket burned thru and once I
had the head off and checked the cam, I found out that several of the cam
lobes were wiped out. As part of the head gasket replacement: Now the head
has 0.140+ removed, head studs instead of bolts, GoodParts bronze valve
guides & Teflon seals (for the valve stems) and a GP2 cam. Subjectively,
the S2 (before the lobes were wiped out)and the GP2 have a very similar
performance. I now make sure that I run oil with a high ZDDP content.
About 20K miles on the repaired motor.
If money is a consideration, I would suggest that you consider using a GT6
flywheel instead of an aluminum one. I saw the slug of metal that the
2.5L flywheel is and assumed the GT6 one was the same. AFTER all my
troubles with the PAECO flywheel, I discovered that the 2.0L flywheel is
substantially lighter. In round numbers: 30 lbs TR6 flywheel, 18 lbs GT6
and my "street" aluminum "TR6" one comes in at 12 lbs. I bought my
flywheel about the time that Al Gore invented the Internet and IO did not
do a search on PAECO - now there are adequate reports of their products /
service. My flywheel has a spray-braised ceramic (?) surface for the
friction surface. I get to replace clutch discs every 15K miles.
> I recently asked for experiences and opinions on 6 cyl camshafts on the
> 6-Pack list and didn't receive as many responses as I had hoped for, so I
> thought I would address this list with the same question. For those people
> who are on both lists, I apologize and ask that you just skip over this
> I am in the process of laying out the rebuild of my 2.5L 6-cyl and am
> trying to decide which cam would be best for my use. I know this is a grey
> area for many people and opinion is easier than fact, but I think the
> members of this list are probably the best resource available to help me
> This is going to be for a street car, not a track runner. I live in an
> area with lots of hills and winding roads, which I prefer over highway
> Here's what I have decided so far:
> I have the late model engine & head which will be balanced and blueprinted
> with the head ported and CR raised to 9.5:1 or 10:1, and an aluminum
> flywheel and fan eliminator added; I plan on the 1.65:1 roller rocker
> setup; I'll be adding EFI (haven't decided on a system yet, but leaning
> towards MPI over TBI) & an EDIS system; 6-3-1 headers w/ free-flow exhaust
> system. I already have an A-Type overdrive for those times I will be
> cruising on the freeway.
> My early favorites are the TR5 profile, Richard Good's GP2 or TSI's S-2.
> The 6-Pack list query has brought another cam into consideration: Isky
> Z-19. If you have another cam you're really happy with, please suggest it,
> or give me your experiences with the above. I will report the results
> (and my decision) once I have received all responses.
> Thanks in advance,
> Raymond L. Hatfield
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